Quote vars in entrypoint.sh to prevent unwanted argument split (#420)

Prevents arguments from being split when e.g. the RUNNER_GROUP variable contains spaces (which is legit. One can create such groups in GitHub).

I've seen that all workers with group names that contain no spaces can register successfully, while all workers with groups that contain spaces will not register.

Furthermore, I suppose also other chars can be used here to inject arbitrary commands in an unsupported way via e.g. pipe symbol.

Quoting the vars correctly should prevent that and allow for e.g. group names and runner labels with spaces and other bash reserved characters.

Makefile

@@ -14,6 +14,8 @@ else
 GOBIN=$(shell go env GOBIN)
 endif
 
+TEST_ASSETS=$(PWD)/test-assets
+
 # default list of platforms for which multiarch image is built
 ifeq (${PLATFORMS}, )
 	export PLATFORMS="linux/amd64,linux/arm64"
@@ -37,6 +39,13 @@ all: manager
 test: generate fmt vet manifests
 	go test ./... -coverprofile cover.out
 
+test-with-deps: kube-apiserver etcd kubectl
+	# See https://pkg.go.dev/sigs.k8s.io/controller-runtime/pkg/envtest#pkg-constants
+	TEST_ASSET_KUBE_APISERVER=$(KUBE_APISERVER_BIN) \
+	TEST_ASSET_ETCD=$(ETCD_BIN) \
+	TEST_ASSET_KUBECTL=$(KUBECTL_BIN) \
+	  make test
+
 # Build manager binary
 manager: generate fmt vet
 	go build -o bin/manager main.go
@@ -191,3 +200,66 @@ ifeq (, $(wildcard $(GOBIN)/yq))
 	}
 endif
 YQ=$(GOBIN)/yq
+
+OS_NAME := $(shell uname -s | tr A-Z a-z)
+
+# find or download etcd
+etcd:
+ifeq (, $(wildcard $(TEST_ASSETS)/etcd))
+	@{ \
+	set -xe ;\
+	INSTALL_TMP_DIR=$$(mktemp -d) ;\
+	cd $$INSTALL_TMP_DIR ;\
+	wget https://github.com/kubernetes-sigs/kubebuilder/releases/download/v2.3.2/kubebuilder_2.3.2_$(OS_NAME)_amd64.tar.gz ;\
+	mkdir -p $(TEST_ASSETS) ;\
+	tar zxvf kubebuilder_2.3.2_$(OS_NAME)_amd64.tar.gz ;\
+	mv kubebuilder_2.3.2_$(OS_NAME)_amd64/bin/etcd $(TEST_ASSETS)/etcd ;\
+	mv kubebuilder_2.3.2_$(OS_NAME)_amd64/bin/kube-apiserver $(TEST_ASSETS)/kube-apiserver ;\
+	mv kubebuilder_2.3.2_$(OS_NAME)_amd64/bin/kubectl $(TEST_ASSETS)/kubectl ;\
+	rm -rf $$INSTALL_TMP_DIR ;\
+	}
+ETCD_BIN=$(TEST_ASSETS)/etcd
+else
+ETCD_BIN=$(TEST_ASSETS)/etcd
+endif
+
+# find or download kube-apiserver
+kube-apiserver:
+ifeq (, $(wildcard $(TEST_ASSETS)/kube-apiserver))
+	@{ \
+	set -xe ;\
+	INSTALL_TMP_DIR=$$(mktemp -d) ;\
+	cd $$INSTALL_TMP_DIR ;\
+	wget https://github.com/kubernetes-sigs/kubebuilder/releases/download/v2.3.2/kubebuilder_2.3.2_$(OS_NAME)_amd64.tar.gz ;\
+	mkdir -p $(TEST_ASSETS) ;\
+	tar zxvf kubebuilder_2.3.2_$(OS_NAME)_amd64.tar.gz ;\
+	mv kubebuilder_2.3.2_$(OS_NAME)_amd64/bin/etcd $(TEST_ASSETS)/etcd ;\
+	mv kubebuilder_2.3.2_$(OS_NAME)_amd64/bin/kube-apiserver $(TEST_ASSETS)/kube-apiserver ;\
+	mv kubebuilder_2.3.2_$(OS_NAME)_amd64/bin/kubectl $(TEST_ASSETS)/kubectl ;\
+	rm -rf $$INSTALL_TMP_DIR ;\
+	}
+KUBE_APISERVER_BIN=$(TEST_ASSETS)/kube-apiserver
+else
+KUBE_APISERVER_BIN=$(TEST_ASSETS)/kube-apiserver
+endif
+
+
+# find or download kubectl
+kubectl:
+ifeq (, $(wildcard $(TEST_ASSETS)/kubectl))
+	@{ \
+	set -xe ;\
+	INSTALL_TMP_DIR=$$(mktemp -d) ;\
+	cd $$INSTALL_TMP_DIR ;\
+	wget https://github.com/kubernetes-sigs/kubebuilder/releases/download/v2.3.2/kubebuilder_2.3.2_$(OS_NAME)_amd64.tar.gz ;\
+	mkdir -p $(TEST_ASSETS) ;\
+	tar zxvf kubebuilder_2.3.2_$(OS_NAME)_amd64.tar.gz ;\
+	mv kubebuilder_2.3.2_$(OS_NAME)_amd64/bin/etcd $(TEST_ASSETS)/etcd ;\
+	mv kubebuilder_2.3.2_$(OS_NAME)_amd64/bin/kube-apiserver $(TEST_ASSETS)/kube-apiserver ;\
+	mv kubebuilder_2.3.2_$(OS_NAME)_amd64/bin/kubectl $(TEST_ASSETS)/kubectl ;\
+	rm -rf $$INSTALL_TMP_DIR ;\
+	}
+KUBECTL_BIN=$(TEST_ASSETS)/kubectl
+else
+KUBECTL_BIN=$(TEST_ASSETS)/kubectl
+endif

README.md

@@ -10,8 +10,8 @@ ToC:
 - [Installation](#installation)
   - [GitHub Enterprise support](#github-enterprise-support)
 - [Setting up authentication with GitHub API](#setting-up-authentication-with-github-api)
-  - [Using GitHub App](#using-github-app)
-  - [Using Personal AccessToken ](#using-personal-access-token)
+  - [Deploying using GitHub App Authentication](#deploying-using-github-app-authentication)
+  - [Deploying using PAT Authentication](#deploying-using-pat-authentication)
 - [Usage](#usage)
   - [Repository Runners](#repository-runners)
   - [Organization Runners](#organization-runners)
@@ -21,7 +21,7 @@ ToC:
   - [Runner with DinD](#runner-with-dind)
   - [Additional tweaks](#additional-tweaks)
   - [Runner labels](#runner-labels)
-  - [Runer groups](#runner-groups)
+  - [Runner groups](#runner-groups)
   - [Using EKS IAM role for service accounts](#using-eks-iam-role-for-service-accounts)
   - [Software installed in the runner image](#software-installed-in-the-runner-image)
   - [Common errors](#common-errors)
@@ -44,14 +44,14 @@ Install the custom resource and actions-runner-controller with `kubectl` or `hel
 
 `kubectl`:
 
-```
-# REPLACE "v0.16.1" with the latest release
-kubectl apply -f https://github.com/summerwind/actions-runner-controller/releases/download/v0.16.1/actions-runner-controller.yaml
+```shell
+# REPLACE "v0.17.0" with the version you wish to deploy
+kubectl apply -f https://github.com/summerwind/actions-runner-controller/releases/download/v0.17.0/actions-runner-controller.yaml
 ```
 
 `helm`:
 
-```
+```shell
 helm repo add actions-runner-controller https://summerwind.github.io/actions-runner-controller
 helm upgrade --install -n actions-runner-system actions-runner-controller/actions-runner-controller
 ```
@@ -61,8 +61,7 @@ helm upgrade --install -n actions-runner-system actions-runner-controller/action
 If you use either Github Enterprise Cloud or Server, you can use **actions-runner-controller**  with those, too.
 Authentication works same way as with public Github (repo and organization level).
 The minimum version of Github Enterprise Server is 3.0.0 (or rc1/rc2).
-In most cases maintainers do not have environment where to test changes and are reliant on the community for testing.
-
+__**NOTE : The maintainers do not have an Enterprise environment to be able to test changes and so are reliant on the community for testing, support is a best endeavors basis only and is community driven**__
 
 ```shell
 kubectl set env deploy controller-manager -c manager GITHUB_ENTERPRISE_URL=<GHEC/S URL> --namespace actions-runner-system
@@ -108,20 +107,14 @@ spec:
 
 ## Setting up authentication with GitHub API
 
-There are two ways for actions-runner-controller to authenticate with the GitHub API:
+There are two ways for actions-runner-controller to authenticate with the GitHub API (only 1 can be configured at a time however):
 
 1. Using GitHub App.
 2. Using Personal Access Token.
 
-Regardless of which authentication method you use, the same permissions are required, those permissions are:
-- Repository: Administration (read/write)
-- Repository: Actions (read)
-- Organization: Self-hosted runners (read/write)
+Functionality wise there isn't a difference between the 2 authentication methods. There are however some benefits to using a GitHub App for authentication over a PAT such as an [increased API quota](https://docs.github.com/en/developers/apps/rate-limits-for-github-apps), if you run into rate limiting consider deploying this solution using GitHub App authentication instead.
 
-
-**NOTE: It is extremely important to only follow one of the sections below and not both.**
-
-### Using GitHub App
+### Deploying using GitHub App Authentication
 
 You can create a GitHub App for either your account or any organization. If you want to create a GitHub App for your account, open the following link to the creation page, enter any unique name in the "GitHub App name" field, and hit the "Create GitHub App" button at the bottom of the page.
 
@@ -158,19 +151,29 @@ $ kubectl create secret generic controller-manager \
     --from-file=github_app_private_key=${PRIVATE_KEY_FILE_PATH}
 ```
 
-### Using Personal Access Token
+### Deploying using PAT Authentication
 
-From an account that has `admin` privileges for the repository, create a [personal access token](https://github.com/settings/tokens) with `repo` scope. This token is used to register a self-hosted runner by *actions-runner-controller*.
+Personal Acess Token can be used to register a self-hosted runner by *actions-runner-controller*.
 
-Self-hosted runners in GitHub can either be connected to a single repository, or to a GitHub organization (so they are available to all repositories in the organization). This token is used to register a self-hosted runner by *actions-runner-controller*.
+Self-hosted runners in GitHub can either be connected to a single repository, or to a GitHub organization (so they are available to all repositories in the organization). How you plan on using the runner will affect what scopes are needed for the token.
 
-For adding a runner to a repository, the token should have `repo` scope. If the runner should be added to an organization, the token should have `admin:org` scope. Note that to use a Personal Access Token, you must issue the token with an account that has `admin` privileges (on the repository and/or the organization).
+Log-in to a GitHub account that has `admin` privileges for the repository, and [create a personal access token](https://github.com/settings/tokens/new) with the appropriate scopes listed below:
 
-Open the Create Token page from the following link, grant the `repo` and/or `admin:org` scope, and press the "Generate Token" button at the bottom of the page to create the token.
+**Scopes for a Repository Runner**
 
-- [Create personal access token](https://github.com/settings/tokens/new)
+* repo (Full control)
 
-Register the created token (`GITHUB_TOKEN`) as a Kubernetes secret.
+**Scopes for a Organization Runner**
+
+* repo (Full control)
+* admin:org (Full control)
+* admin:public_key - read:public_key
+* admin:repo_hook - read:repo_hook
+* admin:org_hook
+* notifications
+* workflow
+
+Once you have created the appropriate token, deploy it as a secret to your kubernetes cluster that you are going to deploy the solution on:
 
 ```shell
 kubectl create secret generic controller-manager \
@@ -185,7 +188,7 @@ There are two ways to use this controller:
 - Manage runners one by one with `Runner`.
 - Manage a set of runners with `RunnerDeployment`.
 
-### Repository runners
+### Repository Runners
 
 To launch a single self-hosted runner, you need to create a manifest file includes *Runner* resource as follows. This example launches a self-hosted runner with name *example-runner* for the *summerwind/actions-runner-controller* repository.
 
@@ -283,9 +286,33 @@ example-runnerdeploy2475ht2qbr   mumoshu/actions-runner-controller-ci   Running
 
 #### Autoscaling
 
-`RunnerDeployment` can scale the number of runners between `minReplicas` and `maxReplicas` fields, depending on pending workflow runs.
+A `RunnerDeployment` can scale the number of runners between `minReplicas` and `maxReplicas` fields based the chosen scaling metric as defined in the `metrics` attribute
+
+**Scaling Metrics**
+
+**TotalNumberOfQueuedAndInProgressWorkflowRuns**
+
+In the below example, `actions-runner` will poll GitHub for all pending workflows with the poll period defined by the sync period configuration. It will then scale to e.g. 3 if there're 3 pending jobs at sync time.
+With this scaling metric we are required to define a list of repositories within our metric.
+
+The scale out performance is controlled via the manager containers startup `--sync-period` argument. The default value is set to 10 minutes to prevent default deployments rate limiting themselves from the GitHub API.
+
+**Kustomize Config :** The period can be customised in the `config/default/manager_auth_proxy_patch.yaml` patch<br />
+**Helm Config :** `syncPeriod`
+
+**Benefits of this metric**
+1. Supports named repositories allowing you to restrict the runner to a specified set of repositories server side.
+2. Scales the runner count based on the actual queue depth of the jobs meaning a more 1:1 scaling of runners to queued jobs.
+3. Like all scaling metrics, you can manage workflow allocation to the RunnerDeployment through the use of [Github labels](#runner-labels).
+
+**Drawbacks of this metric**
+1. Repositories must be named within the scaling metric, maintaining a list of repositories may not be viable in larger environments or self-serve environments.
+2. May not scale quick enough for some users needs. This metric is pull based and so the queue depth is polled as configured by the sync period, as a result scaling performance is bound by this sync period meaning there is a lag to scaling activity.
+3. Relatively large amounts of API requests required to maintain this metric, you may run in API rate limiting issues depending on the size of your environment and how aggressive your sync period configuration is
+
+
+Example `RunnerDeployment` backed by a `HorizontalRunnerAutoscaler`
 
-In the below example, `actions-runner` checks for pending workflow runs for each sync period, and scale to e.g. 3 if there're 3 pending jobs at sync time.
 
 ```yaml
 apiVersion: actions.summerwind.dev/v1alpha1
@@ -312,38 +339,34 @@ spec:
     - summerwind/actions-runner-controller
 ```
 
-The scale out performance is controlled via the manager containers startup `--sync-period` argument. The default value is 10 minutes to prevent unconfigured deployments rate limiting themselves from the GitHub API. The period can be customised in the `config/default/manager_auth_proxy_patch.yaml` patch for those that are building the solution via the kustomize setup.
-
-Additionally, the autoscaling feature has an anti-flapping option that prevents periodic loop of scaling up and down.
-By default, it doesn't scale down until the grace period of 10 minutes passes after a scale up. The grace period can be configured by setting `scaleDownDelaySecondsAfterScaleUp`:
+Additionally, the `HorizontalRunnerAutoscaler` also has an anti-flapping option that prevents periodic loop of scaling up and down.
+By default, it doesn't scale down until the grace period of 10 minutes passes after a scale up. The grace period can be configured however by adding the setting `scaleDownDelaySecondsAfterScaleOut` in the `HorizontalRunnerAutoscaler` `spec`:
 
 ```yaml
-apiVersion: actions.summerwind.dev/v1alpha1
-kind: RunnerDeployment
-metadata:
-  name: example-runner-deployment
 spec:
-  template:
-    spec:
-      repository: summerwind/actions-runner-controller
----
-apiVersion: actions.summerwind.dev/v1alpha1
-kind: HorizontalRunnerAutoscaler
-metadata:
-  name: example-runner-deployment-autoscaler
-spec:
-  scaleTargetRef:
-    name: example-runner-deployment
-  minReplicas: 1
-  maxReplicas: 3
   scaleDownDelaySecondsAfterScaleOut: 60
-  metrics:
-  - type: TotalNumberOfQueuedAndInProgressWorkflowRuns
-    repositoryNames:
-    - summerwind/actions-runner-controller
 ```
 
-If you do not want to manage an explicit list of repositories to scale, an alternate autoscaling scheme that can be applied is the PercentageRunnersBusy scheme. The number of desired pods are evaulated by checking how many runners are currently busy and applying a scaleup or scale down factor if certain thresholds are met. By setting the metric type to PercentageRunnersBusy, the HorizontalRunnerAutoscaler will query github for the number of busy runners which live in the RunnerDeployment namespace. Scaleup and scaledown thresholds are the percentage of busy runners at which the number of desired runners are re-evaluated. Scaleup and scaledown factors are the multiplicative factor applied to the current number of runners used to calculate the number of desired runners. This scheme is also especially useful if you want multiple controllers in various clusters, each responsible for scaling their own runner pods per namespace.
+**PercentageRunnersBusy**
+
+The `HorizontalRunnerAutoscaler` will poll GitHub based on the configuration sync period for the number of busy runners which live in the RunnerDeployment's namespace and scale based on the settings
+
+**Kustomize Config :** The period can be customised in the `config/default/manager_auth_proxy_patch.yaml` patch<br />
+**Helm Config :** `syncPeriod`
+
+**Benefits of this metric**
+1. Supports named repositories server side the same as the `TotalNumberOfQueuedAndInProgressWorkflowRuns` metric [#313](https://github.com/summerwind/actions-runner-controller/pull/313)
+2. Supports GitHub organisation wide scaling without maintaining an explicit list of repositories, this is especially useful for those that are working at a larger scale. [#223](https://github.com/summerwind/actions-runner-controller/pull/223)
+3. Like all scaling metrics, you can manage workflow allocation to the RunnerDeployment through the use of [Github labels](#runner-labels)
+4. Supports scaling desired runner count on both a percentage increase / decrease basis as well as on a fixed increase / decrease count basis [#223](https://github.com/summerwind/actions-runner-controller/pull/223) [#315](https://github.com/summerwind/actions-runner-controller/pull/315)
+
+**Drawbacks of this metric**
+1. May not scale quick enough for some users needs. This metric is pull based and so the number of busy runners are polled as configured by the sync period, as a result scaling performance is bound by this sync period meaning there is a lag to scaling activity.
+2. We are scaling up and down based on indicative information rather than a count of the actual number of queued jobs and so the desired runner count is likely to under provision new runners or overprovision them relative to actual job queue depth, this may or may not be a problem for you.
+
+
+Examples of each scaling type implemented with a `RunnerDeployment` backed by a `HorizontalRunnerAutoscaler`:
+
 
 ```yaml
 ---
@@ -356,13 +379,38 @@ spec:
     name: example-runner-deployment
   minReplicas: 1
   maxReplicas: 3
-  scaleDownDelaySecondsAfterScaleOut: 60
   metrics:
   - type: PercentageRunnersBusy
-    scaleUpThreshold: '0.75'
-    scaleDownThreshold: '0.3'
-    scaleUpFactor: '1.4'
-    scaleDownFactor: '0.7'
+    scaleUpThreshold: '0.75'    # The percentage of busy runners at which the number of desired runners are re-evaluated to scale up
+    scaleDownThreshold: '0.3'   # The percentage of busy runners at which the number of desired runners are re-evaluated to scale down
+    scaleUpFactor: '1.4'        # The scale up multiplier factor applied to desired count
+    scaleDownFactor: '0.7'      # The scale down multiplier factor applied to desired count
+```
+
+```yaml
+---
+apiVersion: actions.summerwind.dev/v1alpha1
+kind: HorizontalRunnerAutoscaler
+metadata:
+  name: example-runner-deployment-autoscaler
+spec:
+  scaleTargetRef:
+    name: example-runner-deployment
+  minReplicas: 1
+  maxReplicas: 3
+  metrics:
+  - type: PercentageRunnersBusy
+    scaleUpThreshold: '0.75'    # The percentage of busy runners at which the number of desired runners are re-evaluated to scale up
+    scaleDownThreshold: '0.3'   # The percentage of busy runners at which the number of desired runners are re-evaluated to scale down
+    ScaleUpAdjustment: '2'      # The scale up runner count added to desired count
+    ScaleDownAdjustment: '1'    # The scale down runner count subtracted from the desired count
+```
+
+Like the previous metric, the scale down factor respects the anti-flapping configuration is applied to the `HorizontalRunnerAutoscaler` as mentioned previously:
+
+```yaml
+spec:
+  scaleDownDelaySecondsAfterScaleOut: 60
 ```
 
 #### Faster Autoscaling with GitHub Webhook
@@ -371,11 +419,11 @@ spec:
 > Please get prepared to put some time and effort to learn and leverage this feature!
 
 `actions-runner-controller` has an optional Webhook server that receives GitHub Webhook events and scale
-[`RunnerDeployment`s](#runnerdeployments) by updating corresponding [`HorizontalRunnerAutoscaler`s](#autoscaling).
+[`RunnerDeployments`](#runnerdeployments) by updating corresponding [`HorizontalRunnerAutoscalers`](#autoscaling).
 
 Today, the Webhook server can be configured to respond GitHub `check_run`, `pull_request`, and `push` events
 by scaling up the matching `HorizontalRunnerAutoscaler` by N replica(s), where `N` is configurable within
-`HorizontalRunerAutoscaler`'s `Spec`.
+`HorizontalRunerAutoscaler's` `Spec`.
 
 More concretely, you can configure the targeted GitHub event types and the `N` in
 `scaleUpTriggers`:
@@ -385,7 +433,7 @@ kind: HorizontalRunnerAutoscaler
 spec:
   scaleTargetRef:
     name: myrunners
-  scaleUpTrigggers:
+  scaleUpTriggers:
   - githubEvent:
       checkRun:
         types: ["created"]
@@ -444,7 +492,7 @@ kind: HorizontalRunnerAutoscaler
 spec:
   scaleTargetRef:
     name: myrunners
-  scaleUpTrigggers:
+  scaleUpTriggers:
   - githubEvent:
       checkRun:
         types: ["created"]
@@ -466,7 +514,7 @@ kind: HorizontalRunnerAutoscaler
 spec:
   scaleTargetRef:
     name: myrunners
-  scaleUpTrigggers:
+  scaleUpTriggers:
   - githubEvent:
       pullRequest:
         types: ["synchronize"]
@@ -531,20 +579,20 @@ spec:
         requests:
           cpu: "2.0"
           memory: "4Gi"
-
       # Timeout after a node crashed or became unreachable to evict your pods somewhere else (default 5mins)
       tolerations:
         - key: "node.kubernetes.io/unreachable"
           operator: "Exists"
           effect: "NoExecute"
           tolerationSeconds: 10
-
+      # true (default) = A privileged docker sidecar container is included in the runner pod.
+      # false = A docker sidecar container is not included in the runner pod and you can't use docker.
       # If set to false, there are no privileged container and you cannot use docker.
       dockerEnabled: false
-      # If set to true, runner pod container only 1 container that's expected to be able to run docker, too.
-      # image summerwind/actions-runner-dind or custom one should be used with true -value
-      dockerdWithinRunnerContainer: false
-      # Valid if dockerdWithinRunnerContainer is not true
+      # false (default) = Docker support is provided by a sidecar container deployed in the runner pod.
+      # true = No docker sidecar container is deployed in the runner pod but docker can be used within teh runner container instead. The image summerwind/actions-runner-dind is used by default.
+      dockerdWithinRunnerContainer: true
+      # Docker sidecar container image tweaks examples below, only applicable if dockerdWithinRunnerContainer = false
       dockerdContainerResources:
         limits:
           cpu: "4.0"
@@ -552,6 +600,7 @@ spec:
         requests:
           cpu: "2.0"
           memory: "4Gi"
+      # Additional N number of sidecar containers
       sidecarContainers:
         - name: mysql
           image: mysql:5.7
@@ -560,8 +609,8 @@ spec:
               value: abcd1234
           securityContext:
             runAsUser: 0
-      # if workDir is not specified, the default working directory is /runner/_work
-      # this setting allows you to customize the working directory location
+      # workDir if not specified (default = /runner/_work)
+      # You can customise this setting allowing you to change the default working directory location
       # for example, the below setting is the same as on the ubuntu-18.04 image
       workDir: /home/runner/work
 ```
@@ -739,9 +788,11 @@ NAME=$DOCKER_USER/actions-runner-controller \
 The following is a list of alternative solutions that may better fit you depending on your use-case:
 
 - <https://github.com/evryfs/github-actions-runner-operator/>
+- <https://github.com/philips-labs/terraform-aws-github-runner/>
 
 Although the situation can change over time, as of writing this sentence, the benefits of using `actions-runner-controller` over the alternatives are:
 
 - `actions-runner-controller` has the ability to autoscale runners based on number of pending/progressing jobs (#99)
 - `actions-runner-controller` is able to gracefully stop runners (#103)
 - `actions-runner-controller` has ARM support
+- `actions-runner-controller` has GitHub Enterprise support (see [GitHub Enterprise support](#github-enterprise-support) section for caveats)

acceptance/testdata/runnerdeploy.yaml

@@ -7,3 +7,14 @@ spec:
   template:
     spec:
       repository: mumoshu/actions-runner-controller-ci
+      #
+      # dockerd within runner container
+      #
+      ## Replace `mumoshu/actions-runner-dind:dev` with your dind image
+      #dockerdWithinRunnerContainer: true
+      #image: mumoshu/actions-runner-dind:dev
+
+      #
+      # Set the MTU used by dockerd-managed network interfaces (including docker-build)
+      #
+      #dockerMTU: 1450

api/v1alpha1/horizontalrunnerautoscaler_types.go

@@ -72,6 +72,12 @@ type GitHubEventScaleUpTriggerSpec struct {
 type CheckRunSpec struct {
 	Types  []string `json:"types,omitempty"`
 	Status string   `json:"status,omitempty"`
+
+	// Names is a list of GitHub Actions glob patterns.
+	// Any check_run event whose name matches one of patterns in the list can trigger autoscaling.
+	// Note that check_run name seem to equal to the job name you've defined in your actions workflow yaml file.
+	// So it is very likely that you can utilize this to trigger depending on the job.
+	Names []string `json:"names,omitempty"`
 }
 
 // https://docs.github.com/en/actions/reference/events-that-trigger-workflows#pull_request
@@ -150,6 +156,7 @@ type HorizontalRunnerAutoscalerStatus struct {
 	DesiredReplicas *int `json:"desiredReplicas,omitempty"`
 
 	// +optional
+	// +nullable
 	LastSuccessfulScaleOutTime *metav1.Time `json:"lastSuccessfulScaleOutTime,omitempty"`
 
 	// +optional

api/v1alpha1/runner_types.go

@@ -92,6 +92,8 @@ type RunnerSpec struct {
 	DockerdWithinRunnerContainer *bool `json:"dockerdWithinRunnerContainer,omitempty"`
 	// +optional
 	DockerEnabled *bool `json:"dockerEnabled,omitempty"`
+	// +optional
+	DockerMTU *int64 `json:"dockerMTU,omitempty"`
 }
 
 // ValidateRepository validates repository field.
@@ -119,10 +121,17 @@ func (rs *RunnerSpec) ValidateRepository() error {
 
 // RunnerStatus defines the observed state of Runner
 type RunnerStatus struct {
+	// +optional
 	Registration RunnerStatusRegistration `json:"registration"`
-	Phase        string                   `json:"phase"`
-	Reason       string                   `json:"reason"`
-	Message      string                   `json:"message"`
+	// +optional
+	Phase string `json:"phase,omitempty"`
+	// +optional
+	Reason string `json:"reason,omitempty"`
+	// +optional
+	Message string `json:"message,omitempty"`
+	// +optional
+	// +nullable
+	LastRegistrationCheckTime *metav1.Time `json:"lastRegistrationCheckTime,omitempty"`
 }
 
 // RunnerStatusRegistration contains runner registration status

api/v1alpha1/runnerdeployment_types.go

@@ -25,12 +25,15 @@ const (
 	AutoscalingMetricTypePercentageRunnersBusy                        = "PercentageRunnersBusy"
 )
 
-// RunnerReplicaSetSpec defines the desired state of RunnerDeployment
+// RunnerDeploymentSpec defines the desired state of RunnerDeployment
 type RunnerDeploymentSpec struct {
 	// +optional
 	// +nullable
 	Replicas *int `json:"replicas,omitempty"`
 
+	// +optional
+	// +nullable
+	Selector *metav1.LabelSelector `json:"selector"`
 	Template RunnerTemplate        `json:"template"`
 }
 

api/v1alpha1/runnerreplicaset_types.go

@@ -26,6 +26,9 @@ type RunnerReplicaSetSpec struct {
 	// +nullable
 	Replicas *int `json:"replicas,omitempty"`
 
+	// +optional
+	// +nullable
+	Selector *metav1.LabelSelector `json:"selector"`
 	Template RunnerTemplate        `json:"template"`
 }
 

api/v1alpha1/zz_generated.deepcopy.go

@@ -22,6 +22,7 @@ package v1alpha1
 
 import (
 	"k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 )
 
@@ -65,6 +66,11 @@ func (in *CheckRunSpec) DeepCopyInto(out *CheckRunSpec) {
 		*out = make([]string, len(*in))
 		copy(*out, *in)
 	}
+	if in.Names != nil {
+		in, out := &in.Names, &out.Names
+		*out = make([]string, len(*in))
+		copy(*out, *in)
+	}
 }
 
 // DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new CheckRunSpec.
@@ -403,6 +409,11 @@ func (in *RunnerDeploymentSpec) DeepCopyInto(out *RunnerDeploymentSpec) {
 		*out = new(int)
 		**out = **in
 	}
+	if in.Selector != nil {
+		in, out := &in.Selector, &out.Selector
+		*out = new(metav1.LabelSelector)
+		(*in).DeepCopyInto(*out)
+	}
 	in.Template.DeepCopyInto(&out.Template)
 }
 
@@ -535,6 +546,11 @@ func (in *RunnerReplicaSetSpec) DeepCopyInto(out *RunnerReplicaSetSpec) {
 		*out = new(int)
 		**out = **in
 	}
+	if in.Selector != nil {
+		in, out := &in.Selector, &out.Selector
+		*out = new(metav1.LabelSelector)
+		(*in).DeepCopyInto(*out)
+	}
 	in.Template.DeepCopyInto(&out.Template)
 }
 
@@ -678,6 +694,11 @@ func (in *RunnerSpec) DeepCopyInto(out *RunnerSpec) {
 		*out = new(bool)
 		**out = **in
 	}
+	if in.DockerMTU != nil {
+		in, out := &in.DockerMTU, &out.DockerMTU
+		*out = new(int64)
+		**out = **in
+	}
 }
 
 // DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new RunnerSpec.
@@ -694,6 +715,10 @@ func (in *RunnerSpec) DeepCopy() *RunnerSpec {
 func (in *RunnerStatus) DeepCopyInto(out *RunnerStatus) {
 	*out = *in
 	in.Registration.DeepCopyInto(&out.Registration)
+	if in.LastRegistrationCheckTime != nil {
+		in, out := &in.LastRegistrationCheckTime, &out.LastRegistrationCheckTime
+		*out = (*in).DeepCopy()
+	}
 }
 
 // DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new RunnerStatus.

charts/actions-runner-controller/Chart.yaml

@@ -15,7 +15,7 @@ type: application
 # This is the chart version. This version number should be incremented each time you make changes
 # to the chart and its templates, including the app version.
 # Versions are expected to follow Semantic Versioning (https://semver.org/)
-version: 0.6.0
+version: 0.10.4
 
 home: https://github.com/summerwind/actions-runner-controller
 

charts/actions-runner-controller/ci/ci-values.yaml

@@ -22,6 +22,9 @@ resources:
     cpu: 100m
     memory: 128Mi  
 
+authSecret:
+  create: false
+
 # Set the following to true to create a dummy secret, allowing the manager pod to start
 # This is only useful in CI
 createDummySecret: true

charts/actions-runner-controller/crds/actions.summerwind.dev_horizontalrunnerautoscalers.yaml

@@ -148,6 +148,17 @@ spec:
                       checkRun:
                         description: https://docs.github.com/en/actions/reference/events-that-trigger-workflows#check_run
                         properties:
+                          names:
+                            description: Names is a list of GitHub Actions glob patterns.
+                              Any check_run event whose name matches one of patterns
+                              in the list can trigger autoscaling. Note that check_run
+                              name seem to equal to the job name you've defined in
+                              your actions workflow yaml file. So it is very likely
+                              that you can utilize this to trigger depending on the
+                              job.
+                            items:
+                              type: string
+                            type: array
                           status:
                             type: string
                           types:
@@ -196,6 +207,7 @@ spec:
               type: integer
             lastSuccessfulScaleOutTime:
               format: date-time
+              nullable: true
               type: string
             observedGeneration:
               description: ObservedGeneration is the most recent generation observed

charts/actions-runner-controller/crds/actions.summerwind.dev_runnerdeployments.yaml

@@ -38,11 +38,42 @@ spec:
         metadata:
           type: object
         spec:
-          description: RunnerReplicaSetSpec defines the desired state of RunnerDeployment
+          description: RunnerDeploymentSpec defines the desired state of RunnerDeployment
           properties:
             replicas:
               nullable: true
               type: integer
+            selector:
+              description: A label selector is a label query over a set of resources. The result of matchLabels and matchExpressions are ANDed. An empty label selector matches all objects. A null label selector matches no objects.
+              nullable: true
+              properties:
+                matchExpressions:
+                  description: matchExpressions is a list of label selector requirements. The requirements are ANDed.
+                  items:
+                    description: A label selector requirement is a selector that contains values, a key, and an operator that relates the key and values.
+                    properties:
+                      key:
+                        description: key is the label key that the selector applies to.
+                        type: string
+                      operator:
+                        description: operator represents a key's relationship to a set of values. Valid operators are In, NotIn, Exists and DoesNotExist.
+                        type: string
+                      values:
+                        description: values is an array of string values. If the operator is In or NotIn, the values array must be non-empty. If the operator is Exists or DoesNotExist, the values array must be empty. This array is replaced during a strategic merge patch.
+                        items:
+                          type: string
+                        type: array
+                    required:
+                      - key
+                      - operator
+                    type: object
+                  type: array
+                matchLabels:
+                  additionalProperties:
+                    type: string
+                  description: matchLabels is a map of {key,value} pairs. A single {key,value} in the matchLabels map is equivalent to an element of matchExpressions, whose key field is "key", the operator is "In", and the values array contains only "value". The requirements are ANDed.
+                  type: object
+              type: object
             template:
               properties:
                 metadata:
@@ -402,6 +433,9 @@ spec:
                       type: array
                     dockerEnabled:
                       type: boolean
+                    dockerMTU:
+                      format: int64
+                      type: integer
                     dockerdContainerResources:
                       description: ResourceRequirements describes the compute resource requirements.
                       properties:

charts/actions-runner-controller/crds/actions.summerwind.dev_runnerreplicasets.yaml

@@ -43,6 +43,37 @@ spec:
             replicas:
               nullable: true
               type: integer
+            selector:
+              description: A label selector is a label query over a set of resources. The result of matchLabels and matchExpressions are ANDed. An empty label selector matches all objects. A null label selector matches no objects.
+              nullable: true
+              properties:
+                matchExpressions:
+                  description: matchExpressions is a list of label selector requirements. The requirements are ANDed.
+                  items:
+                    description: A label selector requirement is a selector that contains values, a key, and an operator that relates the key and values.
+                    properties:
+                      key:
+                        description: key is the label key that the selector applies to.
+                        type: string
+                      operator:
+                        description: operator represents a key's relationship to a set of values. Valid operators are In, NotIn, Exists and DoesNotExist.
+                        type: string
+                      values:
+                        description: values is an array of string values. If the operator is In or NotIn, the values array must be non-empty. If the operator is Exists or DoesNotExist, the values array must be empty. This array is replaced during a strategic merge patch.
+                        items:
+                          type: string
+                        type: array
+                    required:
+                      - key
+                      - operator
+                    type: object
+                  type: array
+                matchLabels:
+                  additionalProperties:
+                    type: string
+                  description: matchLabels is a map of {key,value} pairs. A single {key,value} in the matchLabels map is equivalent to an element of matchExpressions, whose key field is "key", the operator is "In", and the values array contains only "value". The requirements are ANDed.
+                  type: object
+              type: object
             template:
               properties:
                 metadata:
@@ -402,6 +433,9 @@ spec:
                       type: array
                     dockerEnabled:
                       type: boolean
+                    dockerMTU:
+                      format: int64
+                      type: integer
                     dockerdContainerResources:
                       description: ResourceRequirements describes the compute resource requirements.
                       properties:

charts/actions-runner-controller/crds/actions.summerwind.dev_runners.yaml

@@ -398,6 +398,9 @@ spec:
               type: array
             dockerEnabled:
               type: boolean
+            dockerMTU:
+              format: int64
+              type: integer
             dockerdContainerResources:
               description: ResourceRequirements describes the compute resource requirements.
               properties:
@@ -1538,6 +1541,10 @@ spec:
         status:
           description: RunnerStatus defines the observed state of Runner
           properties:
+            lastRegistrationCheckTime:
+              format: date-time
+              nullable: true
+              type: string
             message:
               type: string
             phase:
@@ -1566,11 +1573,6 @@ spec:
                 - expiresAt
                 - token
               type: object
-          required:
-            - message
-            - phase
-            - reason
-            - registration
           type: object
       type: object
   version: v1alpha1

charts/actions-runner-controller/templates/certificate.yaml

@@ -5,7 +5,7 @@ apiVersion: cert-manager.io/v1
 kind: Issuer
 metadata:
   name: {{ include "actions-runner-controller.selfsignedIssuerName" . }}
-  namespace: {{ .Namespace }}
+  namespace: {{ .Release.Namespace }}
 spec:
   selfSigned: {}
 ---
@@ -13,7 +13,7 @@ apiVersion: cert-manager.io/v1
 kind: Certificate
 metadata:
   name: {{ include "actions-runner-controller.servingCertName" . }}
-  namespace: {{ .Namespace }}
+  namespace: {{ .Release.Namespace }}
 spec:
   dnsNames:
   - {{ include "actions-runner-controller.webhookServiceName" . }}.{{ .Release.Namespace }}.svc

charts/actions-runner-controller/templates/deployment.yaml

@@ -35,6 +35,9 @@ spec:
         - "--enable-leader-election"
         - "--sync-period={{ .Values.syncPeriod }}"
         - "--docker-image={{ .Values.image.dindSidecarRepositoryAndTag }}"
+        {{- if .Values.scope.singleNamespace }}
+        - "--watch-namespace={{ default .Release.Namespace .Values.scope.watchNamespace }}"
+        {{- end }}
         command:
         - "/manager"
         env:

charts/actions-runner-controller/templates/githubwebhook.deployment.yaml

@@ -41,7 +41,7 @@ spec:
           valueFrom:
             secretKeyRef:
               key: github_webhook_secret_token
-              name: {{- include "actions-runner-controller-github-webhook-server.secretName" . }}
+              name: {{ include "actions-runner-controller-github-webhook-server.secretName" . }}
               optional: true
         {{- range $key, $val := .Values.githubWebhookServer.env }}
         - name: {{ $key }}

charts/actions-runner-controller/templates/githubwebhook.secrets.yaml

@@ -3,7 +3,7 @@
 apiVersion: v1
 kind: Secret
 metadata:
-  name: {{- include "actions-runner-controller-github-webhook-server.secretName" . }}
+  name: {{ include "actions-runner-controller-github-webhook-server.secretName" . }}
   namespace: {{ .Release.Namespace }}
   labels:
     {{- include "actions-runner-controller.labels" . | nindent 4 }}

charts/actions-runner-controller/templates/webhook_configs.yaml

@@ -1,10 +1,6 @@
 
 ---
-{{- if semverCompare ">=1.16-0" .Capabilities.KubeVersion.GitVersion -}}
-apiVersion: admissionregistration.k8s.io/v1
-{{- else -}}
 apiVersion: admissionregistration.k8s.io/v1beta1
-{{- end }}
 kind: MutatingWebhookConfiguration
 metadata:
   creationTimestamp: null
@@ -68,11 +64,7 @@ webhooks:
     - runnerreplicasets
 
 ---
-{{- if semverCompare ">=1.16-0" .Capabilities.KubeVersion.GitVersion -}}
-apiVersion: admissionregistration.k8s.io/v1
-{{- else -}}
 apiVersion: admissionregistration.k8s.io/v1beta1
-{{- end }}
 kind: ValidatingWebhookConfiguration
 metadata:
   creationTimestamp: null

charts/actions-runner-controller/values.yaml

@@ -100,6 +100,13 @@ env:
   # https_proxy: "proxy.com:8080"
   # no_proxy: ""
 
+scope:
+  # If true, the controller will only watch custom resources in a single namespace
+  singleNamespace: false
+  # If `scope.singleNamespace=true`, the controller will only watch custom resources in this namespace
+  # The default value is "", which means the namespace of the controller
+  watchNamespace: ""
+
 githubWebhookServer:
   enabled: false
   labels: {}

cmd/githubwebhookserver/main.go

@@ -110,7 +110,7 @@ func main() {
 		Recorder:       nil,
 		Scheme:         mgr.GetScheme(),
 		SecretKeyBytes: []byte(webhookSecretToken),
-		WatchNamespace: watchNamespace,
+		Namespace:      watchNamespace,
 	}
 
 	if err = hraGitHubWebhook.SetupWithManager(mgr); err != nil {

config/crd/bases/actions.summerwind.dev_horizontalrunnerautoscalers.yaml

@@ -148,6 +148,17 @@ spec:
                       checkRun:
                         description: https://docs.github.com/en/actions/reference/events-that-trigger-workflows#check_run
                         properties:
+                          names:
+                            description: Names is a list of GitHub Actions glob patterns.
+                              Any check_run event whose name matches one of patterns
+                              in the list can trigger autoscaling. Note that check_run
+                              name seem to equal to the job name you've defined in
+                              your actions workflow yaml file. So it is very likely
+                              that you can utilize this to trigger depending on the
+                              job.
+                            items:
+                              type: string
+                            type: array
                           status:
                             type: string
                           types:
@@ -196,6 +207,7 @@ spec:
               type: integer
             lastSuccessfulScaleOutTime:
               format: date-time
+              nullable: true
               type: string
             observedGeneration:
               description: ObservedGeneration is the most recent generation observed

config/crd/bases/actions.summerwind.dev_runnerdeployments.yaml

@@ -38,11 +38,42 @@ spec:
         metadata:
           type: object
         spec:
-          description: RunnerReplicaSetSpec defines the desired state of RunnerDeployment
+          description: RunnerDeploymentSpec defines the desired state of RunnerDeployment
           properties:
             replicas:
               nullable: true
               type: integer
+            selector:
+              description: A label selector is a label query over a set of resources. The result of matchLabels and matchExpressions are ANDed. An empty label selector matches all objects. A null label selector matches no objects.
+              nullable: true
+              properties:
+                matchExpressions:
+                  description: matchExpressions is a list of label selector requirements. The requirements are ANDed.
+                  items:
+                    description: A label selector requirement is a selector that contains values, a key, and an operator that relates the key and values.
+                    properties:
+                      key:
+                        description: key is the label key that the selector applies to.
+                        type: string
+                      operator:
+                        description: operator represents a key's relationship to a set of values. Valid operators are In, NotIn, Exists and DoesNotExist.
+                        type: string
+                      values:
+                        description: values is an array of string values. If the operator is In or NotIn, the values array must be non-empty. If the operator is Exists or DoesNotExist, the values array must be empty. This array is replaced during a strategic merge patch.
+                        items:
+                          type: string
+                        type: array
+                    required:
+                      - key
+                      - operator
+                    type: object
+                  type: array
+                matchLabels:
+                  additionalProperties:
+                    type: string
+                  description: matchLabels is a map of {key,value} pairs. A single {key,value} in the matchLabels map is equivalent to an element of matchExpressions, whose key field is "key", the operator is "In", and the values array contains only "value". The requirements are ANDed.
+                  type: object
+              type: object
             template:
               properties:
                 metadata:
@@ -402,6 +433,9 @@ spec:
                       type: array
                     dockerEnabled:
                       type: boolean
+                    dockerMTU:
+                      format: int64
+                      type: integer
                     dockerdContainerResources:
                       description: ResourceRequirements describes the compute resource requirements.
                       properties:

config/crd/bases/actions.summerwind.dev_runnerreplicasets.yaml

@@ -43,6 +43,37 @@ spec:
             replicas:
               nullable: true
               type: integer
+            selector:
+              description: A label selector is a label query over a set of resources. The result of matchLabels and matchExpressions are ANDed. An empty label selector matches all objects. A null label selector matches no objects.
+              nullable: true
+              properties:
+                matchExpressions:
+                  description: matchExpressions is a list of label selector requirements. The requirements are ANDed.
+                  items:
+                    description: A label selector requirement is a selector that contains values, a key, and an operator that relates the key and values.
+                    properties:
+                      key:
+                        description: key is the label key that the selector applies to.
+                        type: string
+                      operator:
+                        description: operator represents a key's relationship to a set of values. Valid operators are In, NotIn, Exists and DoesNotExist.
+                        type: string
+                      values:
+                        description: values is an array of string values. If the operator is In or NotIn, the values array must be non-empty. If the operator is Exists or DoesNotExist, the values array must be empty. This array is replaced during a strategic merge patch.
+                        items:
+                          type: string
+                        type: array
+                    required:
+                      - key
+                      - operator
+                    type: object
+                  type: array
+                matchLabels:
+                  additionalProperties:
+                    type: string
+                  description: matchLabels is a map of {key,value} pairs. A single {key,value} in the matchLabels map is equivalent to an element of matchExpressions, whose key field is "key", the operator is "In", and the values array contains only "value". The requirements are ANDed.
+                  type: object
+              type: object
             template:
               properties:
                 metadata:
@@ -402,6 +433,9 @@ spec:
                       type: array
                     dockerEnabled:
                       type: boolean
+                    dockerMTU:
+                      format: int64
+                      type: integer
                     dockerdContainerResources:
                       description: ResourceRequirements describes the compute resource requirements.
                       properties:

config/crd/bases/actions.summerwind.dev_runners.yaml

@@ -398,6 +398,9 @@ spec:
               type: array
             dockerEnabled:
               type: boolean
+            dockerMTU:
+              format: int64
+              type: integer
             dockerdContainerResources:
               description: ResourceRequirements describes the compute resource requirements.
               properties:
@@ -1538,6 +1541,10 @@ spec:
         status:
           description: RunnerStatus defines the observed state of Runner
           properties:
+            lastRegistrationCheckTime:
+              format: date-time
+              nullable: true
+              type: string
             message:
               type: string
             phase:
@@ -1566,11 +1573,6 @@ spec:
                 - expiresAt
                 - token
               type: object
-          required:
-            - message
-            - phase
-            - reason
-            - registration
           type: object
       type: object
   version: v1alpha1

controllers/autoscaling.go

@@ -10,6 +10,8 @@ import (
 	"time"
 
 	"github.com/summerwind/actions-runner-controller/api/v1alpha1"
+	kerrors "k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"sigs.k8s.io/controller-runtime/pkg/client"
 )
 
@@ -32,7 +34,7 @@ func getValueAvailableAt(now time.Time, from, to *time.Time, reservedValue int)
 	return &reservedValue
 }
 
-func (r *HorizontalRunnerAutoscalerReconciler) getDesiredReplicasFromCache(hra v1alpha1.HorizontalRunnerAutoscaler) *int {
+func (r *HorizontalRunnerAutoscalerReconciler) fetchSuggestedReplicasFromCache(hra v1alpha1.HorizontalRunnerAutoscaler) *int {
 	var entry *v1alpha1.CacheEntry
 
 	for i := range hra.Status.CacheEntries {
@@ -61,7 +63,7 @@ func (r *HorizontalRunnerAutoscalerReconciler) getDesiredReplicasFromCache(hra v
 	return nil
 }
 
-func (r *HorizontalRunnerAutoscalerReconciler) determineDesiredReplicas(rd v1alpha1.RunnerDeployment, hra v1alpha1.HorizontalRunnerAutoscaler) (*int, error) {
+func (r *HorizontalRunnerAutoscalerReconciler) suggestDesiredReplicas(rd v1alpha1.RunnerDeployment, hra v1alpha1.HorizontalRunnerAutoscaler) (*int, error) {
 	if hra.Spec.MinReplicas == nil {
 		return nil, fmt.Errorf("horizontalrunnerautoscaler %s/%s is missing minReplicas", hra.Namespace, hra.Name)
 	} else if hra.Spec.MaxReplicas == nil {
@@ -69,16 +71,22 @@ func (r *HorizontalRunnerAutoscalerReconciler) determineDesiredReplicas(rd v1alp
 	}
 
 	metrics := hra.Spec.Metrics
-	if len(metrics) == 0 || metrics[0].Type == v1alpha1.AutoscalingMetricTypeTotalNumberOfQueuedAndInProgressWorkflowRuns {
-		return r.calculateReplicasByQueuedAndInProgressWorkflowRuns(rd, hra)
+	if len(metrics) == 0 {
+		if len(hra.Spec.ScaleUpTriggers) == 0 {
+			return r.suggestReplicasByQueuedAndInProgressWorkflowRuns(rd, hra)
+		}
+
+		return nil, nil
+	} else if metrics[0].Type == v1alpha1.AutoscalingMetricTypeTotalNumberOfQueuedAndInProgressWorkflowRuns {
+		return r.suggestReplicasByQueuedAndInProgressWorkflowRuns(rd, hra)
 	} else if metrics[0].Type == v1alpha1.AutoscalingMetricTypePercentageRunnersBusy {
-		return r.calculateReplicasByPercentageRunnersBusy(rd, hra)
+		return r.suggestReplicasByPercentageRunnersBusy(rd, hra)
 	} else {
 		return nil, fmt.Errorf("validting autoscaling metrics: unsupported metric type %q", metrics[0].Type)
 	}
 }
 
-func (r *HorizontalRunnerAutoscalerReconciler) calculateReplicasByQueuedAndInProgressWorkflowRuns(rd v1alpha1.RunnerDeployment, hra v1alpha1.HorizontalRunnerAutoscaler) (*int, error) {
+func (r *HorizontalRunnerAutoscalerReconciler) suggestReplicasByQueuedAndInProgressWorkflowRuns(rd v1alpha1.RunnerDeployment, hra v1alpha1.HorizontalRunnerAutoscaler) (*int, error) {
 
 	var repos [][]string
 	metrics := hra.Spec.Metrics
@@ -89,6 +97,13 @@ func (r *HorizontalRunnerAutoscalerReconciler) calculateReplicasByQueuedAndInPro
 			return nil, fmt.Errorf("asserting runner deployment spec to detect bug: spec.template.organization should not be empty on this code path")
 		}
 
+		// In case it's an organizational runners deployment without any scaling metrics defined,
+		// we assume that the desired replicas should always be `minReplicas + capacityReservedThroughWebhook`.
+		// See https://github.com/summerwind/actions-runner-controller/issues/377#issuecomment-793372693
+		if len(metrics) == 0 {
+			return nil, nil
+		}
+
 		if len(metrics[0].RepositoryNames) == 0 {
 			return nil, errors.New("validating autoscaling metrics: spec.autoscaling.metrics[].repositoryNames is required and must have one more more entries for organizational runner deployment")
 		}
@@ -163,28 +178,10 @@ func (r *HorizontalRunnerAutoscalerReconciler) calculateReplicasByQueuedAndInPro
 		}
 	}
 
-	minReplicas := *hra.Spec.MinReplicas
-	maxReplicas := *hra.Spec.MaxReplicas
 	necessaryReplicas := queued + inProgress
 
-	var desiredReplicas int
-
-	if necessaryReplicas < minReplicas {
-		desiredReplicas = minReplicas
-	} else if necessaryReplicas > maxReplicas {
-		desiredReplicas = maxReplicas
-	} else {
-		desiredReplicas = necessaryReplicas
-	}
-
-	rd.Status.Replicas = &desiredReplicas
-	replicas := desiredReplicas
-
 	r.Log.V(1).Info(
-		"Calculated desired replicas",
-		"computed_replicas_desired", desiredReplicas,
-		"spec_replicas_min", minReplicas,
-		"spec_replicas_max", maxReplicas,
+		fmt.Sprintf("Suggested desired replicas of %d by TotalNumberOfQueuedAndInProgressWorkflowRuns", necessaryReplicas),
 		"workflow_runs_completed", completed,
 		"workflow_runs_in_progress", inProgress,
 		"workflow_runs_queued", queued,
@@ -194,13 +191,11 @@ func (r *HorizontalRunnerAutoscalerReconciler) calculateReplicasByQueuedAndInPro
 		"horizontal_runner_autoscaler", hra.Name,
 	)
 
-	return &replicas, nil
+	return &necessaryReplicas, nil
 }
 
-func (r *HorizontalRunnerAutoscalerReconciler) calculateReplicasByPercentageRunnersBusy(rd v1alpha1.RunnerDeployment, hra v1alpha1.HorizontalRunnerAutoscaler) (*int, error) {
+func (r *HorizontalRunnerAutoscalerReconciler) suggestReplicasByPercentageRunnersBusy(rd v1alpha1.RunnerDeployment, hra v1alpha1.HorizontalRunnerAutoscaler) (*int, error) {
 	ctx := context.Background()
-	minReplicas := *hra.Spec.MinReplicas
-	maxReplicas := *hra.Spec.MaxReplicas
 	metrics := hra.Spec.Metrics[0]
 	scaleUpThreshold := defaultScaleUpThreshold
 	scaleDownThreshold := defaultScaleDownThreshold
@@ -259,9 +254,30 @@ func (r *HorizontalRunnerAutoscalerReconciler) calculateReplicasByPercentageRunn
 
 	// return the list of runners in namespace. Horizontal Runner Autoscaler should only be responsible for scaling resources in its own ns.
 	var runnerList v1alpha1.RunnerList
-	if err := r.List(ctx, &runnerList, client.InNamespace(rd.Namespace)); err != nil {
+
+	var opts []client.ListOption
+
+	opts = append(opts, client.InNamespace(rd.Namespace))
+
+	selector, err := metav1.LabelSelectorAsSelector(getSelector(&rd))
+	if err != nil {
 		return nil, err
 	}
+
+	opts = append(opts, client.MatchingLabelsSelector{Selector: selector})
+
+	r.Log.V(2).Info("Finding runners with selector", "ns", rd.Namespace)
+
+	if err := r.List(
+		ctx,
+		&runnerList,
+		opts...,
+	); err != nil {
+		if !kerrors.IsNotFound(err) {
+			return nil, err
+		}
+	}
+
 	runnerMap := make(map[string]struct{})
 	for _, items := range runnerList.Items {
 		runnerMap[items.Name] = struct{}{}
@@ -282,45 +298,62 @@ func (r *HorizontalRunnerAutoscalerReconciler) calculateReplicasByPercentageRunn
 	if err != nil {
 		return nil, err
 	}
-	numRunners := len(runnerList.Items)
-	numRunnersBusy := 0
+
+	var desiredReplicasBefore int
+
+	if v := rd.Spec.Replicas; v == nil {
+		desiredReplicasBefore = 1
+	} else {
+		desiredReplicasBefore = *v
+	}
+
+	var (
+		numRunners           int
+		numRunnersRegistered int
+		numRunnersBusy       int
+	)
+
+	numRunners = len(runnerList.Items)
+
 	for _, runner := range runners {
-		if _, ok := runnerMap[*runner.Name]; ok && runner.GetBusy() {
+		if _, ok := runnerMap[*runner.Name]; ok {
+			numRunnersRegistered++
+
+			if runner.GetBusy() {
 				numRunnersBusy++
 			}
 		}
+	}
 
 	var desiredReplicas int
-	fractionBusy := float64(numRunnersBusy) / float64(numRunners)
+	fractionBusy := float64(numRunnersBusy) / float64(desiredReplicasBefore)
 	if fractionBusy >= scaleUpThreshold {
 		if scaleUpAdjustment > 0 {
-			desiredReplicas = numRunners + scaleUpAdjustment
+			desiredReplicas = desiredReplicasBefore + scaleUpAdjustment
 		} else {
-			desiredReplicas = int(math.Ceil(float64(numRunners) * scaleUpFactor))
+			desiredReplicas = int(math.Ceil(float64(desiredReplicasBefore) * scaleUpFactor))
 		}
 	} else if fractionBusy < scaleDownThreshold {
 		if scaleDownAdjustment > 0 {
-			desiredReplicas = numRunners - scaleDownAdjustment
+			desiredReplicas = desiredReplicasBefore - scaleDownAdjustment
 		} else {
-			desiredReplicas = int(float64(numRunners) * scaleDownFactor)
+			desiredReplicas = int(float64(desiredReplicasBefore) * scaleDownFactor)
 		}
 	} else {
 		desiredReplicas = *rd.Spec.Replicas
 	}
 
-	if desiredReplicas < minReplicas {
-		desiredReplicas = minReplicas
-	} else if desiredReplicas > maxReplicas {
-		desiredReplicas = maxReplicas
-	}
+	// NOTES for operators:
+	//
+	// - num_runners can be as twice as large as replicas_desired_before while
+	//   the runnerdeployment controller is replacing RunnerReplicaSet for runner update.
 
 	r.Log.V(1).Info(
-		"Calculated desired replicas",
-		"computed_replicas_desired", desiredReplicas,
-		"spec_replicas_min", minReplicas,
-		"spec_replicas_max", maxReplicas,
-		"current_replicas", rd.Spec.Replicas,
+		fmt.Sprintf("Suggested desired replicas of %d by PercentageRunnersBusy", desiredReplicas),
+		"replicas_desired_before", desiredReplicasBefore,
+		"replicas_desired", desiredReplicas,
 		"num_runners", numRunners,
+		"num_runners_registered", numRunnersRegistered,
 		"num_runners_busy", numRunnersBusy,
 		"namespace", hra.Namespace,
 		"runner_deployment", rd.Name,
@@ -330,8 +363,5 @@ func (r *HorizontalRunnerAutoscalerReconciler) calculateReplicasByPercentageRunn
 		"repository", repository,
 	)
 
-	rd.Status.Replicas = &desiredReplicas
-	replicas := desiredReplicas
-
-	return &replicas, nil
+	return &desiredReplicas, nil
 }

controllers/autoscaling_test.go

@@ -224,7 +224,7 @@ func TestDetermineDesiredReplicas_RepositoryRunner(t *testing.T) {
 				},
 			}
 
-			got, err := h.computeReplicas(rd, hra)
+			got, _, _, err := h.computeReplicasWithCache(log, metav1Now.Time, rd, hra)
 			if err != nil {
 				if tc.err == "" {
 					t.Fatalf("unexpected error: expected none, got %v", err)
@@ -234,12 +234,8 @@ func TestDetermineDesiredReplicas_RepositoryRunner(t *testing.T) {
 				return
 			}
 
-			if got == nil {
-				t.Fatalf("unexpected value of rs.Spec.Replicas: nil")
-			}
-
-			if *got != tc.want {
-				t.Errorf("%d: incorrect desired replicas: want %d, got %d", i, tc.want, *got)
+			if got != tc.want {
+				t.Errorf("%d: incorrect desired replicas: want %d, got %d", i, tc.want, got)
 			}
 		})
 	}
@@ -424,6 +420,8 @@ func TestDetermineDesiredReplicas_OrganizationalRunner(t *testing.T) {
 		_ = v1alpha1.AddToScheme(scheme)
 
 		t.Run(fmt.Sprintf("case %d", i), func(t *testing.T) {
+			t.Helper()
+
 			server := fake.NewServer(
 				fake.WithListRepositoryWorkflowRunsResponse(200, tc.workflowRuns, tc.workflowRuns_queued, tc.workflowRuns_in_progress),
 				fake.WithListWorkflowJobsResponse(200, tc.workflowJobs),
@@ -443,7 +441,17 @@ func TestDetermineDesiredReplicas_OrganizationalRunner(t *testing.T) {
 					Name: "testrd",
 				},
 				Spec: v1alpha1.RunnerDeploymentSpec{
+					Selector: &metav1.LabelSelector{
+						MatchLabels: map[string]string{
+							"foo": "bar",
+						},
+					},
 					Template: v1alpha1.RunnerTemplate{
+						ObjectMeta: metav1.ObjectMeta{
+							Labels: map[string]string{
+								"foo": "bar",
+							},
+						},
 						Spec: v1alpha1.RunnerSpec{
 							Organization: tc.org,
 						},
@@ -475,7 +483,7 @@ func TestDetermineDesiredReplicas_OrganizationalRunner(t *testing.T) {
 				},
 			}
 
-			got, err := h.computeReplicas(rd, hra)
+			got, _, _, err := h.computeReplicasWithCache(log, metav1Now.Time, rd, hra)
 			if err != nil {
 				if tc.err == "" {
 					t.Fatalf("unexpected error: expected none, got %v", err)
@@ -485,12 +493,8 @@ func TestDetermineDesiredReplicas_OrganizationalRunner(t *testing.T) {
 				return
 			}
 
-			if got == nil {
-				t.Fatalf("unexpected value of rs.Spec.Replicas: nil, wanted %v", tc.want)
-			}
-
-			if *got != tc.want {
-				t.Errorf("%d: incorrect desired replicas: want %d, got %d", i, tc.want, *got)
+			if got != tc.want {
+				t.Errorf("%d: incorrect desired replicas: want %d, got %d", i, tc.want, got)
 			}
 		})
 	}

controllers/horizontal_runner_autoscaler_webhook.go

@@ -53,10 +53,10 @@ type HorizontalRunnerAutoscalerGitHubWebhook struct {
 	// the administrator is generated and specified in GitHub Web UI.
 	SecretKeyBytes []byte
 
-	// WatchNamespace is the namespace to watch for HorizontalRunnerAutoscaler's to be
+	// Namespace is the namespace to watch for HorizontalRunnerAutoscaler's to be
 	// scaled on Webhook.
 	// Set to empty for letting it watch for all namespaces.
-	WatchNamespace string
+	Namespace string
 	Name      string
 }
 
@@ -95,6 +95,12 @@ func (autoscaler *HorizontalRunnerAutoscalerGitHubWebhook) Handle(w http.Respons
 		}
 	}()
 
+	// respond ok to GET / e.g. for health check
+	if r.Method == http.MethodGet {
+		fmt.Fprintln(w, "webhook server is running")
+		return
+	}
+
 	var payload []byte
 
 	if len(autoscaler.SecretKeyBytes) > 0 {
@@ -153,6 +159,13 @@ func (autoscaler *HorizontalRunnerAutoscalerGitHubWebhook) Handle(w http.Respons
 			e.Repo.Owner.GetType(),
 			autoscaler.MatchPullRequestEvent(e),
 		)
+
+		if pullRequest := e.PullRequest; pullRequest != nil {
+			log = log.WithValues(
+				"pullRequest.base.ref", e.PullRequest.Base.GetRef(),
+				"action", e.GetAction(),
+			)
+		}
 	case *gogithub.CheckRunEvent:
 		target, err = autoscaler.getScaleUpTarget(
 			context.TODO(),
@@ -162,6 +175,13 @@ func (autoscaler *HorizontalRunnerAutoscalerGitHubWebhook) Handle(w http.Respons
 			e.Repo.Owner.GetType(),
 			autoscaler.MatchCheckRunEvent(e),
 		)
+
+		if checkRun := e.GetCheckRun(); checkRun != nil {
+			log = log.WithValues(
+				"checkRun.status", checkRun.GetStatus(),
+				"action", e.GetAction(),
+			)
+		}
 	case *gogithub.PingEvent:
 		ok = true
 
@@ -189,9 +209,11 @@ func (autoscaler *HorizontalRunnerAutoscalerGitHubWebhook) Handle(w http.Respons
 	}
 
 	if target == nil {
-		msg := "no horizontalrunnerautoscaler to scale for this github event"
+		log.Info(
+			"Scale target not found. If this is unexpected, ensure that there is exactly one repository-wide or organizational runner deployment that matches this webhook event",
+		)
 
-		log.Info(msg, "eventType", webhookType)
+		msg := "no horizontalrunnerautoscaler to scale for this github event"
 
 		ok = true
 
@@ -224,7 +246,7 @@ func (autoscaler *HorizontalRunnerAutoscalerGitHubWebhook) Handle(w http.Respons
 }
 
 func (autoscaler *HorizontalRunnerAutoscalerGitHubWebhook) findHRAsByKey(ctx context.Context, value string) ([]v1alpha1.HorizontalRunnerAutoscaler, error) {
-	ns := autoscaler.WatchNamespace
+	ns := autoscaler.Namespace
 
 	var defaultListOpts []client.ListOption
 
@@ -238,8 +260,8 @@ func (autoscaler *HorizontalRunnerAutoscalerGitHubWebhook) findHRAsByKey(ctx con
 		opts := append([]client.ListOption{}, defaultListOpts...)
 		opts = append(opts, client.MatchingFields{scaleTargetKey: value})
 
-		if autoscaler.WatchNamespace != "" {
-			opts = append(opts, client.InNamespace(autoscaler.WatchNamespace))
+		if autoscaler.Namespace != "" {
+			opts = append(opts, client.InNamespace(autoscaler.Namespace))
 		}
 
 		var hraList v1alpha1.HorizontalRunnerAutoscalerList
@@ -326,7 +348,7 @@ func (autoscaler *HorizontalRunnerAutoscalerGitHubWebhook) getScaleTarget(ctx co
 		autoscaler.Log.Info(
 			"Found too many scale targets: "+
 				"It must be exactly one to avoid ambiguity. "+
-				"Either set WatchNamespace for the webhook-based autoscaler to let it only find HRAs in the namespace, "+
+				"Either set Namespace for the webhook-based autoscaler to let it only find HRAs in the namespace, "+
 				"or update Repository or Organization fields in your RunnerDeployment resources to fix the ambiguity.",
 			"scaleTargets", strings.Join(scaleTargetIDs, ","))
 
@@ -359,10 +381,6 @@ func (autoscaler *HorizontalRunnerAutoscalerGitHubWebhook) getScaleUpTarget(ctx
 		return target, nil
 	}
 
-	log.Info(
-		"Scale target not found. If this is unexpected, ensure that there is exactly one repository-wide or organizational runner deployment that matches this webhook event",
-	)
-
 	return nil, nil
 }
 
@@ -371,8 +389,6 @@ func (autoscaler *HorizontalRunnerAutoscalerGitHubWebhook) tryScaleUp(ctx contex
 		return nil
 	}
 
-	log := autoscaler.Log.WithValues("horizontalrunnerautoscaler", target.HorizontalRunnerAutoscaler.Name)
-
 	copy := target.HorizontalRunnerAutoscaler.DeepCopy()
 
 	amount := 1
@@ -388,10 +404,8 @@ func (autoscaler *HorizontalRunnerAutoscalerGitHubWebhook) tryScaleUp(ctx contex
 		Replicas:       amount,
 	})
 
-	if err := autoscaler.Client.Update(ctx, copy); err != nil {
-		log.Error(err, "Failed to update horizontalrunnerautoscaler resource")
-
-		return err
+	if err := autoscaler.Client.Patch(ctx, copy, client.MergeFrom(&target.HorizontalRunnerAutoscaler)); err != nil {
+		return fmt.Errorf("patching horizontalrunnerautoscaler to add capacity reservation: %w", err)
 	}
 
 	return nil

controllers/horizontal_runner_autoscaler_webhook_on_check_run.go

@@ -3,6 +3,7 @@ package controllers
 import (
 	"github.com/google/go-github/v33/github"
 	"github.com/summerwind/actions-runner-controller/api/v1alpha1"
+	"github.com/summerwind/actions-runner-controller/pkg/actionsglob"
 )
 
 func (autoscaler *HorizontalRunnerAutoscalerGitHubWebhook) MatchCheckRunEvent(event *github.CheckRunEvent) func(scaleUpTrigger v1alpha1.ScaleUpTrigger) bool {
@@ -27,6 +28,16 @@ func (autoscaler *HorizontalRunnerAutoscalerGitHubWebhook) MatchCheckRunEvent(ev
 			return false
 		}
 
+		if checkRun := event.CheckRun; checkRun != nil && len(cr.Names) > 0 {
+			for _, pat := range cr.Names {
+				if r := actionsglob.Match(pat, checkRun.GetName()); r {
+					return true
+				}
+			}
+
+			return false
+		}
+
 		return true
 	}
 }

controllers/horizontal_runner_autoscaler_webhook_test.go

@@ -113,6 +113,19 @@ func TestWebhookPing(t *testing.T) {
 	)
 }
 
+func TestGetRequest(t *testing.T) {
+	hra := HorizontalRunnerAutoscalerGitHubWebhook{}
+	request, _ := http.NewRequest(http.MethodGet, "/", nil)
+	recorder := httptest.ResponseRecorder{}
+
+	hra.Handle(&recorder, request)
+	response := recorder.Result()
+
+	if response.StatusCode != http.StatusOK {
+		t.Errorf("want %d, got %d", http.StatusOK, response.StatusCode)
+	}
+}
+
 func TestGetValidCapacityReservations(t *testing.T) {
 	now := time.Now()
 

controllers/horizontalrunnerautoscaler_controller.go

@@ -18,6 +18,8 @@ package controllers
 
 import (
 	"context"
+	"fmt"
+	corev1 "k8s.io/api/core/v1"
 	"time"
 
 	"github.com/summerwind/actions-runner-controller/github"
@@ -29,10 +31,10 @@ import (
 	ctrl "sigs.k8s.io/controller-runtime"
 	"sigs.k8s.io/controller-runtime/pkg/client"
 
-	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 
 	"github.com/summerwind/actions-runner-controller/api/v1alpha1"
+	"github.com/summerwind/actions-runner-controller/controllers/metrics"
 )
 
 const (
@@ -51,6 +53,8 @@ type HorizontalRunnerAutoscalerReconciler struct {
 	Name          string
 }
 
+const defaultReplicas = 1
+
 // +kubebuilder:rbac:groups=actions.summerwind.dev,resources=runnerdeployments,verbs=get;list;watch;update;patch
 // +kubebuilder:rbac:groups=actions.summerwind.dev,resources=horizontalrunnerautoscalers,verbs=get;list;watch;create;update;patch;delete
 // +kubebuilder:rbac:groups=actions.summerwind.dev,resources=horizontalrunnerautoscalers/finalizers,verbs=get;list;watch;create;update;patch;delete
@@ -70,6 +74,8 @@ func (r *HorizontalRunnerAutoscalerReconciler) Reconcile(req ctrl.Request) (ctrl
 		return ctrl.Result{}, nil
 	}
 
+	metrics.SetHorizontalRunnerAutoscalerSpec(hra.ObjectMeta, hra.Spec)
+
 	var rd v1alpha1.RunnerDeployment
 	if err := r.Get(ctx, types.NamespacedName{
 		Namespace: req.Namespace,
@@ -82,16 +88,9 @@ func (r *HorizontalRunnerAutoscalerReconciler) Reconcile(req ctrl.Request) (ctrl
 		return ctrl.Result{}, nil
 	}
 
-	var replicas *int
+	now := time.Now()
 
-	replicasFromCache := r.getDesiredReplicasFromCache(hra)
-
-	if replicasFromCache != nil {
-		replicas = replicasFromCache
-	} else {
-		var err error
-
-		replicas, err = r.computeReplicas(rd, hra)
+	newDesiredReplicas, computedReplicas, computedReplicasFromCache, err := r.computeReplicasWithCache(log, now, rd, hra)
 	if err != nil {
 		r.Recorder.Event(&hra, corev1.EventTypeNormal, "RunnerAutoscalingFailure", err.Error())
 
@@ -99,34 +98,16 @@ func (r *HorizontalRunnerAutoscalerReconciler) Reconcile(req ctrl.Request) (ctrl
 
 		return ctrl.Result{}, err
 	}
-	}
-
-	const defaultReplicas = 1
 
 	currentDesiredReplicas := getIntOrDefault(rd.Spec.Replicas, defaultReplicas)
-	newDesiredReplicas := getIntOrDefault(replicas, defaultReplicas)
-
-	now := time.Now()
-
-	for _, reservation := range hra.Spec.CapacityReservations {
-		if reservation.ExpirationTime.Time.After(now) {
-			newDesiredReplicas += reservation.Replicas
-		}
-	}
-
-	if hra.Spec.MaxReplicas != nil && *hra.Spec.MaxReplicas < newDesiredReplicas {
-		newDesiredReplicas = *hra.Spec.MaxReplicas
-	}
 
 	// Please add more conditions that we can in-place update the newest runnerreplicaset without disruption
 	if currentDesiredReplicas != newDesiredReplicas {
 		copy := rd.DeepCopy()
 		copy.Spec.Replicas = &newDesiredReplicas
 
-		if err := r.Client.Update(ctx, copy); err != nil {
-			log.Error(err, "Failed to update runnerderployment resource")
-
-			return ctrl.Result{}, err
+		if err := r.Client.Patch(ctx, copy, client.MergeFrom(&rd)); err != nil {
+			return ctrl.Result{}, fmt.Errorf("patching runnerdeployment to have %d replicas: %w", newDesiredReplicas, err)
 		}
 	}
 
@@ -144,18 +125,12 @@ func (r *HorizontalRunnerAutoscalerReconciler) Reconcile(req ctrl.Request) (ctrl
 		updated.Status.DesiredReplicas = &newDesiredReplicas
 	}
 
-	if replicasFromCache == nil {
+	if computedReplicasFromCache == nil {
 		if updated == nil {
 			updated = hra.DeepCopy()
 		}
 
-		var cacheEntries []v1alpha1.CacheEntry
-
-		for _, ent := range updated.Status.CacheEntries {
-			if ent.ExpirationTime.Before(&metav1.Time{Time: now}) {
-				cacheEntries = append(cacheEntries, ent)
-			}
-		}
+		cacheEntries := getValidCacheEntries(updated, now)
 
 		var cacheDuration time.Duration
 
@@ -167,22 +142,34 @@ func (r *HorizontalRunnerAutoscalerReconciler) Reconcile(req ctrl.Request) (ctrl
 
 		updated.Status.CacheEntries = append(cacheEntries, v1alpha1.CacheEntry{
 			Key:            v1alpha1.CacheEntryKeyDesiredReplicas,
-			Value:          *replicas,
+			Value:          computedReplicas,
 			ExpirationTime: metav1.Time{Time: time.Now().Add(cacheDuration)},
 		})
 	}
 
 	if updated != nil {
-		if err := r.Status().Update(ctx, updated); err != nil {
-			log.Error(err, "Failed to update horizontalrunnerautoscaler status")
+		metrics.SetHorizontalRunnerAutoscalerStatus(updated.ObjectMeta, updated.Status)
 
-			return ctrl.Result{}, err
+		if err := r.Status().Patch(ctx, updated, client.MergeFrom(&hra)); err != nil {
+			return ctrl.Result{}, fmt.Errorf("patching horizontalrunnerautoscaler status to add cache entry: %w", err)
 		}
 	}
 
 	return ctrl.Result{}, nil
 }
 
+func getValidCacheEntries(hra *v1alpha1.HorizontalRunnerAutoscaler, now time.Time) []v1alpha1.CacheEntry {
+	var cacheEntries []v1alpha1.CacheEntry
+
+	for _, ent := range hra.Status.CacheEntries {
+		if ent.ExpirationTime.After(now) {
+			cacheEntries = append(cacheEntries, ent)
+		}
+	}
+
+	return cacheEntries
+}
+
 func (r *HorizontalRunnerAutoscalerReconciler) SetupWithManager(mgr ctrl.Manager) error {
 	name := "horizontalrunnerautoscaler-controller"
 	if r.Name != "" {
@@ -197,14 +184,59 @@ func (r *HorizontalRunnerAutoscalerReconciler) SetupWithManager(mgr ctrl.Manager
 		Complete(r)
 }
 
-func (r *HorizontalRunnerAutoscalerReconciler) computeReplicas(rd v1alpha1.RunnerDeployment, hra v1alpha1.HorizontalRunnerAutoscaler) (*int, error) {
-	var computedReplicas *int
-
-	replicas, err := r.determineDesiredReplicas(rd, hra)
-	if err != nil {
-		return nil, err
+func (r *HorizontalRunnerAutoscalerReconciler) computeReplicasWithCache(log logr.Logger, now time.Time, rd v1alpha1.RunnerDeployment, hra v1alpha1.HorizontalRunnerAutoscaler) (int, int, *int, error) {
+	minReplicas := defaultReplicas
+	if hra.Spec.MinReplicas != nil && *hra.Spec.MinReplicas > 0 {
+		minReplicas = *hra.Spec.MinReplicas
 	}
 
+	var suggestedReplicas int
+
+	suggestedReplicasFromCache := r.fetchSuggestedReplicasFromCache(hra)
+
+	var cached *int
+
+	if suggestedReplicasFromCache != nil {
+		cached = suggestedReplicasFromCache
+
+		if cached == nil {
+			suggestedReplicas = minReplicas
+		} else {
+			suggestedReplicas = *cached
+		}
+	} else {
+		v, err := r.suggestDesiredReplicas(rd, hra)
+		if err != nil {
+			return 0, 0, nil, err
+		}
+
+		if v == nil {
+			suggestedReplicas = minReplicas
+		} else {
+			suggestedReplicas = *v
+		}
+	}
+
+	var reserved int
+
+	for _, reservation := range hra.Spec.CapacityReservations {
+		if reservation.ExpirationTime.Time.After(now) {
+			reserved += reservation.Replicas
+		}
+	}
+
+	newDesiredReplicas := suggestedReplicas + reserved
+
+	if newDesiredReplicas < minReplicas {
+		newDesiredReplicas = minReplicas
+	} else if hra.Spec.MaxReplicas != nil && newDesiredReplicas > *hra.Spec.MaxReplicas {
+		newDesiredReplicas = *hra.Spec.MaxReplicas
+	}
+
+	//
+	// Delay scaling-down for ScaleDownDelaySecondsAfterScaleUp or DefaultScaleDownDelay
+	//
+
 	var scaleDownDelay time.Duration
 
 	if hra.Spec.ScaleDownDelaySecondsAfterScaleUp != nil {
@@ -213,17 +245,50 @@ func (r *HorizontalRunnerAutoscalerReconciler) computeReplicas(rd v1alpha1.Runne
 		scaleDownDelay = DefaultScaleDownDelay
 	}
 
-	now := time.Now()
+	var scaleDownDelayUntil *time.Time
 
 	if hra.Status.DesiredReplicas == nil ||
-		*hra.Status.DesiredReplicas < *replicas ||
-		hra.Status.LastSuccessfulScaleOutTime == nil ||
-		hra.Status.LastSuccessfulScaleOutTime.Add(scaleDownDelay).Before(now) {
+		*hra.Status.DesiredReplicas < newDesiredReplicas ||
+		hra.Status.LastSuccessfulScaleOutTime == nil {
 
-		computedReplicas = replicas
+	} else if hra.Status.LastSuccessfulScaleOutTime != nil {
+		t := hra.Status.LastSuccessfulScaleOutTime.Add(scaleDownDelay)
+
+		// ScaleDownDelay is not passed
+		if t.After(now) {
+			scaleDownDelayUntil = &t
+			newDesiredReplicas = *hra.Status.DesiredReplicas
+		}
 	} else {
-		computedReplicas = hra.Status.DesiredReplicas
+		newDesiredReplicas = *hra.Status.DesiredReplicas
 	}
 
-	return computedReplicas, nil
+	//
+	// Logs various numbers for monitoring and debugging purpose
+	//
+
+	kvs := []interface{}{
+		"suggested", suggestedReplicas,
+		"reserved", reserved,
+		"min", minReplicas,
+	}
+
+	if cached != nil {
+		kvs = append(kvs, "cached", *cached)
+	}
+
+	if scaleDownDelayUntil != nil {
+		kvs = append(kvs, "last_scale_up_time", *hra.Status.LastSuccessfulScaleOutTime)
+		kvs = append(kvs, "scale_down_delay_until", scaleDownDelayUntil)
+	}
+
+	if maxReplicas := hra.Spec.MaxReplicas; maxReplicas != nil {
+		kvs = append(kvs, "max", *maxReplicas)
+	}
+
+	log.V(1).Info(fmt.Sprintf("Calculated desired replicas of %d", newDesiredReplicas),
+		kvs...,
+	)
+
+	return newDesiredReplicas, suggestedReplicas, suggestedReplicasFromCache, nil
 }

controllers/horizontalrunnerautoscaler_controller_test.go

@@ -0,0 +1,49 @@
+package controllers
+
+import (
+	"github.com/google/go-cmp/cmp"
+	actionsv1alpha1 "github.com/summerwind/actions-runner-controller/api/v1alpha1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"testing"
+	"time"
+)
+
+func TestGetValidCacheEntries(t *testing.T) {
+	now := time.Now()
+
+	hra := &actionsv1alpha1.HorizontalRunnerAutoscaler{
+		Status: actionsv1alpha1.HorizontalRunnerAutoscalerStatus{
+			CacheEntries: []actionsv1alpha1.CacheEntry{
+				{
+					Key:            "foo",
+					Value:          1,
+					ExpirationTime: metav1.Time{Time: now.Add(-time.Second)},
+				},
+				{
+					Key:            "foo",
+					Value:          2,
+					ExpirationTime: metav1.Time{Time: now},
+				},
+				{
+					Key:            "foo",
+					Value:          3,
+					ExpirationTime: metav1.Time{Time: now.Add(time.Second)},
+				},
+			},
+		},
+	}
+
+	revs := getValidCacheEntries(hra, now)
+
+	counts := map[string]int{}
+
+	for _, r := range revs {
+		counts[r.Key] += r.Value
+	}
+
+	want := map[string]int{"foo": 3}
+
+	if d := cmp.Diff(want, counts); d != "" {
+		t.Errorf("%s", d)
+	}
+}

controllers/integration_test.go

@@ -3,13 +3,14 @@ package controllers
 import (
 	"context"
 	"fmt"
-	"github.com/google/go-github/v33/github"
-	github2 "github.com/summerwind/actions-runner-controller/github"
-	"k8s.io/apimachinery/pkg/runtime"
 	"net/http"
 	"net/http/httptest"
 	"time"
 
+	"github.com/google/go-github/v33/github"
+	github2 "github.com/summerwind/actions-runner-controller/github"
+	"k8s.io/apimachinery/pkg/runtime"
+
 	"github.com/summerwind/actions-runner-controller/github/fake"
 
 	corev1 "k8s.io/api/core/v1"
@@ -70,7 +71,9 @@ func SetupIntegrationTest(ctx context.Context) *testEnvironment {
 		err := k8sClient.Create(ctx, ns)
 		Expect(err).NotTo(HaveOccurred(), "failed to create test namespace")
 
-		mgr, err := ctrl.NewManager(cfg, ctrl.Options{})
+		mgr, err := ctrl.NewManager(cfg, ctrl.Options{
+			Namespace: ns.Name,
+		})
 		Expect(err).NotTo(HaveOccurred(), "failed to create manager")
 
 		responses := &fake.FixedResponses{}
@@ -96,6 +99,21 @@ func SetupIntegrationTest(ctx context.Context) *testEnvironment {
 			return fmt.Sprintf("%s%s", ns.Name, name)
 		}
 
+		runnerController := &RunnerReconciler{
+			Client:                      mgr.GetClient(),
+			Scheme:                      scheme.Scheme,
+			Log:                         logf.Log,
+			Recorder:                    mgr.GetEventRecorderFor("runnerreplicaset-controller"),
+			GitHubClient:                env.ghClient,
+			RunnerImage:                 "example/runner:test",
+			DockerImage:                 "example/docker:test",
+			Name:                        controllerName("runner"),
+			RegistrationRecheckInterval: time.Millisecond,
+			RegistrationRecheckJitter:   time.Millisecond,
+		}
+		err = runnerController.SetupWithManager(mgr)
+		Expect(err).NotTo(HaveOccurred(), "failed to setup runner controller")
+
 		replicasetController := &RunnerReplicaSetReconciler{
 			Client:       mgr.GetClient(),
 			Scheme:       scheme.Scheme,
@@ -105,7 +123,7 @@ func SetupIntegrationTest(ctx context.Context) *testEnvironment {
 			Name:         controllerName("runnerreplicaset"),
 		}
 		err = replicasetController.SetupWithManager(mgr)
-		Expect(err).NotTo(HaveOccurred(), "failed to setup controller")
+		Expect(err).NotTo(HaveOccurred(), "failed to setup runnerreplicaset controller")
 
 		deploymentsController := &RunnerDeploymentReconciler{
 			Client:   mgr.GetClient(),
@@ -115,7 +133,7 @@ func SetupIntegrationTest(ctx context.Context) *testEnvironment {
 			Name:     controllerName("runnnerdeployment"),
 		}
 		err = deploymentsController.SetupWithManager(mgr)
-		Expect(err).NotTo(HaveOccurred(), "failed to setup controller")
+		Expect(err).NotTo(HaveOccurred(), "failed to setup runnerdeployment controller")
 
 		autoscalerController := &HorizontalRunnerAutoscalerReconciler{
 			Client:        mgr.GetClient(),
@@ -127,7 +145,7 @@ func SetupIntegrationTest(ctx context.Context) *testEnvironment {
 			Name:          controllerName("horizontalrunnerautoscaler"),
 		}
 		err = autoscalerController.SetupWithManager(mgr)
-		Expect(err).NotTo(HaveOccurred(), "failed to setup controller")
+		Expect(err).NotTo(HaveOccurred(), "failed to setup autoscaler controller")
 
 		autoscalerWebhook := &HorizontalRunnerAutoscalerGitHubWebhook{
 			Client:    mgr.GetClient(),
@@ -135,7 +153,7 @@ func SetupIntegrationTest(ctx context.Context) *testEnvironment {
 			Log:       logf.Log,
 			Recorder:  mgr.GetEventRecorderFor("horizontalrunnerautoscaler-controller"),
 			Name:      controllerName("horizontalrunnerautoscalergithubwebhook"),
-			WatchNamespace: ns.Name,
+			Namespace: ns.Name,
 		}
 		err = autoscalerWebhook.SetupWithManager(mgr)
 		Expect(err).NotTo(HaveOccurred(), "failed to setup autoscaler webhook")
@@ -173,6 +191,93 @@ var _ = Context("INTEGRATION: Inside of a new namespace", func() {
 
 	Describe("when no existing resources exist", func() {
 
+		It("should create and scale organizational runners without any scaling metrics on pull_request event", func() {
+			name := "example-runnerdeploy"
+
+			{
+				rd := &actionsv1alpha1.RunnerDeployment{
+					ObjectMeta: metav1.ObjectMeta{
+						Name:      name,
+						Namespace: ns.Name,
+					},
+					Spec: actionsv1alpha1.RunnerDeploymentSpec{
+						Replicas: intPtr(1),
+						Selector: &metav1.LabelSelector{
+							MatchLabels: map[string]string{
+								"foo": "bar",
+							},
+						},
+						Template: actionsv1alpha1.RunnerTemplate{
+							ObjectMeta: metav1.ObjectMeta{
+								Labels: map[string]string{
+									"foo": "bar",
+								},
+							},
+							Spec: actionsv1alpha1.RunnerSpec{
+								Organization: "test",
+								Image:        "bar",
+								Group:        "baz",
+								Env: []corev1.EnvVar{
+									{Name: "FOO", Value: "FOOVALUE"},
+								},
+							},
+						},
+					},
+				}
+
+				ExpectCreate(ctx, rd, "test RunnerDeployment")
+				ExpectRunnerSetsCountEventuallyEquals(ctx, ns.Name, 1)
+				ExpectRunnerSetsManagedReplicasCountEventuallyEquals(ctx, ns.Name, 1)
+			}
+
+			// Scale-up to 2 replicas
+			{
+				hra := &actionsv1alpha1.HorizontalRunnerAutoscaler{
+					ObjectMeta: metav1.ObjectMeta{
+						Name:      name,
+						Namespace: ns.Name,
+					},
+					Spec: actionsv1alpha1.HorizontalRunnerAutoscalerSpec{
+						ScaleTargetRef: actionsv1alpha1.ScaleTargetRef{
+							Name: name,
+						},
+						MinReplicas:                       intPtr(2),
+						MaxReplicas:                       intPtr(5),
+						ScaleDownDelaySecondsAfterScaleUp: intPtr(1),
+						Metrics:                           nil,
+						ScaleUpTriggers: []actionsv1alpha1.ScaleUpTrigger{
+							{
+								GitHubEvent: &actionsv1alpha1.GitHubEventScaleUpTriggerSpec{
+									PullRequest: &actionsv1alpha1.PullRequestSpec{
+										Types:    []string{"created"},
+										Branches: []string{"main"},
+									},
+								},
+								Amount:   1,
+								Duration: metav1.Duration{Duration: time.Minute},
+							},
+						},
+					},
+				}
+
+				ExpectCreate(ctx, hra, "test HorizontalRunnerAutoscaler")
+
+				ExpectRunnerSetsCountEventuallyEquals(ctx, ns.Name, 1)
+				ExpectRunnerSetsManagedReplicasCountEventuallyEquals(ctx, ns.Name, 2)
+				ExpectHRAStatusCacheEntryLengthEventuallyEquals(ctx, ns.Name, name, 1)
+			}
+
+			{
+				env.ExpectRegisteredNumberCountEventuallyEquals(2, "count of fake runners after HRA creation")
+			}
+
+			// Scale-up to 3 replicas on second pull_request create webhook event
+			{
+				env.SendOrgPullRequestEvent("test", "valid", "main", "created")
+				ExpectRunnerSetsManagedReplicasCountEventuallyEquals(ctx, ns.Name, 3, "runners after second webhook event")
+			}
+		})
+
 		It("should create and scale organization's repository runners on pull_request event", func() {
 			name := "example-runnerdeploy"
 
@@ -184,7 +289,17 @@ var _ = Context("INTEGRATION: Inside of a new namespace", func() {
 					},
 					Spec: actionsv1alpha1.RunnerDeploymentSpec{
 						Replicas: intPtr(1),
+						Selector: &metav1.LabelSelector{
+							MatchLabels: map[string]string{
+								"foo": "bar",
+							},
+						},
 						Template: actionsv1alpha1.RunnerTemplate{
+							ObjectMeta: metav1.ObjectMeta{
+								Labels: map[string]string{
+									"foo": "bar",
+								},
+							},
 							Spec: actionsv1alpha1.RunnerSpec{
 								Repository: "test/valid",
 								Image:      "bar",
@@ -224,7 +339,11 @@ var _ = Context("INTEGRATION: Inside of a new namespace", func() {
 						MinReplicas:                       intPtr(1),
 						MaxReplicas:                       intPtr(3),
 						ScaleDownDelaySecondsAfterScaleUp: intPtr(1),
-						Metrics:                           nil,
+						Metrics: []actionsv1alpha1.MetricSpec{
+							{
+								Type: actionsv1alpha1.AutoscalingMetricTypeTotalNumberOfQueuedAndInProgressWorkflowRuns,
+							},
+						},
 						ScaleUpTriggers: []actionsv1alpha1.ScaleUpTrigger{
 							{
 								GitHubEvent: &actionsv1alpha1.GitHubEventScaleUpTriggerSpec{
@@ -244,6 +363,7 @@ var _ = Context("INTEGRATION: Inside of a new namespace", func() {
 
 				ExpectRunnerSetsCountEventuallyEquals(ctx, ns.Name, 1)
 				ExpectRunnerSetsManagedReplicasCountEventuallyEquals(ctx, ns.Name, 3)
+				ExpectHRAStatusCacheEntryLengthEventuallyEquals(ctx, ns.Name, name, 1)
 			}
 
 			{
@@ -300,7 +420,17 @@ var _ = Context("INTEGRATION: Inside of a new namespace", func() {
 					},
 					Spec: actionsv1alpha1.RunnerDeploymentSpec{
 						Replicas: intPtr(1),
+						Selector: &metav1.LabelSelector{
+							MatchLabels: map[string]string{
+								"foo": "bar",
+							},
+						},
 						Template: actionsv1alpha1.RunnerTemplate{
+							ObjectMeta: metav1.ObjectMeta{
+								Labels: map[string]string{
+									"foo": "bar",
+								},
+							},
 							Spec: actionsv1alpha1.RunnerSpec{
 								Repository: "test/valid",
 								Image:      "bar",
@@ -338,7 +468,11 @@ var _ = Context("INTEGRATION: Inside of a new namespace", func() {
 						MinReplicas:                       intPtr(1),
 						MaxReplicas:                       intPtr(5),
 						ScaleDownDelaySecondsAfterScaleUp: intPtr(1),
-						Metrics:                           nil,
+						Metrics: []actionsv1alpha1.MetricSpec{
+							{
+								Type: actionsv1alpha1.AutoscalingMetricTypeTotalNumberOfQueuedAndInProgressWorkflowRuns,
+							},
+						},
 						ScaleUpTriggers: []actionsv1alpha1.ScaleUpTrigger{
 							{
 								GitHubEvent: &actionsv1alpha1.GitHubEventScaleUpTriggerSpec{
@@ -358,10 +492,9 @@ var _ = Context("INTEGRATION: Inside of a new namespace", func() {
 
 				ExpectRunnerSetsCountEventuallyEquals(ctx, ns.Name, 1)
 				ExpectRunnerSetsManagedReplicasCountEventuallyEquals(ctx, ns.Name, 3)
-			}
-
-			{
 				env.ExpectRegisteredNumberCountEventuallyEquals(3, "count of fake list runners")
+				env.SyncRunnerRegistrations()
+				ExpectRunnerCountEventuallyEquals(ctx, ns.Name, 3)
 			}
 
 			// Scale-up to 4 replicas on first check_run create webhook event
@@ -369,19 +502,123 @@ var _ = Context("INTEGRATION: Inside of a new namespace", func() {
 				env.SendOrgCheckRunEvent("test", "valid", "pending", "created")
 				ExpectRunnerSetsCountEventuallyEquals(ctx, ns.Name, 1, "runner sets after webhook")
 				ExpectRunnerSetsManagedReplicasCountEventuallyEquals(ctx, ns.Name, 4, "runners after first webhook event")
-			}
-
-			{
 				env.ExpectRegisteredNumberCountEventuallyEquals(4, "count of fake list runners")
+				env.SyncRunnerRegistrations()
+				ExpectRunnerCountEventuallyEquals(ctx, ns.Name, 4)
 			}
 
 			// Scale-up to 5 replicas on second check_run create webhook event
 			{
 				env.SendOrgCheckRunEvent("test", "valid", "pending", "created")
 				ExpectRunnerSetsManagedReplicasCountEventuallyEquals(ctx, ns.Name, 5, "runners after second webhook event")
+				env.ExpectRegisteredNumberCountEventuallyEquals(5, "count of fake list runners")
+				env.SyncRunnerRegistrations()
+				ExpectRunnerCountEventuallyEquals(ctx, ns.Name, 5)
+			}
+		})
+
+		It("should create and scale organization's repository runners only on check_run event", func() {
+			name := "example-runnerdeploy"
+
+			{
+				rd := &actionsv1alpha1.RunnerDeployment{
+					ObjectMeta: metav1.ObjectMeta{
+						Name:      name,
+						Namespace: ns.Name,
+					},
+					Spec: actionsv1alpha1.RunnerDeploymentSpec{
+						Replicas: intPtr(1),
+						Selector: &metav1.LabelSelector{
+							MatchLabels: map[string]string{
+								"foo": "bar",
+							},
+						},
+						Template: actionsv1alpha1.RunnerTemplate{
+							ObjectMeta: metav1.ObjectMeta{
+								Labels: map[string]string{
+									"foo": "bar",
+								},
+							},
+							Spec: actionsv1alpha1.RunnerSpec{
+								Repository: "test/valid",
+								Image:      "bar",
+								Group:      "baz",
+								Env: []corev1.EnvVar{
+									{Name: "FOO", Value: "FOOVALUE"},
+								},
+							},
+						},
+					},
 				}
 
-			env.ExpectRegisteredNumberCountEventuallyEquals(5, "count of fake list runners")
+				ExpectCreate(ctx, rd, "test RunnerDeployment")
+				ExpectRunnerSetsCountEventuallyEquals(ctx, ns.Name, 1)
+				ExpectRunnerSetsManagedReplicasCountEventuallyEquals(ctx, ns.Name, 1)
+			}
+
+			{
+				env.ExpectRegisteredNumberCountEventuallyEquals(1, "count of fake list runners")
+			}
+
+			// Scale-up to 3 replicas by the default TotalNumberOfQueuedAndInProgressWorkflowRuns-based scaling
+			// See workflowRunsFor3Replicas_queued and workflowRunsFor3Replicas_in_progress for GitHub List-Runners API responses
+			// used while testing.
+			{
+				hra := &actionsv1alpha1.HorizontalRunnerAutoscaler{
+					ObjectMeta: metav1.ObjectMeta{
+						Name:      name,
+						Namespace: ns.Name,
+					},
+					Spec: actionsv1alpha1.HorizontalRunnerAutoscalerSpec{
+						ScaleTargetRef: actionsv1alpha1.ScaleTargetRef{
+							Name: name,
+						},
+						MinReplicas:                       intPtr(1),
+						MaxReplicas:                       intPtr(5),
+						ScaleDownDelaySecondsAfterScaleUp: intPtr(1),
+						ScaleUpTriggers: []actionsv1alpha1.ScaleUpTrigger{
+							{
+								GitHubEvent: &actionsv1alpha1.GitHubEventScaleUpTriggerSpec{
+									CheckRun: &actionsv1alpha1.CheckRunSpec{
+										Types:  []string{"created"},
+										Status: "pending",
+									},
+								},
+								Amount:   1,
+								Duration: metav1.Duration{Duration: time.Minute},
+							},
+						},
+					},
+				}
+
+				ExpectCreate(ctx, hra, "test HorizontalRunnerAutoscaler")
+
+				ExpectRunnerSetsCountEventuallyEquals(ctx, ns.Name, 1)
+				ExpectRunnerSetsManagedReplicasCountEventuallyEquals(ctx, ns.Name, 1)
+			}
+
+			{
+				env.ExpectRegisteredNumberCountEventuallyEquals(1, "count of fake list runners")
+			}
+
+			// Scale-up to 2 replicas on first check_run create webhook event
+			{
+				env.SendOrgCheckRunEvent("test", "valid", "pending", "created")
+				ExpectRunnerSetsCountEventuallyEquals(ctx, ns.Name, 1, "runner sets after webhook")
+				ExpectRunnerSetsManagedReplicasCountEventuallyEquals(ctx, ns.Name, 2, "runners after first webhook event")
+			}
+
+			{
+				env.ExpectRegisteredNumberCountEventuallyEquals(2, "count of fake list runners")
+			}
+
+			// Scale-up to 3 replicas on second check_run create webhook event
+			{
+				env.SendOrgCheckRunEvent("test", "valid", "pending", "created")
+				ExpectRunnerSetsManagedReplicasCountEventuallyEquals(ctx, ns.Name, 3, "runners after second webhook event")
+			}
+
+			env.ExpectRegisteredNumberCountEventuallyEquals(3, "count of fake list runners")
 		})
 
 		It("should create and scale user's repository runners on pull_request event", func() {
@@ -395,7 +632,17 @@ var _ = Context("INTEGRATION: Inside of a new namespace", func() {
 					},
 					Spec: actionsv1alpha1.RunnerDeploymentSpec{
 						Replicas: intPtr(1),
+						Selector: &metav1.LabelSelector{
+							MatchLabels: map[string]string{
+								"foo": "bar",
+							},
+						},
 						Template: actionsv1alpha1.RunnerTemplate{
+							ObjectMeta: metav1.ObjectMeta{
+								Labels: map[string]string{
+									"foo": "bar",
+								},
+							},
 							Spec: actionsv1alpha1.RunnerSpec{
 								Repository: "test/valid",
 								Image:      "bar",
@@ -435,7 +682,11 @@ var _ = Context("INTEGRATION: Inside of a new namespace", func() {
 						MinReplicas:                       intPtr(1),
 						MaxReplicas:                       intPtr(3),
 						ScaleDownDelaySecondsAfterScaleUp: intPtr(1),
-						Metrics:                           nil,
+						Metrics: []actionsv1alpha1.MetricSpec{
+							{
+								Type: actionsv1alpha1.AutoscalingMetricTypeTotalNumberOfQueuedAndInProgressWorkflowRuns,
+							},
+						},
 						ScaleUpTriggers: []actionsv1alpha1.ScaleUpTrigger{
 							{
 								GitHubEvent: &actionsv1alpha1.GitHubEventScaleUpTriggerSpec{
@@ -503,6 +754,99 @@ var _ = Context("INTEGRATION: Inside of a new namespace", func() {
 			}
 		})
 
+		It("should create and scale user's repository runners only on pull_request event", func() {
+			name := "example-runnerdeploy"
+
+			{
+				rd := &actionsv1alpha1.RunnerDeployment{
+					ObjectMeta: metav1.ObjectMeta{
+						Name:      name,
+						Namespace: ns.Name,
+					},
+					Spec: actionsv1alpha1.RunnerDeploymentSpec{
+						Replicas: intPtr(1),
+						Selector: &metav1.LabelSelector{
+							MatchLabels: map[string]string{
+								"foo": "bar",
+							},
+						},
+						Template: actionsv1alpha1.RunnerTemplate{
+							ObjectMeta: metav1.ObjectMeta{
+								Labels: map[string]string{
+									"foo": "bar",
+								},
+							},
+							Spec: actionsv1alpha1.RunnerSpec{
+								Repository: "test/valid",
+								Image:      "bar",
+								Group:      "baz",
+								Env: []corev1.EnvVar{
+									{Name: "FOO", Value: "FOOVALUE"},
+								},
+							},
+						},
+					},
+				}
+
+				ExpectCreate(ctx, rd, "test RunnerDeployment")
+				ExpectRunnerSetsCountEventuallyEquals(ctx, ns.Name, 1)
+				ExpectRunnerSetsManagedReplicasCountEventuallyEquals(ctx, ns.Name, 1)
+			}
+
+			{
+				hra := &actionsv1alpha1.HorizontalRunnerAutoscaler{
+					ObjectMeta: metav1.ObjectMeta{
+						Name:      name,
+						Namespace: ns.Name,
+					},
+					Spec: actionsv1alpha1.HorizontalRunnerAutoscalerSpec{
+						ScaleTargetRef: actionsv1alpha1.ScaleTargetRef{
+							Name: name,
+						},
+						MinReplicas:                       intPtr(1),
+						MaxReplicas:                       intPtr(3),
+						ScaleDownDelaySecondsAfterScaleUp: intPtr(1),
+						ScaleUpTriggers: []actionsv1alpha1.ScaleUpTrigger{
+							{
+								GitHubEvent: &actionsv1alpha1.GitHubEventScaleUpTriggerSpec{
+									PullRequest: &actionsv1alpha1.PullRequestSpec{
+										Types:    []string{"created"},
+										Branches: []string{"main"},
+									},
+								},
+								Amount:   1,
+								Duration: metav1.Duration{Duration: time.Minute},
+							},
+						},
+					},
+				}
+
+				ExpectCreate(ctx, hra, "test HorizontalRunnerAutoscaler")
+
+				ExpectRunnerSetsCountEventuallyEquals(ctx, ns.Name, 1)
+				ExpectRunnerSetsManagedReplicasCountEventuallyEquals(ctx, ns.Name, 1)
+			}
+
+			{
+				env.ExpectRegisteredNumberCountEventuallyEquals(1, "count of fake runners after HRA creation")
+			}
+
+			// Scale-up to 2 replicas on first pull_request create webhook event
+			{
+				env.SendUserPullRequestEvent("test", "valid", "main", "created")
+				ExpectRunnerSetsCountEventuallyEquals(ctx, ns.Name, 1, "runner sets after webhook")
+				ExpectRunnerSetsManagedReplicasCountEventuallyEquals(ctx, ns.Name, 2, "runners after first webhook event")
+				ExpectHRADesiredReplicasEquals(ctx, ns.Name, name, 2, "runner deployment desired replicas")
+			}
+
+			// Scale-up to 3 replicas on second pull_request create webhook event
+			{
+				env.SendUserPullRequestEvent("test", "valid", "main", "created")
+				ExpectRunnerSetsManagedReplicasCountEventuallyEquals(ctx, ns.Name, 3, "runners after second webhook event")
+				ExpectHRADesiredReplicasEquals(ctx, ns.Name, name, 3, "runner deployment desired replicas")
+			}
+		})
+
 		It("should create and scale user's repository runners on check_run event", func() {
 			name := "example-runnerdeploy"
 
@@ -514,7 +858,17 @@ var _ = Context("INTEGRATION: Inside of a new namespace", func() {
 					},
 					Spec: actionsv1alpha1.RunnerDeploymentSpec{
 						Replicas: intPtr(1),
+						Selector: &metav1.LabelSelector{
+							MatchLabels: map[string]string{
+								"foo": "bar",
+							},
+						},
 						Template: actionsv1alpha1.RunnerTemplate{
+							ObjectMeta: metav1.ObjectMeta{
+								Labels: map[string]string{
+									"foo": "bar",
+								},
+							},
 							Spec: actionsv1alpha1.RunnerSpec{
 								Repository: "test/valid",
 								Image:      "bar",
@@ -552,7 +906,11 @@ var _ = Context("INTEGRATION: Inside of a new namespace", func() {
 						MinReplicas:                       intPtr(1),
 						MaxReplicas:                       intPtr(5),
 						ScaleDownDelaySecondsAfterScaleUp: intPtr(1),
-						Metrics:                           nil,
+						Metrics: []actionsv1alpha1.MetricSpec{
+							{
+								Type: actionsv1alpha1.AutoscalingMetricTypeTotalNumberOfQueuedAndInProgressWorkflowRuns,
+							},
+						},
 						ScaleUpTriggers: []actionsv1alpha1.ScaleUpTrigger{
 							{
 								GitHubEvent: &actionsv1alpha1.GitHubEventScaleUpTriggerSpec{
@@ -598,9 +956,128 @@ var _ = Context("INTEGRATION: Inside of a new namespace", func() {
 			env.ExpectRegisteredNumberCountEventuallyEquals(5, "count of fake list runners")
 		})
 
+		It("should create and scale user's repository runners only on check_run event", func() {
+			name := "example-runnerdeploy"
+
+			{
+				rd := &actionsv1alpha1.RunnerDeployment{
+					ObjectMeta: metav1.ObjectMeta{
+						Name:      name,
+						Namespace: ns.Name,
+					},
+					Spec: actionsv1alpha1.RunnerDeploymentSpec{
+						Replicas: intPtr(1),
+						Selector: &metav1.LabelSelector{
+							MatchLabels: map[string]string{
+								"foo": "bar",
+							},
+						},
+						Template: actionsv1alpha1.RunnerTemplate{
+							ObjectMeta: metav1.ObjectMeta{
+								Labels: map[string]string{
+									"foo": "bar",
+								},
+							},
+							Spec: actionsv1alpha1.RunnerSpec{
+								Repository: "test/valid",
+								Image:      "bar",
+								Group:      "baz",
+								Env: []corev1.EnvVar{
+									{Name: "FOO", Value: "FOOVALUE"},
+								},
+							},
+						},
+					},
+				}
+
+				ExpectCreate(ctx, rd, "test RunnerDeployment")
+				ExpectRunnerSetsCountEventuallyEquals(ctx, ns.Name, 1)
+				ExpectRunnerSetsManagedReplicasCountEventuallyEquals(ctx, ns.Name, 1)
+			}
+
+			{
+				env.ExpectRegisteredNumberCountEventuallyEquals(1, "count of fake list runners")
+			}
+
+			// Scale-up to 3 replicas by the default TotalNumberOfQueuedAndInProgressWorkflowRuns-based scaling
+			// See workflowRunsFor3Replicas_queued and workflowRunsFor3Replicas_in_progress for GitHub List-Runners API responses
+			// used while testing.
+			{
+				hra := &actionsv1alpha1.HorizontalRunnerAutoscaler{
+					ObjectMeta: metav1.ObjectMeta{
+						Name:      name,
+						Namespace: ns.Name,
+					},
+					Spec: actionsv1alpha1.HorizontalRunnerAutoscalerSpec{
+						ScaleTargetRef: actionsv1alpha1.ScaleTargetRef{
+							Name: name,
+						},
+						MinReplicas:                       intPtr(1),
+						MaxReplicas:                       intPtr(5),
+						ScaleDownDelaySecondsAfterScaleUp: intPtr(1),
+						ScaleUpTriggers: []actionsv1alpha1.ScaleUpTrigger{
+							{
+								GitHubEvent: &actionsv1alpha1.GitHubEventScaleUpTriggerSpec{
+									CheckRun: &actionsv1alpha1.CheckRunSpec{
+										Types:  []string{"created"},
+										Status: "pending",
+									},
+								},
+								Amount:   1,
+								Duration: metav1.Duration{Duration: time.Minute},
+							},
+						},
+					},
+				}
+
+				ExpectCreate(ctx, hra, "test HorizontalRunnerAutoscaler")
+
+				ExpectRunnerSetsCountEventuallyEquals(ctx, ns.Name, 1)
+				ExpectRunnerSetsManagedReplicasCountEventuallyEquals(ctx, ns.Name, 1)
+			}
+
+			{
+				env.ExpectRegisteredNumberCountEventuallyEquals(1, "count of fake list runners")
+			}
+
+			// Scale-up to 2 replicas on first check_run create webhook event
+			{
+				env.SendUserCheckRunEvent("test", "valid", "pending", "created")
+				ExpectRunnerSetsCountEventuallyEquals(ctx, ns.Name, 1, "runner sets after webhook")
+				ExpectRunnerSetsManagedReplicasCountEventuallyEquals(ctx, ns.Name, 2, "runners after first webhook event")
+			}
+
+			{
+				env.ExpectRegisteredNumberCountEventuallyEquals(2, "count of fake list runners")
+			}
+
+			// Scale-up to 3 replicas on second check_run create webhook event
+			{
+				env.SendUserCheckRunEvent("test", "valid", "pending", "created")
+				ExpectRunnerSetsManagedReplicasCountEventuallyEquals(ctx, ns.Name, 3, "runners after second webhook event")
+			}
+
+			env.ExpectRegisteredNumberCountEventuallyEquals(3, "count of fake list runners")
+		})
+
 	})
 })
 
+func ExpectHRAStatusCacheEntryLengthEventuallyEquals(ctx context.Context, ns string, name string, value int, optionalDescriptions ...interface{}) {
+	EventuallyWithOffset(
+		1,
+		func() int {
+			var hra actionsv1alpha1.HorizontalRunnerAutoscaler
+
+			err := k8sClient.Get(ctx, types.NamespacedName{Namespace: ns, Name: name}, &hra)
+
+			ExpectWithOffset(1, err).NotTo(HaveOccurred(), "failed to get test HRA resource")
+
+			return len(hra.Status.CacheEntries)
+		},
+		time.Second*5, time.Millisecond*500).Should(Equal(value), optionalDescriptions...)
+}
+
 func ExpectHRADesiredReplicasEquals(ctx context.Context, ns, name string, desired int, optionalDescriptions ...interface{}) {
 	var rd actionsv1alpha1.HorizontalRunnerAutoscaler
 
@@ -767,6 +1244,44 @@ func ExpectRunnerSetsCountEventuallyEquals(ctx context.Context, ns string, count
 		time.Second*10, time.Millisecond*500).Should(BeEquivalentTo(count), optionalDescription...)
 }
 
+func ExpectRunnerCountEventuallyEquals(ctx context.Context, ns string, count int, optionalDescription ...interface{}) {
+	runners := actionsv1alpha1.RunnerList{Items: []actionsv1alpha1.Runner{}}
+
+	EventuallyWithOffset(
+		1,
+		func() int {
+			err := k8sClient.List(ctx, &runners, client.InNamespace(ns))
+			if err != nil {
+				logf.Log.Error(err, "list runner sets")
+			}
+
+			var running int
+
+			for _, r := range runners.Items {
+				if r.Status.Phase == string(corev1.PodRunning) {
+					running++
+				} else {
+					var pod corev1.Pod
+					if err := k8sClient.Get(ctx, types.NamespacedName{Namespace: ns, Name: r.Name}, &pod); err != nil {
+						logf.Log.Error(err, "simulating pod controller")
+						continue
+					}
+
+					copy := pod.DeepCopy()
+					copy.Status.Phase = corev1.PodRunning
+
+					if err := k8sClient.Status().Patch(ctx, copy, client.MergeFrom(&pod)); err != nil {
+						logf.Log.Error(err, "simulating pod controller")
+						continue
+					}
+				}
+			}
+
+			return running
+		},
+		time.Second*10, time.Millisecond*500).Should(BeEquivalentTo(count), optionalDescription...)
+}
+
 func ExpectRunnerSetsManagedReplicasCountEventuallyEquals(ctx context.Context, ns string, count int, optionalDescription ...interface{}) {
 	runnerSets := actionsv1alpha1.RunnerReplicaSetList{Items: []actionsv1alpha1.RunnerReplicaSet{}}
 

controllers/metrics/horizontalrunnerautoscaler.go

@@ -0,0 +1,67 @@
+package metrics
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/summerwind/actions-runner-controller/api/v1alpha1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+const (
+	hraName      = "horizontalrunnerautoscaler"
+	hraNamespace = "namespace"
+)
+
+var (
+	horizontalRunnerAutoscalerMetrics = []prometheus.Collector{
+		horizontalRunnerAutoscalerMinReplicas,
+		horizontalRunnerAutoscalerMaxReplicas,
+		horizontalRunnerAutoscalerDesiredReplicas,
+	}
+)
+
+var (
+	horizontalRunnerAutoscalerMinReplicas = prometheus.NewGaugeVec(
+		prometheus.GaugeOpts{
+			Name: "horizontalrunnerautoscaler_spec_min_replicas",
+			Help: "minReplicas of HorizontalRunnerAutoscaler",
+		},
+		[]string{hraName, hraNamespace},
+	)
+	horizontalRunnerAutoscalerMaxReplicas = prometheus.NewGaugeVec(
+		prometheus.GaugeOpts{
+			Name: "horizontalrunnerautoscaler_spec_max_replicas",
+			Help: "maxReplicas of HorizontalRunnerAutoscaler",
+		},
+		[]string{hraName, hraNamespace},
+	)
+	horizontalRunnerAutoscalerDesiredReplicas = prometheus.NewGaugeVec(
+		prometheus.GaugeOpts{
+			Name: "horizontalrunnerautoscaler_status_desired_replicas",
+			Help: "desiredReplicas of HorizontalRunnerAutoscaler",
+		},
+		[]string{hraName, hraNamespace},
+	)
+)
+
+func SetHorizontalRunnerAutoscalerSpec(o metav1.ObjectMeta, spec v1alpha1.HorizontalRunnerAutoscalerSpec) {
+	labels := prometheus.Labels{
+		hraName:      o.Name,
+		hraNamespace: o.Namespace,
+	}
+	if spec.MaxReplicas != nil {
+		horizontalRunnerAutoscalerMaxReplicas.With(labels).Set(float64(*spec.MaxReplicas))
+	}
+	if spec.MinReplicas != nil {
+		horizontalRunnerAutoscalerMinReplicas.With(labels).Set(float64(*spec.MinReplicas))
+	}
+}
+
+func SetHorizontalRunnerAutoscalerStatus(o metav1.ObjectMeta, status v1alpha1.HorizontalRunnerAutoscalerStatus) {
+	labels := prometheus.Labels{
+		hraName:      o.Name,
+		hraNamespace: o.Namespace,
+	}
+	if status.DesiredReplicas != nil {
+		horizontalRunnerAutoscalerDesiredReplicas.With(labels).Set(float64(*status.DesiredReplicas))
+	}
+}

controllers/metrics/metrics.go

@@ -0,0 +1,14 @@
+// Package metrics provides the metrics of custom resources such as HRA.
+//
+// This depends on the metrics exporter of kubebuilder.
+// See https://book.kubebuilder.io/reference/metrics.html for details.
+package metrics
+
+import (
+	"sigs.k8s.io/controller-runtime/pkg/metrics"
+)
+
+func init() {
+	metrics.Registry.MustRegister(runnerDeploymentMetrics...)
+	metrics.Registry.MustRegister(horizontalRunnerAutoscalerMetrics...)
+}

controllers/metrics/runnerdeployment.go

@@ -0,0 +1,37 @@
+package metrics
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/summerwind/actions-runner-controller/api/v1alpha1"
+)
+
+const (
+	rdName      = "runnerdeployment"
+	rdNamespace = "namespace"
+)
+
+var (
+	runnerDeploymentMetrics = []prometheus.Collector{
+		runnerDeploymentReplicas,
+	}
+)
+
+var (
+	runnerDeploymentReplicas = prometheus.NewGaugeVec(
+		prometheus.GaugeOpts{
+			Name: "runnerdeployment_spec_replicas",
+			Help: "replicas of RunnerDeployment",
+		},
+		[]string{rdName, rdNamespace},
+	)
+)
+
+func SetRunnerDeployment(rd v1alpha1.RunnerDeployment) {
+	labels := prometheus.Labels{
+		rdName:      rd.Name,
+		rdNamespace: rd.Namespace,
+	}
+	if rd.Spec.Replicas != nil {
+		runnerDeploymentReplicas.With(labels).Set(float64(*rd.Spec.Replicas))
+	}
+}

controllers/runner_controller.go

@@ -22,6 +22,7 @@ import (
 	"fmt"
 	gogithub "github.com/google/go-github/v33/github"
 	"github.com/summerwind/actions-runner-controller/hash"
+	"k8s.io/apimachinery/pkg/util/wait"
 	"strings"
 	"time"
 
@@ -57,6 +58,9 @@ type RunnerReconciler struct {
 	GitHubClient                *github.Client
 	RunnerImage                 string
 	DockerImage                 string
+	Name                        string
+	RegistrationRecheckInterval time.Duration
+	RegistrationRecheckJitter   time.Duration
 }
 
 // +kubebuilder:rbac:groups=actions.summerwind.dev,resources=runners,verbs=get;list;watch;create;update;patch;delete
@@ -129,8 +133,8 @@ func (r *RunnerReconciler) Reconcile(req ctrl.Request) (ctrl.Result, error) {
 			newRunner := runner.DeepCopy()
 			newRunner.ObjectMeta.Finalizers = finalizers
 
-			if err := r.Update(ctx, newRunner); err != nil {
-				log.Error(err, "Failed to update runner")
+			if err := r.Patch(ctx, newRunner, client.MergeFrom(&runner)); err != nil {
+				log.Error(err, "Failed to update runner for finalizer removal")
 				return ctrl.Result{}, err
 			}
 
@@ -159,31 +163,25 @@ func (r *RunnerReconciler) Reconcile(req ctrl.Request) (ctrl.Result, error) {
 		}
 
 		if err := r.Create(ctx, &newPod); err != nil {
+			if kerrors.IsAlreadyExists(err) {
+				// Gracefully handle pod-already-exists errors due to informer cache delay.
+				// Without this we got a few errors like the below on new runner pod:
+				// 2021-03-16T00:23:10.116Z        ERROR   controller-runtime.controller   Reconciler error      {"controller": "runner-controller", "request": "default/example-runnerdeploy-b2g2g-j4mcp", "error": "pods \"example-runnerdeploy-b2g2g-j4mcp\" already exists"}
+				log.Info(
+					"Failed to create pod due to AlreadyExists error. Probably this pod has been already created in previous reconcilation but is still not in the informer cache. Will retry on pod created. If it doesn't repeat, there's no problem",
+				)
+
+				return ctrl.Result{}, nil
+			}
+
 			log.Error(err, "Failed to create pod resource")
+
 			return ctrl.Result{}, err
 		}
 
 		r.Recorder.Event(&runner, corev1.EventTypeNormal, "PodCreated", fmt.Sprintf("Created pod '%s'", newPod.Name))
 		log.Info("Created runner pod", "repository", runner.Spec.Repository)
 	} else {
-		// If pod has ended up succeeded we need to restart it
-		// Happens e.g. when dind is in runner and run completes
-		restart := pod.Status.Phase == corev1.PodSucceeded
-
-		if !restart && runner.Status.Phase != string(pod.Status.Phase) {
-			updated := runner.DeepCopy()
-			updated.Status.Phase = string(pod.Status.Phase)
-			updated.Status.Reason = pod.Status.Reason
-			updated.Status.Message = pod.Status.Message
-
-			if err := r.Status().Update(ctx, updated); err != nil {
-				log.Error(err, "Failed to update runner status")
-				return ctrl.Result{}, err
-			}
-
-			return ctrl.Result{}, nil
-		}
-
 		if !pod.ObjectMeta.DeletionTimestamp.IsZero() {
 			deletionTimeout := 1 * time.Minute
 			currentTime := time.Now()
@@ -191,7 +189,7 @@ func (r *RunnerReconciler) Reconcile(req ctrl.Request) (ctrl.Result, error) {
 
 			if deletionDidTimeout {
 				log.Info(
-					"Pod failed to delete itself in a timely manner. "+
+					fmt.Sprintf("Failed to delete pod within %s. ", deletionTimeout)+
 						"This is typically the case when a Kubernetes node became unreachable "+
 						"and the kube controller started evicting nodes. Forcefully deleting the pod to not get stuck.",
 					"podDeletionTimestamp", pod.DeletionTimestamp,
@@ -220,6 +218,10 @@ func (r *RunnerReconciler) Reconcile(req ctrl.Request) (ctrl.Result, error) {
 			}
 		}
 
+		// If pod has ended up succeeded we need to restart it
+		// Happens e.g. when dind is in runner and run completes
+		restart := pod.Status.Phase == corev1.PodSucceeded
+
 		if pod.Status.Phase == corev1.PodRunning {
 			for _, status := range pod.Status.ContainerStatuses {
 				if status.Name != containerName {
@@ -244,24 +246,61 @@ func (r *RunnerReconciler) Reconcile(req ctrl.Request) (ctrl.Result, error) {
 			return ctrl.Result{}, err
 		}
 
+		var registrationRecheckDelay time.Duration
+
 		// all checks done below only decide whether a restart is needed
 		// if a restart was already decided before, there is no need for the checks
-		// saving API calls and scary log messages
+		// saving API calls and scary{ log messages
 		if !restart {
+			registrationCheckInterval := time.Minute
+			if r.RegistrationRecheckInterval > 0 {
+				registrationCheckInterval = r.RegistrationRecheckInterval
+			}
 
-			notRegistered := false
+			// We want to call ListRunners GitHub Actions API only once per runner per minute.
+			// This if block, in conjunction with:
+			//   return ctrl.Result{RequeueAfter: registrationRecheckDelay}, nil
+			// achieves that.
+			if lastCheckTime := runner.Status.LastRegistrationCheckTime; lastCheckTime != nil {
+				nextCheckTime := lastCheckTime.Add(registrationCheckInterval)
+				now := time.Now()
+
+				// Requeue scheduled by RequeueAfter can happen a bit earlier (like dozens of milliseconds)
+				// so to avoid excessive, in-effective retry, we heuristically ignore the remaining delay in case it is
+				// shorter than 1s
+				requeueAfter := nextCheckTime.Sub(now) - time.Second
+				if requeueAfter > 0 {
+					log.Info(
+						fmt.Sprintf("Skipped registration check because it's deferred until %s. Retrying in %s at latest", nextCheckTime, requeueAfter),
+						"lastRegistrationCheckTime", lastCheckTime,
+						"registrationCheckInterval", registrationCheckInterval,
+					)
+
+					// Without RequeueAfter, the controller may not retry on scheduled. Instead, it must wait until the
+					// next sync period passes, which can be too much later than nextCheckTime.
+					//
+					// We need to requeue on this reconcilation even though we have already scheduled the initial
+					// requeue previously with `return ctrl.Result{RequeueAfter: registrationRecheckDelay}, nil`.
+					// Apparently, the workqueue used by controller-runtime seems to deduplicate and resets the delay on
+					// other requeues- so the initial scheduled requeue may have been reset due to requeue on
+					// spec/status change.
+					return ctrl.Result{RequeueAfter: requeueAfter}, nil
+				}
+			}
+
+			notFound := false
 			offline := false
 
 			runnerBusy, err := r.GitHubClient.IsRunnerBusy(ctx, runner.Spec.Enterprise, runner.Spec.Organization, runner.Spec.Repository, runner.Name)
+
+			currentTime := time.Now()
+
 			if err != nil {
 				var notFoundException *github.RunnerNotFound
 				var offlineException *github.RunnerOffline
 				if errors.As(err, &notFoundException) {
-					log.V(1).Info("Failed to check if runner is busy. Either this runner has never been successfully registered to GitHub or it still needs more time.", "runnerName", runner.Name)
-
-					notRegistered = true
+					notFound = true
 				} else if errors.As(err, &offlineException) {
-					log.V(1).Info("GitHub runner appears to be offline, waiting for runner to get online ...", "runnerName", runner.Name)
 					offline = true
 				} else {
 					var e *gogithub.RateLimitError
@@ -293,10 +332,11 @@ func (r *RunnerReconciler) Reconcile(req ctrl.Request) (ctrl.Result, error) {
 			}
 
 			registrationTimeout := 10 * time.Minute
-			currentTime := time.Now()
-			registrationDidTimeout := currentTime.Sub(pod.CreationTimestamp.Add(registrationTimeout)) > 0
+			durationAfterRegistrationTimeout := currentTime.Sub(pod.CreationTimestamp.Add(registrationTimeout))
+			registrationDidTimeout := durationAfterRegistrationTimeout > 0
 
-			if notRegistered && registrationDidTimeout {
+			if notFound {
+				if registrationDidTimeout {
 					log.Info(
 						"Runner failed to register itself to GitHub in timely manner. "+
 							"Recreating the pod to see if it resolves the issue. "+
@@ -308,9 +348,14 @@ func (r *RunnerReconciler) Reconcile(req ctrl.Request) (ctrl.Result, error) {
 					)
 
 					restart = true
+				} else {
+					log.V(1).Info(
+						"Runner pod exists but we failed to check if runner is busy. Apparently it still needs more time.",
+						"runnerName", runner.Name,
+					)
 				}
-
-			if offline && registrationDidTimeout {
+			} else if offline {
+				if registrationDidTimeout {
 					log.Info(
 						"Already existing GitHub runner still appears offline . "+
 							"Recreating the pod to see if it resolves the issue. "+
@@ -321,12 +366,62 @@ func (r *RunnerReconciler) Reconcile(req ctrl.Request) (ctrl.Result, error) {
 					)
 
 					restart = true
+				} else {
+					log.V(1).Info(
+						"Runner pod exists but the GitHub runner appears to be still offline. Waiting for runner to get online ...",
+						"runnerName", runner.Name,
+					)
+				}
 			}
 
+			if (notFound || offline) && !registrationDidTimeout {
+				registrationRecheckJitter := 10 * time.Second
+				if r.RegistrationRecheckJitter > 0 {
+					registrationRecheckJitter = r.RegistrationRecheckJitter
+				}
+
+				registrationRecheckDelay = registrationCheckInterval + wait.Jitter(registrationRecheckJitter, 0.1)
+			}
 		}
 
 		// Don't do anything if there's no need to restart the runner
 		if !restart {
+			// This guard enables us to update runner.Status.Phase to `Running` only after
+			// the runner is registered to GitHub.
+			if registrationRecheckDelay > 0 {
+				log.V(1).Info(fmt.Sprintf("Rechecking the runner registration in %s", registrationRecheckDelay))
+
+				updated := runner.DeepCopy()
+				updated.Status.LastRegistrationCheckTime = &metav1.Time{Time: time.Now()}
+
+				if err := r.Status().Patch(ctx, updated, client.MergeFrom(&runner)); err != nil {
+					log.Error(err, "Failed to update runner status for LastRegistrationCheckTime")
+					return ctrl.Result{}, err
+				}
+
+				return ctrl.Result{RequeueAfter: registrationRecheckDelay}, nil
+			}
+
+			if runner.Status.Phase != string(pod.Status.Phase) {
+				if pod.Status.Phase == corev1.PodRunning {
+					// Seeing this message, you can expect the runner to become `Running` soon.
+					log.Info(
+						"Runner appears to have registered and running.",
+						"podCreationTimestamp", pod.CreationTimestamp,
+					)
+				}
+
+				updated := runner.DeepCopy()
+				updated.Status.Phase = string(pod.Status.Phase)
+				updated.Status.Reason = pod.Status.Reason
+				updated.Status.Message = pod.Status.Message
+
+				if err := r.Status().Patch(ctx, updated, client.MergeFrom(&runner)); err != nil {
+					log.Error(err, "Failed to update runner status for Phase/Reason/Message")
+					return ctrl.Result{}, err
+				}
+			}
+
 			return ctrl.Result{}, nil
 		}
 
@@ -394,8 +489,8 @@ func (r *RunnerReconciler) updateRegistrationToken(ctx context.Context, runner v
 		ExpiresAt:    metav1.NewTime(rt.GetExpiresAt().Time),
 	}
 
-	if err := r.Status().Update(ctx, updated); err != nil {
-		log.Error(err, "Failed to update runner status")
+	if err := r.Status().Patch(ctx, updated, client.MergeFrom(&runner)); err != nil {
+		log.Error(err, "Failed to update runner status for Registration")
 		return false, err
 	}
 
@@ -530,45 +625,67 @@ func (r *RunnerReconciler) newPod(runner v1alpha1.Runner) (corev1.Pod, error) {
 		},
 	}
 
-	if !dockerdInRunner && dockerEnabled {
+	if mtu := runner.Spec.DockerMTU; mtu != nil && dockerdInRunner {
+		pod.Spec.Containers[0].Env = append(pod.Spec.Containers[0].Env, []corev1.EnvVar{
+			{
+				Name:  "MTU",
+				Value: fmt.Sprintf("%d", *runner.Spec.DockerMTU),
+			},
+		}...)
+	}
+
+	//
+	// /runner must be generated on runtime from /runnertmp embedded in the container image.
+	//
+	// When you're NOT using dindWithinRunner=true,
+	// it must also be shared with the dind container as it seems like required to run docker steps.
+	//
+
 	runnerVolumeName := "runner"
 	runnerVolumeMountPath := "/runner"
 
-		pod.Spec.Volumes = []corev1.Volume{
-			{
-				Name: "work",
-				VolumeSource: corev1.VolumeSource{
-					EmptyDir: &corev1.EmptyDirVolumeSource{},
-				},
-			},
-			{
+	pod.Spec.Volumes = append(pod.Spec.Volumes,
+		corev1.Volume{
 			Name: runnerVolumeName,
 			VolumeSource: corev1.VolumeSource{
 				EmptyDir: &corev1.EmptyDirVolumeSource{},
 			},
 		},
-			{
+	)
+
+	pod.Spec.Containers[0].VolumeMounts = append(pod.Spec.Containers[0].VolumeMounts,
+		corev1.VolumeMount{
+			Name:      runnerVolumeName,
+			MountPath: runnerVolumeMountPath,
+		},
+	)
+
+	if !dockerdInRunner && dockerEnabled {
+		pod.Spec.Volumes = append(pod.Spec.Volumes,
+			corev1.Volume{
+				Name: "work",
+				VolumeSource: corev1.VolumeSource{
+					EmptyDir: &corev1.EmptyDirVolumeSource{},
+				},
+			},
+			corev1.Volume{
 				Name: "certs-client",
 				VolumeSource: corev1.VolumeSource{
 					EmptyDir: &corev1.EmptyDirVolumeSource{},
 				},
 			},
-		}
-		pod.Spec.Containers[0].VolumeMounts = []corev1.VolumeMount{
-			{
+		)
+		pod.Spec.Containers[0].VolumeMounts = append(pod.Spec.Containers[0].VolumeMounts,
+			corev1.VolumeMount{
 				Name:      "work",
 				MountPath: workDir,
 			},
-			{
-				Name:      runnerVolumeName,
-				MountPath: runnerVolumeMountPath,
-			},
-			{
+			corev1.VolumeMount{
 				Name:      "certs-client",
 				MountPath: "/certs/client",
 				ReadOnly:  true,
 			},
-		}
+		)
 		pod.Spec.Containers[0].Env = append(pod.Spec.Containers[0].Env, []corev1.EnvVar{
 			{
 				Name:  "DOCKER_HOST",
@@ -586,6 +703,7 @@ func (r *RunnerReconciler) newPod(runner v1alpha1.Runner) (corev1.Pod, error) {
 		pod.Spec.Containers = append(pod.Spec.Containers, corev1.Container{
 			Name:  "docker",
 			Image: r.DockerImage,
+			Args:  []string{"dockerd"},
 			VolumeMounts: []corev1.VolumeMount{
 				{
 					Name:      "work",
@@ -612,6 +730,21 @@ func (r *RunnerReconciler) newPod(runner v1alpha1.Runner) (corev1.Pod, error) {
 			Resources: runner.Spec.DockerdContainerResources,
 		})
 
+		if mtu := runner.Spec.DockerMTU; mtu != nil {
+			pod.Spec.Containers[1].Env = append(pod.Spec.Containers[1].Env, []corev1.EnvVar{
+				// See https://docs.docker.com/engine/security/rootless/
+				{
+					Name:  "DOCKERD_ROOTLESS_ROOTLESSKIT_MTU",
+					Value: fmt.Sprintf("%d", *runner.Spec.DockerMTU),
+				},
+			}...)
+
+			pod.Spec.Containers[1].Args = append(pod.Spec.Containers[1].Args,
+				"--mtu",
+				fmt.Sprintf("%d", *runner.Spec.DockerMTU),
+			)
+		}
+
 	}
 
 	if len(runner.Spec.Containers) != 0 {
@@ -681,6 +814,9 @@ func (r *RunnerReconciler) newPod(runner v1alpha1.Runner) (corev1.Pod, error) {
 
 func (r *RunnerReconciler) SetupWithManager(mgr ctrl.Manager) error {
 	name := "runner-controller"
+	if r.Name != "" {
+		name = r.Name
+	}
 
 	r.Recorder = mgr.GetEventRecorderFor(name)
 

controllers/runnerdeployment_controller.go

@@ -20,6 +20,7 @@ import (
 	"context"
 	"fmt"
 	"hash/fnv"
+	"reflect"
 	"sort"
 	"time"
 
@@ -37,10 +38,12 @@ import (
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 
 	"github.com/summerwind/actions-runner-controller/api/v1alpha1"
+	"github.com/summerwind/actions-runner-controller/controllers/metrics"
 )
 
 const (
 	LabelKeyRunnerTemplateHash   = "runner-template-hash"
+	LabelKeyRunnerDeploymentName = "runner-deployment-name"
 
 	runnerSetOwnerKey = ".metadata.controller"
 )
@@ -75,6 +78,8 @@ func (r *RunnerDeploymentReconciler) Reconcile(req ctrl.Request) (ctrl.Result, e
 		return ctrl.Result{}, nil
 	}
 
+	metrics.SetRunnerDeployment(rd)
+
 	var myRunnerReplicaSetList v1alpha1.RunnerReplicaSetList
 	if err := r.List(ctx, &myRunnerReplicaSetList, client.InNamespace(req.Namespace), client.MatchingFields{runnerSetOwnerKey: req.Name}); err != nil {
 		return ctrl.Result{}, err
@@ -143,6 +148,28 @@ func (r *RunnerDeploymentReconciler) Reconcile(req ctrl.Request) (ctrl.Result, e
 		return ctrl.Result{RequeueAfter: 5 * time.Second}, nil
 	}
 
+	if !reflect.DeepEqual(newestSet.Spec.Selector, desiredRS.Spec.Selector) {
+		updateSet := newestSet.DeepCopy()
+		updateSet.Spec = *desiredRS.Spec.DeepCopy()
+
+		// A selector update change doesn't trigger replicaset replacement,
+		// but we still need to update the existing replicaset with it.
+		// Otherwise selector-based runner query will never work on replicasets created before the controller v0.17.0
+		// See https://github.com/summerwind/actions-runner-controller/pull/355#discussion_r585379259
+		if err := r.Client.Update(ctx, updateSet); err != nil {
+			log.Error(err, "Failed to update runnerreplicaset resource")
+
+			return ctrl.Result{}, err
+		}
+
+		// At this point, we are already sure that there's no need to create a new replicaset
+		// as the runner template hash is not changed.
+		//
+		// But we still need to requeue for the (possibly rare) cases that there are still old replicasets that needs
+		// to be cleaned up.
+		return ctrl.Result{RequeueAfter: 5 * time.Second}, nil
+	}
+
 	const defaultReplicas = 1
 
 	currentDesiredReplicas := getIntOrDefault(newestSet.Spec.Replicas, defaultReplicas)
@@ -165,14 +192,28 @@ func (r *RunnerDeploymentReconciler) Reconcile(req ctrl.Request) (ctrl.Result, e
 	if len(oldSets) > 0 {
 		readyReplicas := newestSet.Status.ReadyReplicas
 
-		if readyReplicas < currentDesiredReplicas {
-			log.WithValues("runnerreplicaset", types.NamespacedName{
+		oldSetsCount := len(oldSets)
+
+		logWithDebugInfo := log.WithValues(
+			"newest_runnerreplicaset", types.NamespacedName{
 				Namespace: newestSet.Namespace,
 				Name:      newestSet.Name,
-			}).
+			},
+			"newest_runnerreplicaset_replicas_ready", readyReplicas,
+			"newest_runnerreplicaset_replicas_desired", currentDesiredReplicas,
+			"old_runnerreplicasets_count", oldSetsCount,
+		)
+
+		if readyReplicas < currentDesiredReplicas {
+			logWithDebugInfo.
 				Info("Waiting until the newest runnerreplicaset to be 100% available")
 
-			return ctrl.Result{RequeueAfter: 10 * time.Second}, nil
+			return ctrl.Result{}, nil
+		}
+
+		if oldSetsCount > 0 {
+			logWithDebugInfo.
+				Info("The newest runnerreplicaset is 100% available. Deleting old runnerreplicasets")
 		}
 
 		for i := range oldSets {
@@ -258,32 +299,94 @@ func CloneAndAddLabel(labels map[string]string, labelKey, labelValue string) map
 	return newLabels
 }
 
-func (r *RunnerDeploymentReconciler) newRunnerReplicaSet(rd v1alpha1.RunnerDeployment) (*v1alpha1.RunnerReplicaSet, error) {
-	newRSTemplate := *rd.Spec.Template.DeepCopy()
-	templateHash := ComputeHash(&newRSTemplate)
-	// Add template hash label to selector.
-	labels := CloneAndAddLabel(rd.Spec.Template.Labels, LabelKeyRunnerTemplateHash, templateHash)
+// Clones the given selector and returns a new selector with the given key and value added.
+// Returns the given selector, if labelKey is empty.
+//
+// Proudly copied from k8s.io/kubernetes/pkg/util/labels.CloneSelectorAndAddLabel
+func CloneSelectorAndAddLabel(selector *metav1.LabelSelector, labelKey, labelValue string) *metav1.LabelSelector {
+	if labelKey == "" {
+		// Don't need to add a label.
+		return selector
+	}
 
-	for _, l := range r.CommonRunnerLabels {
+	// Clone.
+	newSelector := new(metav1.LabelSelector)
+
+	newSelector.MatchLabels = make(map[string]string)
+	if selector.MatchLabels != nil {
+		for key, val := range selector.MatchLabels {
+			newSelector.MatchLabels[key] = val
+		}
+	}
+	newSelector.MatchLabels[labelKey] = labelValue
+
+	if selector.MatchExpressions != nil {
+		newMExps := make([]metav1.LabelSelectorRequirement, len(selector.MatchExpressions))
+		for i, me := range selector.MatchExpressions {
+			newMExps[i].Key = me.Key
+			newMExps[i].Operator = me.Operator
+			if me.Values != nil {
+				newMExps[i].Values = make([]string, len(me.Values))
+				copy(newMExps[i].Values, me.Values)
+			} else {
+				newMExps[i].Values = nil
+			}
+		}
+		newSelector.MatchExpressions = newMExps
+	} else {
+		newSelector.MatchExpressions = nil
+	}
+
+	return newSelector
+}
+
+func (r *RunnerDeploymentReconciler) newRunnerReplicaSet(rd v1alpha1.RunnerDeployment) (*v1alpha1.RunnerReplicaSet, error) {
+	return newRunnerReplicaSet(&rd, r.CommonRunnerLabels, r.Scheme)
+}
+
+func getSelector(rd *v1alpha1.RunnerDeployment) *metav1.LabelSelector {
+	selector := rd.Spec.Selector
+	if selector == nil {
+		selector = &metav1.LabelSelector{MatchLabels: map[string]string{LabelKeyRunnerDeploymentName: rd.Name}}
+	}
+
+	return selector
+}
+
+func newRunnerReplicaSet(rd *v1alpha1.RunnerDeployment, commonRunnerLabels []string, scheme *runtime.Scheme) (*v1alpha1.RunnerReplicaSet, error) {
+	newRSTemplate := *rd.Spec.Template.DeepCopy()
+
+	for _, l := range commonRunnerLabels {
 		newRSTemplate.Spec.Labels = append(newRSTemplate.Spec.Labels, l)
 	}
 
-	newRSTemplate.Labels = labels
+	templateHash := ComputeHash(&newRSTemplate)
+
+	// Add template hash label to selector.
+	newRSTemplate.ObjectMeta.Labels = CloneAndAddLabel(newRSTemplate.ObjectMeta.Labels, LabelKeyRunnerTemplateHash, templateHash)
+
+	// This label selector is used by default when rd.Spec.Selector is empty.
+	newRSTemplate.ObjectMeta.Labels = CloneAndAddLabel(newRSTemplate.ObjectMeta.Labels, LabelKeyRunnerDeploymentName, rd.Name)
+
+	selector := getSelector(rd)
+
+	newRSSelector := CloneSelectorAndAddLabel(selector, LabelKeyRunnerTemplateHash, templateHash)
 
 	rs := v1alpha1.RunnerReplicaSet{
 		TypeMeta: metav1.TypeMeta{},
 		ObjectMeta: metav1.ObjectMeta{
 			GenerateName: rd.ObjectMeta.Name + "-",
 			Namespace:    rd.ObjectMeta.Namespace,
-			Labels:       labels,
+			Labels:       newRSTemplate.ObjectMeta.Labels,
 		},
 		Spec: v1alpha1.RunnerReplicaSetSpec{
 			Replicas: rd.Spec.Replicas,
+			Selector: newRSSelector,
 			Template: newRSTemplate,
 		},
 	}
 
-	if err := ctrl.SetControllerReference(&rd, &rs, r.Scheme); err != nil {
+	if err := ctrl.SetControllerReference(rd, &rs, scheme); err != nil {
 		return &rs, err
 	}
 

controllers/runnerdeployment_controller_test.go

@@ -2,11 +2,13 @@ package controllers
 
 import (
 	"context"
-	"github.com/google/go-cmp/cmp"
-	"k8s.io/apimachinery/pkg/runtime"
+	"fmt"
 	"testing"
 	"time"
 
+	"github.com/google/go-cmp/cmp"
+	"k8s.io/apimachinery/pkg/runtime"
+
 	corev1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/types"
 	"k8s.io/client-go/kubernetes/scheme"
@@ -36,7 +38,17 @@ func TestNewRunnerReplicaSet(t *testing.T) {
 			Name: "example",
 		},
 		Spec: actionsv1alpha1.RunnerDeploymentSpec{
+			Selector: &metav1.LabelSelector{
+				MatchLabels: map[string]string{
+					"foo": "bar",
+				},
+			},
 			Template: actionsv1alpha1.RunnerTemplate{
+				ObjectMeta: metav1.ObjectMeta{
+					Labels: map[string]string{
+						"foo": "bar",
+					},
+				},
 				Spec: actionsv1alpha1.RunnerSpec{
 					Labels: []string{"project1"},
 				},
@@ -49,10 +61,63 @@ func TestNewRunnerReplicaSet(t *testing.T) {
 		t.Fatalf("%v", err)
 	}
 
-	want := []string{"project1", "dev"}
-	if d := cmp.Diff(want, rs.Spec.Template.Spec.Labels); d != "" {
+	if val, ok := rs.Labels["foo"]; ok {
+		if val != "bar" {
+			t.Errorf("foo label does not have bar but %v", val)
+		}
+	} else {
+		t.Errorf("foo label does not exist")
+	}
+
+	hash1, ok := rs.Labels[LabelKeyRunnerTemplateHash]
+	if !ok {
+		t.Errorf("missing runner-template-hash label")
+	}
+
+	runnerLabel := []string{"project1", "dev"}
+	if d := cmp.Diff(runnerLabel, rs.Spec.Template.Spec.Labels); d != "" {
 		t.Errorf("%s", d)
 	}
+
+	rd2 := rd.DeepCopy()
+	rd2.Spec.Template.Spec.Labels = []string{"project2"}
+
+	rs2, err := r.newRunnerReplicaSet(*rd2)
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+
+	hash2, ok := rs2.Labels[LabelKeyRunnerTemplateHash]
+	if !ok {
+		t.Errorf("missing runner-template-hash label")
+	}
+
+	if hash1 == hash2 {
+		t.Errorf(
+			"runner replica sets from runner deployments with varying labels must have different template hash, but got %s and %s",
+			hash1, hash2,
+		)
+	}
+
+	rd3 := rd.DeepCopy()
+	rd3.Spec.Template.Labels["foo"] = "baz"
+
+	rs3, err := r.newRunnerReplicaSet(*rd3)
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+
+	hash3, ok := rs3.Labels[LabelKeyRunnerTemplateHash]
+	if !ok {
+		t.Errorf("missing runner-template-hash label")
+	}
+
+	if hash1 == hash3 {
+		t.Errorf(
+			"runner replica sets from runner deployments with varying meta labels must have different template hash, but got %s and %s",
+			hash1, hash3,
+		)
+	}
 }
 
 // SetupDeploymentTest will set up a testing environment.
@@ -74,7 +139,9 @@ func SetupDeploymentTest(ctx context.Context) *corev1.Namespace {
 		err := k8sClient.Create(ctx, ns)
 		Expect(err).NotTo(HaveOccurred(), "failed to create test namespace")
 
-		mgr, err := ctrl.NewManager(cfg, ctrl.Options{})
+		mgr, err := ctrl.NewManager(cfg, ctrl.Options{
+			Namespace: ns.Name,
+		})
 		Expect(err).NotTo(HaveOccurred(), "failed to create manager")
 
 		controller := &RunnerDeploymentReconciler{
@@ -112,7 +179,7 @@ var _ = Context("Inside of a new namespace", func() {
 	Describe("when no existing resources exist", func() {
 
 		It("should create a new RunnerReplicaSet resource from the specified template, add a another RunnerReplicaSet on template modification, and eventually removes old runnerreplicasets", func() {
-			name := "example-runnerdeploy"
+			name := "example-runnerdeploy-1"
 
 			{
 				rs := &actionsv1alpha1.RunnerDeployment{
@@ -122,9 +189,19 @@ var _ = Context("Inside of a new namespace", func() {
 					},
 					Spec: actionsv1alpha1.RunnerDeploymentSpec{
 						Replicas: intPtr(1),
+						Selector: &metav1.LabelSelector{
+							MatchLabels: map[string]string{
+								"foo": "bar",
+							},
+						},
 						Template: actionsv1alpha1.RunnerTemplate{
+							ObjectMeta: metav1.ObjectMeta{
+								Labels: map[string]string{
+									"foo": "bar",
+								},
+							},
 							Spec: actionsv1alpha1.RunnerSpec{
-								Repository: "foo/bar",
+								Repository: "test/valid",
 								Image:      "bar",
 								Env: []corev1.EnvVar{
 									{Name: "FOO", Value: "FOOVALUE"},
@@ -141,29 +218,25 @@ var _ = Context("Inside of a new namespace", func() {
 				runnerSets := actionsv1alpha1.RunnerReplicaSetList{Items: []actionsv1alpha1.RunnerReplicaSet{}}
 
 				Eventually(
-					func() int {
-						err := k8sClient.List(ctx, &runnerSets, client.InNamespace(ns.Name))
+					func() (int, error) {
+						selector, err := metav1.LabelSelectorAsSelector(rs.Spec.Selector)
 						if err != nil {
-							logf.Log.Error(err, "list runner sets")
+							return 0, err
 						}
-
-						return len(runnerSets.Items)
-					},
-					time.Second*5, time.Millisecond*500).Should(BeEquivalentTo(1))
-
-				Eventually(
-					func() int {
-						err := k8sClient.List(ctx, &runnerSets, client.InNamespace(ns.Name))
+						err = k8sClient.List(
+							ctx,
+							&runnerSets,
+							client.InNamespace(ns.Name),
+							client.MatchingLabelsSelector{Selector: selector},
+						)
 						if err != nil {
-							logf.Log.Error(err, "list runner sets")
+							return 0, err
+						}
+						if len(runnerSets.Items) != 1 {
+							return 0, fmt.Errorf("runnerreplicasets is not 1 but %d", len(runnerSets.Items))
 						}
 
-						if len(runnerSets.Items) == 0 {
-							logf.Log.Info("No runnerreplicasets exist yet")
-							return -1
-						}
-
-						return *runnerSets.Items[0].Spec.Replicas
+						return *runnerSets.Items[0].Spec.Replicas, nil
 					},
 					time.Second*5, time.Millisecond*500).Should(BeEquivalentTo(1))
 			}
@@ -172,13 +245,12 @@ var _ = Context("Inside of a new namespace", func() {
 				// We wrap the update in the Eventually block to avoid the below error that occurs due to concurrent modification
 				// made by the controller to update .Status.AvailableReplicas and .Status.ReadyReplicas
 				//   Operation cannot be fulfilled on runnersets.actions.summerwind.dev "example-runnerset": the object has been modified; please apply your changes to the latest version and try again
-				Eventually(func() error {
 				var rd actionsv1alpha1.RunnerDeployment
-
+				Eventually(func() error {
 					err := k8sClient.Get(ctx, types.NamespacedName{Namespace: ns.Name, Name: name}, &rd)
-
-					Expect(err).NotTo(HaveOccurred(), "failed to get test RunnerReplicaSet resource")
-
+					if err != nil {
+						return fmt.Errorf("failed to get test RunnerReplicaSet resource: %v\n", err)
+					}
 					rd.Spec.Replicas = intPtr(2)
 
 					return k8sClient.Update(ctx, &rd)
@@ -188,27 +260,222 @@ var _ = Context("Inside of a new namespace", func() {
 				runnerSets := actionsv1alpha1.RunnerReplicaSetList{Items: []actionsv1alpha1.RunnerReplicaSet{}}
 
 				Eventually(
-					func() int {
-						err := k8sClient.List(ctx, &runnerSets, client.InNamespace(ns.Name))
+					func() (int, error) {
+						selector, err := metav1.LabelSelectorAsSelector(rd.Spec.Selector)
 						if err != nil {
-							logf.Log.Error(err, "list runner sets")
+							return 0, err
+						}
+						err = k8sClient.List(
+							ctx,
+							&runnerSets,
+							client.InNamespace(ns.Name),
+							client.MatchingLabelsSelector{Selector: selector},
+						)
+						if err != nil {
+							return 0, err
+						}
+						if len(runnerSets.Items) != 1 {
+							return 0, fmt.Errorf("runnerreplicasets is not 1 but %d", len(runnerSets.Items))
 						}
 
-						return len(runnerSets.Items)
-					},
-					time.Second*5, time.Millisecond*500).Should(BeEquivalentTo(1))
-
-				Eventually(
-					func() int {
-						err := k8sClient.List(ctx, &runnerSets, client.InNamespace(ns.Name))
-						if err != nil {
-							logf.Log.Error(err, "list runner sets")
-						}
-
-						return *runnerSets.Items[0].Spec.Replicas
+						return *runnerSets.Items[0].Spec.Replicas, nil
 					},
 					time.Second*5, time.Millisecond*500).Should(BeEquivalentTo(2))
 			}
 		})
+
+		It("should create a new RunnerReplicaSet resource from the specified template without labels and selector, add a another RunnerReplicaSet on template modification, and eventually removes old runnerreplicasets", func() {
+			name := "example-runnerdeploy-2"
+
+			{
+				rs := &actionsv1alpha1.RunnerDeployment{
+					ObjectMeta: metav1.ObjectMeta{
+						Name:      name,
+						Namespace: ns.Name,
+					},
+					Spec: actionsv1alpha1.RunnerDeploymentSpec{
+						Replicas: intPtr(1),
+						Template: actionsv1alpha1.RunnerTemplate{
+							Spec: actionsv1alpha1.RunnerSpec{
+								Repository: "test/valid",
+								Image:      "bar",
+								Env: []corev1.EnvVar{
+									{Name: "FOO", Value: "FOOVALUE"},
+								},
+							},
+						},
+					},
+				}
+
+				err := k8sClient.Create(ctx, rs)
+
+				Expect(err).NotTo(HaveOccurred(), "failed to create test RunnerReplicaSet resource")
+
+				runnerSets := actionsv1alpha1.RunnerReplicaSetList{Items: []actionsv1alpha1.RunnerReplicaSet{}}
+
+				Eventually(
+					func() (int, error) {
+						selector, err := metav1.LabelSelectorAsSelector(rs.Spec.Selector)
+						if err != nil {
+							return 0, err
+						}
+						err = k8sClient.List(
+							ctx,
+							&runnerSets,
+							client.InNamespace(ns.Name),
+							client.MatchingLabelsSelector{Selector: selector},
+						)
+						if err != nil {
+							return 0, err
+						}
+						if len(runnerSets.Items) != 1 {
+							return 0, fmt.Errorf("runnerreplicasets is not 1 but %d", len(runnerSets.Items))
+						}
+
+						return *runnerSets.Items[0].Spec.Replicas, nil
+					},
+					time.Second*5, time.Millisecond*500).Should(BeEquivalentTo(1))
+			}
+
+			{
+				// We wrap the update in the Eventually block to avoid the below error that occurs due to concurrent modification
+				// made by the controller to update .Status.AvailableReplicas and .Status.ReadyReplicas
+				//   Operation cannot be fulfilled on runnersets.actions.summerwind.dev "example-runnerset": the object has been modified; please apply your changes to the latest version and try again
+				var rd actionsv1alpha1.RunnerDeployment
+				Eventually(func() error {
+					err := k8sClient.Get(ctx, types.NamespacedName{Namespace: ns.Name, Name: name}, &rd)
+					if err != nil {
+						return fmt.Errorf("failed to get test RunnerReplicaSet resource: %v\n", err)
+					}
+					rd.Spec.Replicas = intPtr(2)
+
+					return k8sClient.Update(ctx, &rd)
+				},
+					time.Second*1, time.Millisecond*500).Should(BeNil())
+
+				runnerSets := actionsv1alpha1.RunnerReplicaSetList{Items: []actionsv1alpha1.RunnerReplicaSet{}}
+
+				Eventually(
+					func() (int, error) {
+						selector, err := metav1.LabelSelectorAsSelector(rd.Spec.Selector)
+						if err != nil {
+							return 0, err
+						}
+						err = k8sClient.List(
+							ctx,
+							&runnerSets,
+							client.InNamespace(ns.Name),
+							client.MatchingLabelsSelector{Selector: selector},
+						)
+						if err != nil {
+							return 0, err
+						}
+						if len(runnerSets.Items) != 1 {
+							return 0, fmt.Errorf("runnerreplicasets is not 1 but %d", len(runnerSets.Items))
+						}
+
+						return *runnerSets.Items[0].Spec.Replicas, nil
+					},
+					time.Second*5, time.Millisecond*500).Should(BeEquivalentTo(2))
+			}
+		})
+
+		It("should adopt RunnerReplicaSet created before 0.18.0 to have Spec.Selector", func() {
+			name := "example-runnerdeploy-2"
+
+			{
+				rd := &actionsv1alpha1.RunnerDeployment{
+					ObjectMeta: metav1.ObjectMeta{
+						Name:      name,
+						Namespace: ns.Name,
+					},
+					Spec: actionsv1alpha1.RunnerDeploymentSpec{
+						Replicas: intPtr(1),
+						Template: actionsv1alpha1.RunnerTemplate{
+							Spec: actionsv1alpha1.RunnerSpec{
+								Repository: "test/valid",
+								Image:      "bar",
+								Env: []corev1.EnvVar{
+									{Name: "FOO", Value: "FOOVALUE"},
+								},
+							},
+						},
+					},
+				}
+
+				createRDErr := k8sClient.Create(ctx, rd)
+				Expect(createRDErr).NotTo(HaveOccurred(), "failed to create test RunnerReplicaSet resource")
+
+				Eventually(
+					func() (int, error) {
+						runnerSets := actionsv1alpha1.RunnerReplicaSetList{Items: []actionsv1alpha1.RunnerReplicaSet{}}
+
+						err := k8sClient.List(
+							ctx,
+							&runnerSets,
+							client.InNamespace(ns.Name),
+						)
+						if err != nil {
+							return 0, err
+						}
+
+						return len(runnerSets.Items), nil
+					},
+					time.Second*1, time.Millisecond*500).Should(BeEquivalentTo(1))
+
+				var rs17 *actionsv1alpha1.RunnerReplicaSet
+
+				Consistently(
+					func() (*metav1.LabelSelector, error) {
+						runnerSets := actionsv1alpha1.RunnerReplicaSetList{Items: []actionsv1alpha1.RunnerReplicaSet{}}
+
+						err := k8sClient.List(
+							ctx,
+							&runnerSets,
+							client.InNamespace(ns.Name),
+						)
+						if err != nil {
+							return nil, err
+						}
+						if len(runnerSets.Items) != 1 {
+							return nil, fmt.Errorf("runnerreplicasets is not 1 but %d", len(runnerSets.Items))
+						}
+
+						rs17 = &runnerSets.Items[0]
+
+						return runnerSets.Items[0].Spec.Selector, nil
+					},
+					time.Second*1, time.Millisecond*500).Should(Not(BeNil()))
+
+				// We simulate the old, pre 0.18.0 RunnerReplicaSet by updating it.
+				// I've tried to use controllerutil.Set{Owner,Controller}Reference and k8sClient.Create(rs17)
+				// but it didn't work due to missing RD UID, where UID is generated on K8s API server on k8sCLient.Create(rd)
+				rs17.Spec.Selector = nil
+
+				updateRSErr := k8sClient.Update(ctx, rs17)
+				Expect(updateRSErr).NotTo(HaveOccurred())
+
+				Eventually(
+					func() (*metav1.LabelSelector, error) {
+						runnerSets := actionsv1alpha1.RunnerReplicaSetList{Items: []actionsv1alpha1.RunnerReplicaSet{}}
+
+						err := k8sClient.List(
+							ctx,
+							&runnerSets,
+							client.InNamespace(ns.Name),
+						)
+						if err != nil {
+							return nil, err
+						}
+						if len(runnerSets.Items) != 1 {
+							return nil, fmt.Errorf("runnerreplicasets is not 1 but %d", len(runnerSets.Items))
+						}
+
+						return runnerSets.Items[0].Spec.Selector, nil
+					},
+					time.Second*1, time.Millisecond*500).Should(Not(BeNil()))
+			}
+		})
+
 	})
 })

controllers/runnerreplicaset_controller.go

@@ -68,8 +68,18 @@ func (r *RunnerReplicaSetReconciler) Reconcile(req ctrl.Request) (ctrl.Result, e
 		return ctrl.Result{}, nil
 	}
 
+	selector, err := metav1.LabelSelectorAsSelector(rs.Spec.Selector)
+	if err != nil {
+		return ctrl.Result{}, err
+	}
+	// Get the Runners managed by the target RunnerReplicaSet
 	var allRunners v1alpha1.RunnerList
-	if err := r.List(ctx, &allRunners, client.InNamespace(req.Namespace)); err != nil {
+	if err := r.List(
+		ctx,
+		&allRunners,
+		client.InNamespace(req.Namespace),
+		client.MatchingLabelsSelector{Selector: selector},
+	); err != nil {
 		if !kerrors.IsNotFound(err) {
 			return ctrl.Result{}, err
 		}
@@ -77,9 +87,14 @@ func (r *RunnerReplicaSetReconciler) Reconcile(req ctrl.Request) (ctrl.Result, e
 
 	var myRunners []v1alpha1.Runner
 
-	var available, ready int
+	var (
+		available int
+		ready     int
+	)
 
 	for _, r := range allRunners.Items {
+		// This guard is required to avoid the RunnerReplicaSet created by the controller v0.17.0 or before
+		// to not treat all the runners in the namespace as its children.
 		if metav1.IsControlledBy(&r, &rs) {
 			myRunners = append(myRunners, r)
 
@@ -99,14 +114,15 @@ func (r *RunnerReplicaSetReconciler) Reconcile(req ctrl.Request) (ctrl.Result, e
 		desired = 1
 	}
 
-	log.V(0).Info("debug", "desired", desired, "available", available)
-
 	if available > desired {
 		n := available - desired
 
-		// get runners that are currently not busy
-		var notBusy []v1alpha1.Runner
-		for _, runner := range myRunners {
+		log.V(0).Info(fmt.Sprintf("Deleting %d runners", n), "desired", desired, "available", available, "ready", ready)
+
+		// get runners that are currently offline/not busy/timed-out to register
+		var deletionCandidates []v1alpha1.Runner
+
+		for _, runner := range allRunners.Items {
 			busy, err := r.GitHubClient.IsRunnerBusy(ctx, runner.Spec.Enterprise, runner.Spec.Organization, runner.Spec.Repository, runner.Name)
 			if err != nil {
 				notRegistered := false
@@ -153,35 +169,37 @@ func (r *RunnerReplicaSetReconciler) Reconcile(req ctrl.Request) (ctrl.Result, e
 						"configuredRegistrationTimeout", registrationTimeout,
 					)
 
-					notBusy = append(notBusy, runner)
+					deletionCandidates = append(deletionCandidates, runner)
 				}
 
 				// offline runners should always be a great target for scale down
 				if offline {
-					notBusy = append(notBusy, runner)
+					deletionCandidates = append(deletionCandidates, runner)
 				}
 			} else if !busy {
-				notBusy = append(notBusy, runner)
+				deletionCandidates = append(deletionCandidates, runner)
 			}
 		}
 
-		if len(notBusy) < n {
-			n = len(notBusy)
+		if len(deletionCandidates) < n {
+			n = len(deletionCandidates)
 		}
 
 		for i := 0; i < n; i++ {
-			if err := r.Client.Delete(ctx, &notBusy[i]); client.IgnoreNotFound(err) != nil {
+			if err := r.Client.Delete(ctx, &deletionCandidates[i]); client.IgnoreNotFound(err) != nil {
 				log.Error(err, "Failed to delete runner resource")
 
 				return ctrl.Result{}, err
 			}
 
-			r.Recorder.Event(&rs, corev1.EventTypeNormal, "RunnerDeleted", fmt.Sprintf("Deleted runner '%s'", notBusy[i].Name))
-			log.Info("Deleted runner", "runnerreplicaset", rs.ObjectMeta.Name)
+			r.Recorder.Event(&rs, corev1.EventTypeNormal, "RunnerDeleted", fmt.Sprintf("Deleted runner '%s'", deletionCandidates[i].Name))
+			log.Info("Deleted runner")
 		}
 	} else if desired > available {
 		n := desired - available
 
+		log.V(0).Info(fmt.Sprintf("Creating %d runner(s)", n), "desired", desired, "available", available, "ready", ready)
+
 		for i := 0; i < n; i++ {
 			newRunner, err := r.newRunner(rs)
 			if err != nil {

controllers/runnerreplicaset_controller_test.go

@@ -47,7 +47,9 @@ func SetupTest(ctx context.Context) *corev1.Namespace {
 		err := k8sClient.Create(ctx, ns)
 		Expect(err).NotTo(HaveOccurred(), "failed to create test namespace")
 
-		mgr, err := ctrl.NewManager(cfg, ctrl.Options{})
+		mgr, err := ctrl.NewManager(cfg, ctrl.Options{
+			Namespace: ns.Name,
+		})
 		Expect(err).NotTo(HaveOccurred(), "failed to create manager")
 
 		runnersList = fake.NewRunnersList()
@@ -115,9 +117,19 @@ var _ = Context("Inside of a new namespace", func() {
 					},
 					Spec: actionsv1alpha1.RunnerReplicaSetSpec{
 						Replicas: intPtr(1),
+						Selector: &metav1.LabelSelector{
+							MatchLabels: map[string]string{
+								"foo": "bar",
+							},
+						},
 						Template: actionsv1alpha1.RunnerTemplate{
+							ObjectMeta: metav1.ObjectMeta{
+								Labels: map[string]string{
+									"foo": "bar",
+								},
+							},
 							Spec: actionsv1alpha1.RunnerSpec{
-								Repository: "foo/bar",
+								Repository: "test/valid",
 								Image:      "bar",
 								Env: []corev1.EnvVar{
 									{Name: "FOO", Value: "FOOVALUE"},
@@ -135,9 +147,26 @@ var _ = Context("Inside of a new namespace", func() {
 
 				Eventually(
 					func() int {
-						err := k8sClient.List(ctx, &runners, client.InNamespace(ns.Name))
+						selector, err := metav1.LabelSelectorAsSelector(
+							&metav1.LabelSelector{
+								MatchLabels: map[string]string{
+									"foo": "bar",
+								},
+							},
+						)
+						if err != nil {
+							logf.Log.Error(err, "failed to create labelselector")
+							return -1
+						}
+						err = k8sClient.List(
+							ctx,
+							&runners,
+							client.InNamespace(ns.Name),
+							client.MatchingLabelsSelector{Selector: selector},
+						)
 						if err != nil {
 							logf.Log.Error(err, "list runners")
+							return -1
 						}
 
 						for i, runner := range runners.Items {
@@ -176,7 +205,23 @@ var _ = Context("Inside of a new namespace", func() {
 
 				Eventually(
 					func() int {
-						err := k8sClient.List(ctx, &runners, client.InNamespace(ns.Name))
+						selector, err := metav1.LabelSelectorAsSelector(
+							&metav1.LabelSelector{
+								MatchLabels: map[string]string{
+									"foo": "bar",
+								},
+							},
+						)
+						if err != nil {
+							logf.Log.Error(err, "failed to create labelselector")
+							return -1
+						}
+						err = k8sClient.List(
+							ctx,
+							&runners,
+							client.InNamespace(ns.Name),
+							client.MatchingLabelsSelector{Selector: selector},
+						)
 						if err != nil {
 							logf.Log.Error(err, "list runners")
 						}
@@ -220,6 +265,7 @@ var _ = Context("Inside of a new namespace", func() {
 						err := k8sClient.List(ctx, &runners, client.InNamespace(ns.Name))
 						if err != nil {
 							logf.Log.Error(err, "list runners")
+							return -1
 						}
 
 						for i, runner := range runners.Items {

controllers/suite_test.go

@@ -55,9 +55,17 @@ func TestAPIs(t *testing.T) {
 var _ = BeforeSuite(func(done Done) {
 	logf.SetLogger(zap.LoggerTo(GinkgoWriter, true))
 
+	var apiServerFlags []string
+
+	apiServerFlags = append(apiServerFlags, envtest.DefaultKubeAPIServerFlags...)
+	// Avoids the following error:
+	// 2021-03-19T15:14:11.673+0900    ERROR   controller-runtime.controller   Reconciler error      {"controller": "testns-tvjzjrunner", "request": "testns-gdnyx/example-runnerdeploy-zps4z-j5562", "error": "Pod \"example-runnerdeploy-zps4z-j5562\" is invalid: [spec.containers[1].image: Required value, spec.containers[1].securityContext.privileged: Forbidden: disallowed by cluster policy]"}
+	apiServerFlags = append(apiServerFlags, "--allow-privileged=true")
+
 	By("bootstrapping test environment")
 	testEnv = &envtest.Environment{
 		CRDDirectoryPaths:  []string{filepath.Join("..", "config", "crd", "bases")},
+		KubeAPIServerFlags: apiServerFlags,
 	}
 
 	var err error

github/github.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"net/http"
 	"net/url"
+	"os"
 	"strings"
 	"sync"
 	"time"
@@ -39,10 +40,20 @@ func (c *Config) NewClient() (*Client, error) {
 	if len(c.Token) > 0 {
 		transport = oauth2.NewClient(context.Background(), oauth2.StaticTokenSource(&oauth2.Token{AccessToken: c.Token})).Transport
 	} else {
-		tr, err := ghinstallation.NewKeyFromFile(http.DefaultTransport, c.AppID, c.AppInstallationID, c.AppPrivateKey)
+		var tr *ghinstallation.Transport
+
+		if _, err := os.Stat(c.AppPrivateKey); err == nil {
+			tr, err = ghinstallation.NewKeyFromFile(http.DefaultTransport, c.AppID, c.AppInstallationID, c.AppPrivateKey)
 			if err != nil {
-			return nil, fmt.Errorf("authentication failed: %v", err)
+				return nil, fmt.Errorf("authentication failed: using private key at %s: %v", c.AppPrivateKey, err)
 			}
+		} else {
+			tr, err = ghinstallation.New(http.DefaultTransport, c.AppID, c.AppInstallationID, []byte(c.AppPrivateKey))
+			if err != nil {
+				return nil, fmt.Errorf("authentication failed: using private key of size %d (%s...): %v", len(c.AppPrivateKey), strings.Split(c.AppPrivateKey, "\n")[0], err)
+			}
+		}
+
 		if len(c.EnterpriseURL) > 0 {
 			githubAPIURL, err := getEnterpriseApiUrl(c.EnterpriseURL)
 			if err != nil {
@@ -147,7 +158,7 @@ func (c *Client) ListRunners(ctx context.Context, enterprise, org, repo string)
 
 	var runners []*github.Runner
 
-	opts := github.ListOptions{PerPage: 10}
+	opts := github.ListOptions{PerPage: 100}
 	for {
 		list, res, err := c.listRunners(ctx, enterprise, owner, repo, &opts)
 
@@ -211,8 +222,6 @@ func (c *Client) listRunners(ctx context.Context, enterprise, org, repo string,
 }
 
 func (c *Client) ListRepositoryWorkflowRuns(ctx context.Context, user string, repoName string) ([]*github.WorkflowRun, error) {
-	c.Client.Actions.ListRepositoryWorkflowRuns(ctx, user, repoName, nil)
-
 	queued, err := c.listRepositoryWorkflowRuns(ctx, user, repoName, "queued")
 	if err != nil {
 		return nil, fmt.Errorf("listing queued workflow runs: %w", err)
@@ -232,8 +241,6 @@ func (c *Client) ListRepositoryWorkflowRuns(ctx context.Context, user string, re
 }
 
 func (c *Client) listRepositoryWorkflowRuns(ctx context.Context, user string, repoName, status string) ([]*github.WorkflowRun, error) {
-	c.Client.Actions.ListRepositoryWorkflowRuns(ctx, user, repoName, nil)
-
 	var workflowRuns []*github.WorkflowRun
 
 	opts := github.ListWorkflowRunsOptions{

main.go

@@ -42,7 +42,7 @@ const (
 
 var (
 	scheme = runtime.NewScheme()
-	setupLog = ctrl.Log.WithName("setup")
+	log    = ctrl.Log.WithName("actions-runner-controller")
 )
 
 func init() {
@@ -63,6 +63,7 @@ func main() {
 
 		runnerImage string
 		dockerImage string
+		namespace   string
 
 		commonRunnerLabels commaSeparatedStringSlice
 	)
@@ -84,6 +85,7 @@ func main() {
 	flag.StringVar(&c.AppPrivateKey, "github-app-private-key", c.AppPrivateKey, "The path of a private key file to authenticate as a GitHub App")
 	flag.DurationVar(&syncPeriod, "sync-period", 10*time.Minute, "Determines the minimum frequency at which K8s resources managed by this controller are reconciled. When you use autoscaling, set to a lower value like 10 minute, because this corresponds to the minimum time to react on demand change")
 	flag.Var(&commonRunnerLabels, "common-runner-labels", "Runner labels in the K1=V1,K2=V2,... format that are inherited all the runners created by the controller. See https://github.com/summerwind/actions-runner-controller/issues/321 for more information")
+	flag.StringVar(&namespace, "watch-namespace", "", "The namespace to watch for custom resources. Set to empty for letting it watch for all namespaces.")
 	flag.Parse()
 
 	logger := zap.New(func(o *zap.Options) {
@@ -104,15 +106,16 @@ func main() {
 		LeaderElection:     enableLeaderElection,
 		Port:               9443,
 		SyncPeriod:         &syncPeriod,
+		Namespace:          namespace,
 	})
 	if err != nil {
-		setupLog.Error(err, "unable to start manager")
+		log.Error(err, "unable to start manager")
 		os.Exit(1)
 	}
 
 	runnerReconciler := &controllers.RunnerReconciler{
 		Client:       mgr.GetClient(),
-		Log:          ctrl.Log.WithName("controllers").WithName("Runner"),
+		Log:          log.WithName("runner"),
 		Scheme:       mgr.GetScheme(),
 		GitHubClient: ghClient,
 		RunnerImage:  runnerImage,
@@ -120,64 +123,64 @@ func main() {
 	}
 
 	if err = runnerReconciler.SetupWithManager(mgr); err != nil {
-		setupLog.Error(err, "unable to create controller", "controller", "Runner")
+		log.Error(err, "unable to create controller", "controller", "Runner")
 		os.Exit(1)
 	}
 
 	runnerSetReconciler := &controllers.RunnerReplicaSetReconciler{
 		Client:       mgr.GetClient(),
-		Log:          ctrl.Log.WithName("controllers").WithName("RunnerReplicaSet"),
+		Log:          log.WithName("runnerreplicaset"),
 		Scheme:       mgr.GetScheme(),
 		GitHubClient: ghClient,
 	}
 
 	if err = runnerSetReconciler.SetupWithManager(mgr); err != nil {
-		setupLog.Error(err, "unable to create controller", "controller", "RunnerReplicaSet")
+		log.Error(err, "unable to create controller", "controller", "RunnerReplicaSet")
 		os.Exit(1)
 	}
 
 	runnerDeploymentReconciler := &controllers.RunnerDeploymentReconciler{
 		Client:             mgr.GetClient(),
-		Log:                ctrl.Log.WithName("controllers").WithName("RunnerDeployment"),
+		Log:                log.WithName("runnerdeployment"),
 		Scheme:             mgr.GetScheme(),
 		CommonRunnerLabels: commonRunnerLabels,
 	}
 
 	if err = runnerDeploymentReconciler.SetupWithManager(mgr); err != nil {
-		setupLog.Error(err, "unable to create controller", "controller", "RunnerDeployment")
+		log.Error(err, "unable to create controller", "controller", "RunnerDeployment")
 		os.Exit(1)
 	}
 
 	horizontalRunnerAutoscaler := &controllers.HorizontalRunnerAutoscalerReconciler{
 		Client:        mgr.GetClient(),
-		Log:           ctrl.Log.WithName("controllers").WithName("HorizontalRunnerAutoscaler"),
+		Log:           log.WithName("horizontalrunnerautoscaler"),
 		Scheme:        mgr.GetScheme(),
 		GitHubClient:  ghClient,
 		CacheDuration: syncPeriod - 10*time.Second,
 	}
 
 	if err = horizontalRunnerAutoscaler.SetupWithManager(mgr); err != nil {
-		setupLog.Error(err, "unable to create controller", "controller", "HorizontalRunnerAutoscaler")
+		log.Error(err, "unable to create controller", "controller", "HorizontalRunnerAutoscaler")
 		os.Exit(1)
 	}
 
 	if err = (&actionsv1alpha1.Runner{}).SetupWebhookWithManager(mgr); err != nil {
-		setupLog.Error(err, "unable to create webhook", "webhook", "Runner")
+		log.Error(err, "unable to create webhook", "webhook", "Runner")
 		os.Exit(1)
 	}
 	if err = (&actionsv1alpha1.RunnerDeployment{}).SetupWebhookWithManager(mgr); err != nil {
-		setupLog.Error(err, "unable to create webhook", "webhook", "RunnerDeployment")
+		log.Error(err, "unable to create webhook", "webhook", "RunnerDeployment")
 		os.Exit(1)
 	}
 	if err = (&actionsv1alpha1.RunnerReplicaSet{}).SetupWebhookWithManager(mgr); err != nil {
-		setupLog.Error(err, "unable to create webhook", "webhook", "RunnerReplicaSet")
+		log.Error(err, "unable to create webhook", "webhook", "RunnerReplicaSet")
 		os.Exit(1)
 	}
 	// +kubebuilder:scaffold:builder
 
-	setupLog.Info("starting manager")
+	log.Info("starting manager")
 	if err := mgr.Start(ctrl.SetupSignalHandler()); err != nil {
-		setupLog.Error(err, "problem running manager")
+		log.Error(err, "problem running manager")
 		os.Exit(1)
 	}
 }

pkg/actionsglob/README.md

@@ -0,0 +1,8 @@
+This package is an implementation of glob that is intended to simulate the behaviour of 
+https://github.com/actions/toolkit/tree/master/packages/glob in many cases.
+
+This isn't a complete reimplementation of the referenced nodejs package.
+
+Differences:
+
+- This package doesn't implement `**`

pkg/actionsglob/actionsglob.go

@@ -0,0 +1,78 @@
+package actionsglob
+
+import (
+	"fmt"
+	"strings"
+)
+
+func Match(pat string, s string) bool {
+	if len(pat) == 0 {
+		panic(fmt.Sprintf("unexpected length of pattern: %d", len(pat)))
+	}
+
+	var inverse bool
+
+	if pat[0] == '!' {
+		pat = pat[1:]
+		inverse = true
+	}
+
+	tokens := strings.SplitAfter(pat, "*")
+
+	var wildcardInHead bool
+
+	for i := 0; i < len(tokens); i++ {
+		p := tokens[i]
+
+		if p == "" {
+			s = ""
+			break
+		}
+
+		if p == "*" {
+			if i == len(tokens)-1 {
+				s = ""
+				break
+			}
+
+			wildcardInHead = true
+
+			continue
+		}
+
+		wildcardInTail := p[len(p)-1] == '*'
+		if wildcardInTail {
+			p = p[:len(p)-1]
+		}
+
+		subs := strings.SplitN(s, p, 2)
+
+		if len(subs) == 0 {
+			break
+		}
+
+		if subs[0] != "" {
+			if !wildcardInHead {
+				break
+			}
+		}
+
+		if subs[1] != "" {
+			if !wildcardInTail {
+				break
+			}
+		}
+
+		s = subs[1]
+
+		wildcardInHead = wildcardInTail
+	}
+
+	r := s == ""
+
+	if inverse {
+		r = !r
+	}
+
+	return r
+}

pkg/actionsglob/match_test.go

@@ -0,0 +1,214 @@
+package actionsglob
+
+import (
+	"testing"
+)
+
+func TestMatch(t *testing.T) {
+	type testcase struct {
+		Pattern, Target string
+		Want            bool
+	}
+
+	run := func(t *testing.T, tc testcase) {
+		t.Helper()
+
+		got := Match(tc.Pattern, tc.Target)
+
+		if got != tc.Want {
+			t.Errorf("%s against %s: want %v, got %v", tc.Pattern, tc.Target, tc.Want, got)
+		}
+	}
+
+	t.Run("foo == foo", func(t *testing.T) {
+		run(t, testcase{
+			Pattern: "foo",
+			Target:  "foo",
+			Want:    true,
+		})
+	})
+
+	t.Run("!foo == foo", func(t *testing.T) {
+		run(t, testcase{
+			Pattern: "!foo",
+			Target:  "foo",
+			Want:    false,
+		})
+	})
+
+	t.Run("foo == foo1", func(t *testing.T) {
+		run(t, testcase{
+			Pattern: "foo",
+			Target:  "foo1",
+			Want:    false,
+		})
+	})
+
+	t.Run("!foo == foo1", func(t *testing.T) {
+		run(t, testcase{
+			Pattern: "!foo",
+			Target:  "foo1",
+			Want:    true,
+		})
+	})
+
+	t.Run("*foo == foo", func(t *testing.T) {
+		run(t, testcase{
+			Pattern: "*foo",
+			Target:  "foo",
+			Want:    true,
+		})
+	})
+
+	t.Run("!*foo == foo", func(t *testing.T) {
+		run(t, testcase{
+			Pattern: "!*foo",
+			Target:  "foo",
+			Want:    false,
+		})
+	})
+
+	t.Run("*foo == 1foo", func(t *testing.T) {
+		run(t, testcase{
+			Pattern: "*foo",
+			Target:  "1foo",
+			Want:    true,
+		})
+	})
+
+	t.Run("!*foo == 1foo", func(t *testing.T) {
+		run(t, testcase{
+			Pattern: "!*foo",
+			Target:  "1foo",
+			Want:    false,
+		})
+	})
+
+	t.Run("*foo == foo1", func(t *testing.T) {
+		run(t, testcase{
+			Pattern: "*foo",
+			Target:  "foo1",
+			Want:    false,
+		})
+	})
+
+	t.Run("!*foo == foo1", func(t *testing.T) {
+		run(t, testcase{
+			Pattern: "!*foo",
+			Target:  "foo1",
+			Want:    true,
+		})
+	})
+
+	t.Run("*foo* == foo1", func(t *testing.T) {
+		run(t, testcase{
+			Pattern: "*foo*",
+			Target:  "foo1",
+			Want:    true,
+		})
+	})
+
+	t.Run("!*foo* == foo1", func(t *testing.T) {
+		run(t, testcase{
+			Pattern: "!*foo*",
+			Target:  "foo1",
+			Want:    false,
+		})
+	})
+
+	t.Run("*foo == foobar", func(t *testing.T) {
+		run(t, testcase{
+			Pattern: "*foo",
+			Target:  "foobar",
+			Want:    false,
+		})
+	})
+
+	t.Run("!*foo == foobar", func(t *testing.T) {
+		run(t, testcase{
+			Pattern: "!*foo",
+			Target:  "foobar",
+			Want:    true,
+		})
+	})
+
+	t.Run("*foo* == foobar", func(t *testing.T) {
+		run(t, testcase{
+			Pattern: "*foo*",
+			Target:  "foobar",
+			Want:    true,
+		})
+	})
+
+	t.Run("!*foo* == foobar", func(t *testing.T) {
+		run(t, testcase{
+			Pattern: "!*foo*",
+			Target:  "foobar",
+			Want:    false,
+		})
+	})
+
+	t.Run("foo* == foo", func(t *testing.T) {
+		run(t, testcase{
+			Pattern: "foo*",
+			Target:  "foo",
+			Want:    true,
+		})
+	})
+
+	t.Run("!foo* == foo", func(t *testing.T) {
+		run(t, testcase{
+			Pattern: "!foo*",
+			Target:  "foo",
+			Want:    false,
+		})
+	})
+
+	t.Run("foo* == foobar", func(t *testing.T) {
+		run(t, testcase{
+			Pattern: "foo*",
+			Target:  "foobar",
+			Want:    true,
+		})
+	})
+
+	t.Run("!foo* == foobar", func(t *testing.T) {
+		run(t, testcase{
+			Pattern: "!foo*",
+			Target:  "foobar",
+			Want:    false,
+		})
+	})
+
+	t.Run("foo (* == foo ( 1 / 2 )", func(t *testing.T) {
+		run(t, testcase{
+			Pattern: "foo (*",
+			Target:  "foo ( 1 / 2 )",
+			Want:    true,
+		})
+	})
+
+	t.Run("!foo (* == foo ( 1 / 2 )", func(t *testing.T) {
+		run(t, testcase{
+			Pattern: "!foo (*",
+			Target:  "foo ( 1 / 2 )",
+			Want:    false,
+		})
+	})
+
+	t.Run("actions-*-metrics == actions-workflow-metrics", func(t *testing.T) {
+		run(t, testcase{
+			Pattern: "actions-*-metrics",
+			Target:  "actions-workflow-metrics",
+			Want:    true,
+		})
+	})
+
+	t.Run("!actions-*-metrics == actions-workflow-metrics", func(t *testing.T) {
+		run(t, testcase{
+			Pattern: "!actions-*-metrics",
+			Target:  "actions-workflow-metrics",
+			Want:    false,
+		})
+	})
+}

runner/Dockerfile

@@ -37,6 +37,7 @@ RUN apt update -y \
   wget \
   zip \
   zstd \
+  && cd /usr/bin && ln -sf python3 python \
   && rm -rf /var/lib/apt/lists/*
 
 RUN export ARCH=$(echo ${TARGETPLATFORM} | cut -d / -f2) \

runner/dindrunner.Dockerfile

@@ -21,6 +21,7 @@ RUN apt update \
     netcat \
     openssh-client \
     parallel \
+    python-is-python3 \
     rsync \
     shellcheck \
     sudo \

runner/entrypoint.sh

@@ -29,21 +29,13 @@ else
   exit 1
 fi
 
-if [ -n "${RUNNER_WORKDIR}" ]; then
-  WORKDIR_ARG="--work ${RUNNER_WORKDIR}"
-fi
-
-if [ -n "${RUNNER_LABELS}" ]; then
-  LABEL_ARG="--labels ${RUNNER_LABELS}"
-fi
-
 if [ -z "${RUNNER_TOKEN}" ]; then
   echo "RUNNER_TOKEN must be set" 1>&2
   exit 1
 fi
 
-if [ -z "${RUNNER_REPO}" ] && [ -n "${RUNNER_ORG}" ] && [ -n "${RUNNER_GROUP}" ];then
-  RUNNER_GROUP_ARG="--runnergroup ${RUNNER_GROUP}"
+if [ -z "${RUNNER_REPO}" ] && [ -n "${RUNNER_GROUP}" ];then
+  RUNNER_GROUPS=${RUNNER_GROUP}
 fi
 
 # Hack due to https://github.com/summerwind/actions-runner-controller/issues/252#issuecomment-758338483
@@ -56,7 +48,14 @@ sudo chown -R runner:docker /runner
 mv /runnertmp/* /runner/
 
 cd /runner
-./config.sh --unattended --replace --name "${RUNNER_NAME}" --url "${GITHUB_URL}${ATTACH}" --token "${RUNNER_TOKEN}" ${RUNNER_GROUP_ARG} ${LABEL_ARG} ${WORKDIR_ARG}
+./config.sh --unattended --replace \
+  --name "${RUNNER_NAME}" \
+  --url "${GITHUB_URL}${ATTACH}" \
+  --token "${RUNNER_TOKEN}" \
+  --runnergroup "${RUNNER_GROUPS}" \
+  --labels "${RUNNER_LABELS}" \
+  --work "${RUNNER_WORKDIR}"
+
 mkdir ./externals
 # Hack due to the DinD volumes
 mv ./externalstmp/* ./externals/

runner/startup.sh

@@ -17,6 +17,34 @@ function wait_for_process () {
     return 0
 }
 
+sudo /bin/bash <<SCRIPT
+mkdir -p /etc/docker
+
+cat <<EOS > /etc/docker/daemon.json
+{
+EOS
+
+if [ -n "${MTU}" ]; then
+cat <<EOS >> /etc/docker/daemon.json
+  "mtu": ${MTU}
+EOS
+# See https://docs.docker.com/engine/security/rootless/
+echo "environment=DOCKERD_ROOTLESS_ROOTLESSKIT_MTU=${MTU}" >> /etc/supervisor/conf.d/dockerd.conf
+fi
+
+cat <<EOS >> /etc/docker/daemon.json
+}
+EOS
+SCRIPT
+
+INFO "Using /etc/docker/daemon.json with the following content"
+
+cat /etc/docker/daemon.json
+
+INFO "Using /etc/supervisor/conf.d/dockerd.conf with the following content"
+
+cat /etc/supervisor/conf.d/dockerd.conf
+
 INFO "Starting supervisor"
 sudo /usr/bin/supervisord -n >> /dev/null 2>&1 &
 
@@ -27,11 +55,17 @@ for process in "${processes[@]}"; do
     wait_for_process "$process"
     if [ $? -ne 0 ]; then
         ERROR "$process is not running after max time"
+        ERROR "Dumping /var/log/dockerd.err.log to help investigation"
+        cat /var/log/dockerd.err.log
         exit 1
     else 
         INFO "$process is running"
     fi
 done
 
+if [ -n "${MTU}" ]; then
+  ifconfig docker0 mtu ${MTU} up
+fi
+
 # Wait processes to be running
 entrypoint.sh