scale{Up,Down}Adjustment to add/remove constant number of replicas on scaling (#315)

* `scale{Up,Down}Adjustment` to add/remove constant number of replicas on scaling

Ref #305

* Bump chart version

.github/workflows/build-and-release-runners.yml

@@ -1,3 +1,5 @@
+name: Build and Release Runners
+
 on:
   pull_request:
     branches:
@@ -14,6 +16,8 @@ on:
       - runner/dindrunner.Dockerfile
       - runner/entrypoint.sh
       - .github/workflows/build-runner.yml
+  release:
+    types: [published]
 name: Runner
 jobs:
   build:
@@ -27,10 +31,14 @@ jobs:
           - name: actions-runner-dind
             dockerfile: dindrunner.Dockerfile
     env:
-      RUNNER_VERSION: 2.275.1
+      RUNNER_VERSION: 2.276.1
       DOCKER_VERSION: 19.03.12
       DOCKERHUB_USERNAME: ${{ github.repository_owner }}
     steps:
+      - name: Set outputs
+        id: vars
+        run: echo ::set-output name=sha_short::${GITHUB_SHA::7}
+
       - name: Checkout
         uses: actions/checkout@v2
 
@@ -49,16 +57,35 @@ jobs:
           username: ${{ github.repository_owner }}
           password: ${{ secrets.DOCKER_ACCESS_TOKEN }}
 
-      - name: Build [and Push]
+      # Considered unstable builds
+      # Mutable (no sha) and immutable (include sha) tags are created, see Issue 285 and PR 286 for why
+      - name: Build and push canary builds
         uses: docker/build-push-action@v2
         with:
           context: ./runner
           file: ./runner/${{ matrix.dockerfile }}
           platforms: linux/amd64,linux/arm64
-          push: ${{ github.event_name != 'pull_request' }}
+          push: ${{ github.event_name != 'pull_request' && github.event_name != 'release' }}
+          build-args: |
+            RUNNER_VERSION=${{ env.RUNNER_VERSION }}
+            DOCKER_VERSION=${{ env.DOCKER_VERSION }}
+          tags: |
+            ${{ env.DOCKERHUB_USERNAME }}/${{ matrix.name }}:v${{ env.RUNNER_VERSION }}-canary
+            ${{ env.DOCKERHUB_USERNAME }}/${{ matrix.name }}:v${{ env.RUNNER_VERSION }}-canary-${{ steps.vars.outputs.sha_short }}
+
+      # Considered stable builds
+      # Mutable (no sha) and immutable (include sha) tags are created, see Issue 285 and PR 286 for why
+      - name: Build and push release builds
+        uses: docker/build-push-action@v2
+        with:
+          context: ./runner
+          file: ./runner/${{ matrix.dockerfile }}
+          platforms: linux/amd64,linux/arm64
+          push: ${{ github.event_name == 'release' }}
           build-args: |
             RUNNER_VERSION=${{ env.RUNNER_VERSION }}
             DOCKER_VERSION=${{ env.DOCKER_VERSION }}
           tags: |
             ${{ env.DOCKERHUB_USERNAME }}/${{ matrix.name }}:v${{ env.RUNNER_VERSION }}
+            ${{ env.DOCKERHUB_USERNAME }}/${{ matrix.name }}:v${{ env.RUNNER_VERSION }}-${{ steps.vars.outputs.sha_short }}
             ${{ env.DOCKERHUB_USERNAME }}/${{ matrix.name }}:latest

.github/workflows/on-push-lint-charts.yml

@@ -0,0 +1,75 @@
+name: Lint and Test Charts
+
+on:
+  push:
+    paths:
+      - 'charts/**'
+      - '.github/**'
+  workflow_dispatch:
+
+env:
+  KUBE_SCORE_VERSION: 1.10.0
+  HELM_VERSION: v3.4.1
+
+jobs:
+  lint-test:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+        with:
+          fetch-depth: 0
+
+      - name: Set up Helm
+        uses: azure/setup-helm@v1
+        with:
+          version: ${{ env.HELM_VERSION }}
+
+      - name: Set up kube-score
+        run: |
+          wget https://github.com/zegl/kube-score/releases/download/v${{ env.KUBE_SCORE_VERSION }}/kube-score_${{ env.KUBE_SCORE_VERSION }}_linux_amd64 -O kube-score
+          chmod 755 kube-score
+
+      - name: Kube-score generated manifests
+        run: helm template  --values charts/.ci/values-kube-score.yaml charts/* | ./kube-score score -
+              --ignore-test pod-networkpolicy
+              --ignore-test deployment-has-poddisruptionbudget
+              --ignore-test deployment-has-host-podantiaffinity
+              --ignore-test container-security-context
+              --ignore-test pod-probes
+              --ignore-test container-image-tag
+              --enable-optional-test container-security-context-privileged
+              --enable-optional-test container-security-context-readonlyrootfilesystem
+
+      # python is a requirement for the chart-testing action below (supports yamllint among other tests)
+      - uses: actions/setup-python@v2
+        with:
+          python-version: 3.7
+
+      - name: Set up chart-testing
+        uses: helm/chart-testing-action@v2.0.1
+
+      - name: Run chart-testing (list-changed)
+        id: list-changed
+        run: |
+          changed=$(ct list-changed --config charts/.ci/ct-config.yaml)
+          if [[ -n "$changed" ]]; then
+            echo "::set-output name=changed::true"
+          fi
+
+      - name: Run chart-testing (lint)
+        run: ct lint --config charts/.ci/ct-config.yaml
+
+      - name: Create kind cluster
+        uses: helm/kind-action@v1.0.0
+        if: steps.list-changed.outputs.changed == 'true'
+
+      # We need cert-manager already installed in the cluster because we assume the CRDs exist
+      - name: Install cert-manager
+        run: |
+          helm repo add jetstack https://charts.jetstack.io --force-update
+          helm install cert-manager jetstack/cert-manager --set installCRDs=true --wait
+        if: steps.list-changed.outputs.changed == 'true'
+
+      - name: Run chart-testing (install)
+        run: ct install --config charts/.ci/ct-config.yaml

.github/workflows/on-push-master-publish-chart.yml

@@ -0,0 +1,101 @@
+name: Publish helm chart
+
+on:
+  push:
+    branches:
+      - master
+      - main # assume that the branch name may change in future
+    paths:
+      - 'charts/**'
+      - '.github/**'
+  workflow_dispatch:
+
+env:
+  KUBE_SCORE_VERSION: 1.10.0
+  HELM_VERSION: v3.4.1
+
+jobs:
+  lint-chart:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+        with:
+          fetch-depth: 0
+
+      - name: Set up Helm
+        uses: azure/setup-helm@v1
+        with:
+          version: ${{ env.HELM_VERSION }}
+
+      - name: Set up kube-score
+        run: |
+          wget https://github.com/zegl/kube-score/releases/download/v${{ env.KUBE_SCORE_VERSION }}/kube-score_${{ env.KUBE_SCORE_VERSION }}_linux_amd64 -O kube-score
+          chmod 755 kube-score
+
+      - name: Kube-score generated manifests
+        run: helm template  --values charts/.ci/values-kube-score.yaml charts/* | ./kube-score score -
+              --ignore-test pod-networkpolicy
+              --ignore-test deployment-has-poddisruptionbudget
+              --ignore-test deployment-has-host-podantiaffinity
+              --ignore-test container-security-context
+              --ignore-test pod-probes
+              --ignore-test container-image-tag
+              --enable-optional-test container-security-context-privileged
+              --enable-optional-test container-security-context-readonlyrootfilesystem
+
+      # python is a requirement for the chart-testing action below (supports yamllint among other tests)
+      - uses: actions/setup-python@v2
+        with:
+          python-version: 3.7
+
+      - name: Set up chart-testing
+        uses: helm/chart-testing-action@v2.0.1
+
+      - name: Run chart-testing (list-changed)
+        id: list-changed
+        run: |
+          changed=$(ct list-changed --config charts/.ci/ct-config.yaml)
+          if [[ -n "$changed" ]]; then
+            echo "::set-output name=changed::true"
+          fi
+
+      - name: Run chart-testing (lint)
+        run: ct lint --config charts/.ci/ct-config.yaml
+
+      - name: Create kind cluster
+        uses: helm/kind-action@v1.0.0
+        if: steps.list-changed.outputs.changed == 'true'
+
+      # We need cert-manager already installed in the cluster because we assume the CRDs exist
+      - name: Install cert-manager
+        run: |
+          helm repo add jetstack https://charts.jetstack.io --force-update
+          helm install cert-manager jetstack/cert-manager --set installCRDs=true --wait
+        if: steps.list-changed.outputs.changed == 'true'
+
+      - name: Run chart-testing (install)
+        run: ct install --config charts/.ci/ct-config.yaml
+        if: steps.list-changed.outputs.changed == 'true'
+
+  publish-chart:
+
+    runs-on: ubuntu-latest
+    needs: lint-chart
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+        with:
+          fetch-depth: 0
+
+      - name: Configure Git
+        run: |
+          git config user.name "$GITHUB_ACTOR"
+          git config user.email "$GITHUB_ACTOR@users.noreply.github.com"
+
+      - name: Run chart-releaser
+        uses: helm/chart-releaser-action@v1.1.0
+        env:
+          CR_TOKEN: "${{ secrets.GITHUB_TOKEN }}"
+

.github/workflows/release.yml

@@ -9,6 +9,10 @@ jobs:
     env:
       DOCKERHUB_USERNAME: ${{ github.repository_owner }}
     steps:
+      - name: Set outputs
+        id: vars
+        run: echo ::set-output name=sha_short::${GITHUB_SHA::7}
+
       - name: Checkout
         uses: actions/checkout@v2
 
@@ -52,5 +56,7 @@ jobs:
           file: Dockerfile
           platforms: linux/amd64,linux/arm64
           push: true
-          tags: ${{ env.DOCKERHUB_USERNAME }}/actions-runner-controller:${{ env.VERSION }} 
+          tags: |
+            ${{ env.DOCKERHUB_USERNAME }}/actions-runner-controller:${{ env.VERSION }}
+            ${{ env.DOCKERHUB_USERNAME }}/actions-runner-controller:${{ env.VERSION }}-${{ steps.vars.outputs.sha_short }}
 

.gitignore

@@ -26,3 +26,6 @@ bin
 
 .envrc
 *.pem
+
+# OS
+.DS_STORE

Dockerfile

@@ -22,7 +22,8 @@ COPY . .
 RUN export GOOS=$(echo ${TARGETPLATFORM} | cut -d / -f1) && \
   export GOARCH=$(echo ${TARGETPLATFORM} | cut -d / -f2) && \
   GOARM=$(echo ${TARGETPLATFORM} | cut -d / -f3 | cut -c2-) && \
-  go build -a -o manager main.go
+  go build -a -o manager main.go && \
+  go build -a -o github-webhook-server ./cmd/githubwebhookserver
 
 # Use distroless as minimal base image to package the manager binary
 # Refer to https://github.com/GoogleContainerTools/distroless for more details
@@ -31,6 +32,7 @@ FROM gcr.io/distroless/static:nonroot
 WORKDIR /
 
 COPY --from=builder /workspace/manager .
+COPY --from=builder /workspace/github-webhook-server .
 
 USER nonroot:nonroot
 

README.md

@@ -2,6 +2,30 @@
 
 This controller operates self-hosted runners for GitHub Actions on your Kubernetes cluster.
 
+ToC:
+
+- [Motivation](#motivation)
+- [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)
+- [Usage](#usage)
+  - [Repository Runners](#repository-runners)
+  - [Organization Runners](#organization-runners)
+  - [Runner Deployments](#runnerdeployments)
+    - [Autoscaling](#autoscaling)
+      - [Faster Autoscaling with GitHub Webhook](#faster-autoscaling-with-github-webhook)
+  - [Runner with DinD](#runner-with-dind)
+  - [Additional tweaks](#additional-tweaks)
+  - [Runner labels](#runner-labels)
+  - [Runer 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)
+- [Developing](#developing)
+- [Alternatives](#alternatives)
+
 ## Motivation
 
 [GitHub Actions](https://github.com/features/actions) is a very useful tool for automating development. GitHub Actions jobs are run in the cloud by default, but you may want to run your jobs in your environment. [Self-hosted runner](https://github.com/actions/runner) can be used for such use cases, but requires the provisioning and configuration of a virtual machine instance. Instead if you already have a Kubernetes cluster, it makes more sense to run the self-hosted runner on top of it.
@@ -14,21 +38,71 @@ actions-runner-controller uses [cert-manager](https://cert-manager.io/docs/insta
 
 - [Installing cert-manager on Kubernetes](https://cert-manager.io/docs/installation/kubernetes/)
 
-Install the custom resource and actions-runner-controller itself. This will create actions-runner-system namespace in your Kubernetes and deploy the required resources.
+Install the custom resource and actions-runner-controller with `kubectl` or `helm`. This will create actions-runner-system namespace in your Kubernetes and deploy the required resources.
+
+`kubectl`:
 
 ```
-kubectl apply -f https://github.com/summerwind/actions-runner-controller/releases/latest/download/actions-runner-controller.yaml
+# 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
+```
+
+`helm`:
+
+```
+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
 ```
 
 ### Github Enterprise support
 
-If you use either Github Enterprise Cloud or Server (and have recent enought version supporting Actions), you can use **actions-runner-controller**  with those, too. Authentication works same way as with public Github (repo and organization level).
+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.
+
 
 ```shell
 kubectl set env deploy controller-manager -c manager GITHUB_ENTERPRISE_URL=<GHEC/S URL> --namespace actions-runner-system
 ```
 
-[Enterprise level](https://docs.github.com/en/enterprise-server@2.22/actions/hosting-your-own-runners/adding-self-hosted-runners#adding-a-self-hosted-runner-to-an-enterprise) runners are not working yet as there's no API definition for those.
+#### Enterprise runners usage
+
+In order to use enterprise runners you must have Admin access to Github Enterprise and you should do Personal Access Token (PAT)
+with `enterprise:admin` access. Enterprise runners are not possible to run with Github APP or any other permission.
+
+When you use enterprise runners those will get access to Github Organisations. However, access to the repositories is **NOT**
+allowed by default. Each Github Organisation must allow Enterprise runner groups to be used in repositories.
+This is needed only one time and is permanent after that.
+
+Example:
+
+```yaml
+apiVersion: actions.summerwind.dev/v1alpha1
+kind: RunnerDeployment
+metadata:
+  name: ghe-runner-deployment
+spec:
+  replicas: 2
+  template:
+    spec:
+      enterprise: your-enterprise-name
+      dockerdWithinRunnerContainer: true
+      resources:
+        limits:
+          cpu: "4000m"
+          memory: "2Gi"
+        requests:
+          cpu: "200m"
+          memory: "200Mi"
+      volumeMounts:
+      - mountPath: /runner
+        name: runner
+      volumes:
+      - name: runner
+        emptyDir: {}
+
+```
 
 ## Setting up authentication with GitHub API
 
@@ -289,7 +363,119 @@ spec:
     scaleDownFactor: '0.7'
 ```
 
-## Runner with DinD
+#### Faster Autoscaling with GitHub Webhook
+
+> This feature is an ADVANCED feature which may require more work to set up.
+> 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).
+
+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`.
+
+More concretely, you can configure the targeted GitHub event types and the `N` in
+`scaleUpTriggers`:
+
+```yaml
+kind: HorizontalRunnerAutoscaler
+spec:
+  scaleTargetRef:
+    name: myrunners
+  scaleUpTrigggers:
+  - githubEvent:
+      checkRun:
+        types: ["created"]
+        status: "queued"
+    amount: 1
+    duration: "5m"
+```
+
+With the above example, the webhook server scales `myrunners` by `1` replica for 5 minutes on each `check_run` event
+with the type of `created` and the status of `queued` received. 
+
+The primary benefit of autoscaling on Webhook compared to the standard autoscaling is that this one allows you to
+immediately add "resource slack" for future GitHub Actions job runs.
+
+In contrast, the standard autoscaling requires you to wait next sync period to add
+insufficient runners. You can definitely shorten the sync period to make the standard autoscaling more responsive.
+But doing so eventually result in the controller not functional due to GitHub API rate limit.
+
+> You can learn the implementation details in #282
+
+To enable this feature, you firstly need to install the webhook server.
+
+Currently, only our Helm chart has the ability install it.
+
+```console
+$ helm --upgrade install actions-runner-controller/actions-runner-controller \
+  githubWebhookServer.enabled=true \
+  githubWebhookServer.ports[0].nodePort=33080
+```
+
+The above command will result in exposing the node port 33080 for Webhook events. Usually, you need to create an
+external loadbalancer targeted to the node port, and register the hostname or the IP address of the external loadbalancer
+to the GitHub Webhook.
+
+Once you were able to confirm that the Webhook server is ready and running from GitHub - this is usually verified by the
+GitHub sending PING events to the Webhook server - create or update your `HorizontalRunnerAutoscaler` resources
+by learning the following configuration examples.
+
+- [Example 1: Scale up on each `check_run` event](#example-1-scale-up-on-each-check_run-event)
+- [Example 2: Scale on each `pull_request` event against `develop` or `main` branches](#example-2-scale-on-each-pull_request-event-against-develop-or-main-branches)
+
+##### Example 1: Scale up on each `check_run` event
+
+> Note: This should work almost like https://github.com/philips-labs/terraform-aws-github-runner
+
+To scale up replicas of the runners for `example/myrepo` by 1 for 5 minutes on each `check_run`, you write manifests like the below:
+
+```yaml
+kind: RunnerDeployment
+metadata:
+   name: myrunners
+spec:
+  repository: example/myrepo
+---
+kind: HorizontalRunnerAutoscaler
+spec:
+  scaleTargetRef:
+    name: myrunners
+  scaleUpTrigggers:
+  - githubEvent:
+      checkRun:
+        types: ["created"]
+        status: "queued"
+    amount: 1
+    duration: "5m"
+```
+
+###### Example 2: Scale on each `pull_request` event against `develop` or `main` branches
+
+```yaml
+kind: RunnerDeployment:
+metadata:
+   name: myrunners
+spec:
+  repository: example/myrepo
+---
+kind: HorizontalRunnerAutoscaler
+spec:
+  scaleTargetRef:
+    name: myrunners
+  scaleUpTrigggers:
+  - githubEvent:
+      pullRequest:
+        types: ["synchronize"]
+        branches: ["main", "develop"]
+    amount: 1
+    duration: "5m"
+```
+
+See ["activity types"](https://docs.github.com/en/actions/reference/events-that-trigger-workflows#pull_request) for the list of valid values for `scaleUpTriggers[].githubEvent.pullRequest.types`.
+
+### Runner with DinD
 
 When using default runner, runner pod starts up 2 containers: runner and DinD (Docker-in-Docker). This might create issues if there's `LimitRange` set to namespace.
 
@@ -311,7 +497,7 @@ spec:
 
 This also helps with resources, as you don't need to give resources separately to docker and runner.
 
-## Additional tweaks
+### Additional tweaks
 
 You can pass details through the spec selector. Here's an eg. of what you may like to do:
 
@@ -343,6 +529,14 @@ 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
+          
       # 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.
@@ -370,7 +564,7 @@ spec:
       workDir: /home/runner/work
 ```
 
-## Runner labels
+### Runner labels
 
 To run a workflow job on a self-hosted runner, you can use the following syntax in your workflow:
 
@@ -407,7 +601,7 @@ jobs:
 
 Note that if you specify `self-hosted` in your workflow, then this will run your job on _any_ self-hosted runner, regardless of the labels that they have.
 
-## Runner Groups
+### Runner Groups
 
 Runner groups can be used to limit which repositories are able to use the GitHub Runner at an Organisation level. Runner groups have to be [created in GitHub first](https://docs.github.com/en/actions/hosting-your-own-runners/managing-access-to-self-hosted-runners-using-groups) before they can be referenced.
 
@@ -426,7 +620,7 @@ spec:
       group: NewGroup
 ```
 
-## Using EKS IAM role for service accounts
+### Using EKS IAM role for service accounts
 
 `actions-runner-controller` v0.15.0 or later has support for EKS IAM role for service accounts.
 
@@ -452,7 +646,7 @@ spec:
         fsGroup: 1447
 ```
 
-## Software installed in the runner image
+### Software installed in the runner image
 
 The GitHub hosted runners include a large amount of pre-installed software packages. For Ubuntu 18.04, this list can be found at <https://github.com/actions/virtual-environments/blob/master/images/linux/Ubuntu1804-README.md>
 
@@ -487,9 +681,9 @@ spec:
   image: YOUR_CUSTOM_DOCKER_IMAGE
 ```
 
-## Common Errors
+### Common Errors
 
-### invalid header field value
+#### invalid header field value
 
 ```json
 2020-11-12T22:17:30.693Z	ERROR	controller-runtime.controller	Reconciler error	{"controller": "runner", "request": "actions-runner-system/runner-deployment-dk7q8-dk5c9", "error": "failed to create registration token: Post \"https://api.github.com/orgs/$YOUR_ORG_HERE/actions/runners/registration-token\": net/http: invalid header field value \"Bearer $YOUR_TOKEN_HERE\\n\" for key Authorization"}

api/v1alpha1/horizontalrunnerautoscaler_types.go

@@ -41,6 +41,56 @@ type HorizontalRunnerAutoscalerSpec struct {
 	// Metrics is the collection of various metric targets to calculate desired number of runners
 	// +optional
 	Metrics []MetricSpec `json:"metrics,omitempty"`
+
+	// ScaleUpTriggers is an experimental feature to increase the desired replicas by 1
+	// on each webhook requested received by the webhookBasedAutoscaler.
+	//
+	// This feature requires you to also enable and deploy the webhookBasedAutoscaler onto your cluster.
+	//
+	// Note that the added runners remain until the next sync period at least,
+	// and they may or may not be used by GitHub Actions depending on the timing.
+	// They are intended to be used to gain "resource slack" immediately after you
+	// receive a webhook from GitHub, so that you can loosely expect MinReplicas runners to be always available.
+	ScaleUpTriggers []ScaleUpTrigger `json:"scaleUpTriggers,omitempty"`
+
+	CapacityReservations []CapacityReservation `json:"capacityReservations,omitempty" patchStrategy:"merge" patchMergeKey:"name"`
+}
+
+type ScaleUpTrigger struct {
+	GitHubEvent *GitHubEventScaleUpTriggerSpec `json:"githubEvent,omitempty"`
+	Amount      int                            `json:"amount,omitempty"`
+	Duration    metav1.Duration                `json:"duration,omitempty"`
+}
+
+type GitHubEventScaleUpTriggerSpec struct {
+	CheckRun    *CheckRunSpec    `json:"checkRun,omitempty"`
+	PullRequest *PullRequestSpec `json:"pullRequest,omitempty"`
+	Push        *PushSpec        `json:"push,omitempty"`
+}
+
+// https://docs.github.com/en/actions/reference/events-that-trigger-workflows#check_run
+type CheckRunSpec struct {
+	Types  []string `json:"types,omitempty"`
+	Status string   `json:"status,omitempty"`
+}
+
+// https://docs.github.com/en/actions/reference/events-that-trigger-workflows#pull_request
+type PullRequestSpec struct {
+	Types    []string `json:"types,omitempty"`
+	Branches []string `json:"branches,omitempty"`
+}
+
+// PushSpec is the condition for triggering scale-up on push event
+// Also see https://docs.github.com/en/actions/reference/events-that-trigger-workflows#push
+type PushSpec struct {
+}
+
+// CapacityReservation specifies the number of replicas temporarily added
+// to the scale target until ExpirationTime.
+type CapacityReservation struct {
+	Name           string      `json:"name,omitempty"`
+	ExpirationTime metav1.Time `json:"expirationTime,omitempty"`
+	Replicas       int         `json:"replicas,omitempty"`
 }
 
 type ScaleTargetRef struct {
@@ -76,6 +126,16 @@ type MetricSpec struct {
 	// to determine how many pods should be removed.
 	// +optional
 	ScaleDownFactor string `json:"scaleDownFactor,omitempty"`
+
+	// ScaleUpAdjustment is the number of runners added on scale-up.
+	// You can only specify either ScaleUpFactor or ScaleUpAdjustment.
+	// +optional
+	ScaleUpAdjustment int `json:"scaleUpAdjustment,omitempty"`
+
+	// ScaleDownAdjustment is the number of runners removed on scale-down.
+	// You can only specify either ScaleDownFactor or ScaleDownAdjustment.
+	// +optional
+	ScaleDownAdjustment int `json:"scaleDownAdjustment,omitempty"`
 }
 
 type HorizontalRunnerAutoscalerStatus struct {
@@ -91,6 +151,17 @@ type HorizontalRunnerAutoscalerStatus struct {
 
 	// +optional
 	LastSuccessfulScaleOutTime *metav1.Time `json:"lastSuccessfulScaleOutTime,omitempty"`
+
+	// +optional
+	CacheEntries []CacheEntry `json:"cacheEntries,omitempty"`
+}
+
+const CacheEntryKeyDesiredReplicas = "desiredReplicas"
+
+type CacheEntry struct {
+	Key            string      `json:"key,omitempty"`
+	Value          int         `json:"value,omitempty"`
+	ExpirationTime metav1.Time `json:"expirationTime,omitempty"`
 }
 
 // +kubebuilder:object:root=true

api/v1alpha1/runner_types.go

@@ -25,6 +25,10 @@ import (
 
 // RunnerSpec defines the desired state of Runner
 type RunnerSpec struct {
+	// +optional
+	// +kubebuilder:validation:Pattern=`^[^/]+$`
+	Enterprise string `json:"enterprise,omitempty"`
+
 	// +optional
 	// +kubebuilder:validation:Pattern=`^[^/]+$`
 	Organization string `json:"organization,omitempty"`
@@ -92,12 +96,22 @@ type RunnerSpec struct {
 
 // ValidateRepository validates repository field.
 func (rs *RunnerSpec) ValidateRepository() error {
-	// Organization and repository are both exclusive.
-	if len(rs.Organization) == 0 && len(rs.Repository) == 0 {
-		return errors.New("Spec needs organization or repository")
+	// Enterprise, Organization and repository are both exclusive.
+	foundCount := 0
+	if len(rs.Organization) > 0 {
+		foundCount += 1
 	}
-	if len(rs.Organization) > 0 && len(rs.Repository) > 0 {
-		return errors.New("Spec cannot have both organization and repository")
+	if len(rs.Repository) > 0 {
+		foundCount += 1
+	}
+	if len(rs.Enterprise) > 0 {
+		foundCount += 1
+	}
+	if foundCount == 0 {
+		return errors.New("Spec needs enterprise, organization or repository")
+	}
+	if foundCount > 1 {
+		return errors.New("Spec cannot have many fields defined enterprise, organization and repository")
 	}
 
 	return nil
@@ -113,6 +127,7 @@ type RunnerStatus struct {
 
 // RunnerStatusRegistration contains runner registration status
 type RunnerStatusRegistration struct {
+	Enterprise   string      `json:"enterprise,omitempty"`
 	Organization string      `json:"organization,omitempty"`
 	Repository   string      `json:"repository,omitempty"`
 	Labels       []string    `json:"labels,omitempty"`
@@ -122,6 +137,7 @@ type RunnerStatusRegistration struct {
 
 // +kubebuilder:object:root=true
 // +kubebuilder:subresource:status
+// +kubebuilder:printcolumn:JSONPath=".spec.enterprise",name=Enterprise,type=string
 // +kubebuilder:printcolumn:JSONPath=".spec.organization",name=Organization,type=string
 // +kubebuilder:printcolumn:JSONPath=".spec.repository",name=Repository,type=string
 // +kubebuilder:printcolumn:JSONPath=".spec.labels",name=Labels,type=string

api/v1alpha1/zz_generated.deepcopy.go

@@ -25,6 +25,88 @@ import (
 	"k8s.io/apimachinery/pkg/runtime"
 )
 
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *CacheEntry) DeepCopyInto(out *CacheEntry) {
+	*out = *in
+	in.ExpirationTime.DeepCopyInto(&out.ExpirationTime)
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new CacheEntry.
+func (in *CacheEntry) DeepCopy() *CacheEntry {
+	if in == nil {
+		return nil
+	}
+	out := new(CacheEntry)
+	in.DeepCopyInto(out)
+	return out
+}
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *CapacityReservation) DeepCopyInto(out *CapacityReservation) {
+	*out = *in
+	in.ExpirationTime.DeepCopyInto(&out.ExpirationTime)
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new CapacityReservation.
+func (in *CapacityReservation) DeepCopy() *CapacityReservation {
+	if in == nil {
+		return nil
+	}
+	out := new(CapacityReservation)
+	in.DeepCopyInto(out)
+	return out
+}
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *CheckRunSpec) DeepCopyInto(out *CheckRunSpec) {
+	*out = *in
+	if in.Types != nil {
+		in, out := &in.Types, &out.Types
+		*out = make([]string, len(*in))
+		copy(*out, *in)
+	}
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new CheckRunSpec.
+func (in *CheckRunSpec) DeepCopy() *CheckRunSpec {
+	if in == nil {
+		return nil
+	}
+	out := new(CheckRunSpec)
+	in.DeepCopyInto(out)
+	return out
+}
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *GitHubEventScaleUpTriggerSpec) DeepCopyInto(out *GitHubEventScaleUpTriggerSpec) {
+	*out = *in
+	if in.CheckRun != nil {
+		in, out := &in.CheckRun, &out.CheckRun
+		*out = new(CheckRunSpec)
+		(*in).DeepCopyInto(*out)
+	}
+	if in.PullRequest != nil {
+		in, out := &in.PullRequest, &out.PullRequest
+		*out = new(PullRequestSpec)
+		(*in).DeepCopyInto(*out)
+	}
+	if in.Push != nil {
+		in, out := &in.Push, &out.Push
+		*out = new(PushSpec)
+		**out = **in
+	}
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new GitHubEventScaleUpTriggerSpec.
+func (in *GitHubEventScaleUpTriggerSpec) DeepCopy() *GitHubEventScaleUpTriggerSpec {
+	if in == nil {
+		return nil
+	}
+	out := new(GitHubEventScaleUpTriggerSpec)
+	in.DeepCopyInto(out)
+	return out
+}
+
 // DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
 func (in *HorizontalRunnerAutoscaler) DeepCopyInto(out *HorizontalRunnerAutoscaler) {
 	*out = *in
@@ -110,6 +192,20 @@ func (in *HorizontalRunnerAutoscalerSpec) DeepCopyInto(out *HorizontalRunnerAuto
 			(*in)[i].DeepCopyInto(&(*out)[i])
 		}
 	}
+	if in.ScaleUpTriggers != nil {
+		in, out := &in.ScaleUpTriggers, &out.ScaleUpTriggers
+		*out = make([]ScaleUpTrigger, len(*in))
+		for i := range *in {
+			(*in)[i].DeepCopyInto(&(*out)[i])
+		}
+	}
+	if in.CapacityReservations != nil {
+		in, out := &in.CapacityReservations, &out.CapacityReservations
+		*out = make([]CapacityReservation, len(*in))
+		for i := range *in {
+			(*in)[i].DeepCopyInto(&(*out)[i])
+		}
+	}
 }
 
 // DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new HorizontalRunnerAutoscalerSpec.
@@ -134,6 +230,13 @@ func (in *HorizontalRunnerAutoscalerStatus) DeepCopyInto(out *HorizontalRunnerAu
 		in, out := &in.LastSuccessfulScaleOutTime, &out.LastSuccessfulScaleOutTime
 		*out = (*in).DeepCopy()
 	}
+	if in.CacheEntries != nil {
+		in, out := &in.CacheEntries, &out.CacheEntries
+		*out = make([]CacheEntry, len(*in))
+		for i := range *in {
+			(*in)[i].DeepCopyInto(&(*out)[i])
+		}
+	}
 }
 
 // DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new HorizontalRunnerAutoscalerStatus.
@@ -166,6 +269,46 @@ func (in *MetricSpec) DeepCopy() *MetricSpec {
 	return out
 }
 
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *PullRequestSpec) DeepCopyInto(out *PullRequestSpec) {
+	*out = *in
+	if in.Types != nil {
+		in, out := &in.Types, &out.Types
+		*out = make([]string, len(*in))
+		copy(*out, *in)
+	}
+	if in.Branches != nil {
+		in, out := &in.Branches, &out.Branches
+		*out = make([]string, len(*in))
+		copy(*out, *in)
+	}
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new PullRequestSpec.
+func (in *PullRequestSpec) DeepCopy() *PullRequestSpec {
+	if in == nil {
+		return nil
+	}
+	out := new(PullRequestSpec)
+	in.DeepCopyInto(out)
+	return out
+}
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *PushSpec) DeepCopyInto(out *PushSpec) {
+	*out = *in
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new PushSpec.
+func (in *PushSpec) DeepCopy() *PushSpec {
+	if in == nil {
+		return nil
+	}
+	out := new(PushSpec)
+	in.DeepCopyInto(out)
+	return out
+}
+
 // DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
 func (in *Runner) DeepCopyInto(out *Runner) {
 	*out = *in
@@ -615,3 +758,24 @@ func (in *ScaleTargetRef) DeepCopy() *ScaleTargetRef {
 	in.DeepCopyInto(out)
 	return out
 }
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *ScaleUpTrigger) DeepCopyInto(out *ScaleUpTrigger) {
+	*out = *in
+	if in.GitHubEvent != nil {
+		in, out := &in.GitHubEvent, &out.GitHubEvent
+		*out = new(GitHubEventScaleUpTriggerSpec)
+		(*in).DeepCopyInto(*out)
+	}
+	out.Duration = in.Duration
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new ScaleUpTrigger.
+func (in *ScaleUpTrigger) DeepCopy() *ScaleUpTrigger {
+	if in == nil {
+		return nil
+	}
+	out := new(ScaleUpTrigger)
+	in.DeepCopyInto(out)
+	return out
+}

charts/.ci/ct-config.yaml

@@ -0,0 +1,4 @@
+# This file defines the config for "ct" (chart tester) used by the helm linting GitHub workflow
+lint-conf: charts/.ci/lint-config.yaml
+chart-repos:
+  - jetstack=https://charts.jetstack.io

charts/.ci/lint-config.yaml

@@ -0,0 +1,6 @@
+rules:
+  # One blank line is OK
+  empty-lines: 
+    max-start: 1
+    max-end: 1
+    max: 1

charts/.ci/scripts/local-ct-lint.sh

@@ -0,0 +1,3 @@
+#!/bin/bash
+
+docker run --rm -it -w /repo -v $(pwd):/repo quay.io/helmpack/chart-testing ct lint --all --config charts/.ci/ct-config.yaml

charts/.ci/scripts/local-kube-score.sh

@@ -0,0 +1,15 @@
+#!/bin/bash
+
+
+for chart in `ls charts`;
+do
+helm template --values charts/$chart/ci/ci-values.yaml charts/$chart | kube-score score - \
+    --ignore-test pod-networkpolicy \
+    --ignore-test deployment-has-poddisruptionbudget \
+    --ignore-test deployment-has-host-podantiaffinity \
+    --ignore-test pod-probes \
+    --ignore-test container-image-tag \
+    --enable-optional-test container-security-context-privileged \
+    --enable-optional-test container-security-context-readonlyrootfilesystem \
+    --ignore-test container-security-context
+done

charts/actions-runner-controller/Chart.yaml

@@ -15,9 +15,17 @@ 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: 0.1.0
+version: 0.5.0
 
-# This is the version number of the application being deployed. This version number should be
-# incremented each time you make changes to the application. Versions are not expected to
-# follow Semantic Versioning. They should reflect the version the application is using.
-appVersion: 0.11.2
+home: https://github.com/summerwind/actions-runner-controller
+
+sources:
+    - https://github.com/summerwind/actions-runner-controller
+
+maintainers:
+    - name: summerwind
+      email: contact@summerwind.jp
+      url: https://github.com/summerwind
+    - name: funkypenguin
+      email: davidy@funkypenguin.co.nz
+      url: https://www.funkypenguin.co.nz

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

@@ -0,0 +1,27 @@
+# This file sets some opinionated values for kube-score to use
+# when parsing the chart
+image:
+  pullPolicy: Always
+
+podSecurityContext:
+  fsGroup: 2000
+
+securityContext: 
+  capabilities:
+    drop:
+    - ALL
+  readOnlyRootFilesystem: true
+  runAsNonRoot: true
+  runAsUser: 2000
+
+resources: 
+  limits:
+    cpu: 100m
+    memory: 128Mi
+  requests:
+    cpu: 100m
+    memory: 128Mi  
+
+# 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

@@ -48,6 +48,20 @@ spec:
           description: HorizontalRunnerAutoscalerSpec defines the desired state of
             HorizontalRunnerAutoscaler
           properties:
+            capacityReservations:
+              items:
+                description: CapacityReservation specifies the number of replicas
+                  temporarily added to the scale target until ExpirationTime.
+                properties:
+                  expirationTime:
+                    format: date-time
+                    type: string
+                  name:
+                    type: string
+                  replicas:
+                    type: integer
+                type: object
+              type: array
             maxReplicas:
               description: MinReplicas is the maximum number of replicas the deployment
                 is allowed to scale
@@ -64,6 +78,11 @@ spec:
                     items:
                       type: string
                     type: array
+                  scaleDownAdjustment:
+                    description: ScaleDownAdjustment is the number of runners removed
+                      on scale-down. You can only specify either ScaleDownFactor or
+                      ScaleDownAdjustment.
+                    type: integer
                   scaleDownFactor:
                     description: ScaleDownFactor is the multiplicative factor applied
                       to the current number of runners used to determine how many
@@ -73,6 +92,10 @@ spec:
                     description: ScaleDownThreshold is the percentage of busy runners
                       less than which will trigger the hpa to scale the runners down.
                     type: string
+                  scaleUpAdjustment:
+                    description: ScaleUpAdjustment is the number of runners added
+                      on scale-up. You can only specify either ScaleUpFactor or ScaleUpAdjustment.
+                    type: integer
                   scaleUpFactor:
                     description: ScaleUpFactor is the multiplicative factor applied
                       to the current number of runners used to determine how many
@@ -104,9 +127,68 @@ spec:
                 name:
                   type: string
               type: object
+            scaleUpTriggers:
+              description: "ScaleUpTriggers is an experimental feature to increase
+                the desired replicas by 1 on each webhook requested received by the
+                webhookBasedAutoscaler. \n This feature requires you to also enable
+                and deploy the webhookBasedAutoscaler onto your cluster. \n Note that
+                the added runners remain until the next sync period at least, and
+                they may or may not be used by GitHub Actions depending on the timing.
+                They are intended to be used to gain \"resource slack\" immediately
+                after you receive a webhook from GitHub, so that you can loosely expect
+                MinReplicas runners to be always available."
+              items:
+                properties:
+                  amount:
+                    type: integer
+                  duration:
+                    type: string
+                  githubEvent:
+                    properties:
+                      checkRun:
+                        description: https://docs.github.com/en/actions/reference/events-that-trigger-workflows#check_run
+                        properties:
+                          status:
+                            type: string
+                          types:
+                            items:
+                              type: string
+                            type: array
+                        type: object
+                      pullRequest:
+                        description: https://docs.github.com/en/actions/reference/events-that-trigger-workflows#pull_request
+                        properties:
+                          branches:
+                            items:
+                              type: string
+                            type: array
+                          types:
+                            items:
+                              type: string
+                            type: array
+                        type: object
+                      push:
+                        description: PushSpec is the condition for triggering scale-up
+                          on push event Also see https://docs.github.com/en/actions/reference/events-that-trigger-workflows#push
+                        type: object
+                    type: object
+                type: object
+              type: array
           type: object
         status:
           properties:
+            cacheEntries:
+              items:
+                properties:
+                  expirationTime:
+                    format: date-time
+                    type: string
+                  key:
+                    type: string
+                  value:
+                    type: integer
+                type: object
+              type: array
             desiredReplicas:
               description: DesiredReplicas is the total number of desired, non-terminated
                 and latest pods to be set for the primary RunnerSet This doesn't include

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

@@ -426,6 +426,9 @@ spec:
                       type: object
                     dockerdWithinRunnerContainer:
                       type: boolean
+                    enterprise:
+                      pattern: ^[^/]+$
+                      type: string
                     env:
                       items:
                         description: EnvVar represents an environment variable present in a Container.

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

@@ -426,6 +426,9 @@ spec:
                       type: object
                     dockerdWithinRunnerContainer:
                       type: boolean
+                    enterprise:
+                      pattern: ^[^/]+$
+                      type: string
                     env:
                       items:
                         description: EnvVar represents an environment variable present in a Container.

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

@@ -7,6 +7,9 @@ metadata:
   name: runners.actions.summerwind.dev
 spec:
   additionalPrinterColumns:
+    - JSONPath: .spec.enterprise
+      name: Enterprise
+      type: string
     - JSONPath: .spec.organization
       name: Organization
       type: string
@@ -419,6 +422,9 @@ spec:
               type: object
             dockerdWithinRunnerContainer:
               type: boolean
+            enterprise:
+              pattern: ^[^/]+$
+              type: string
             env:
               items:
                 description: EnvVar represents an environment variable present in a Container.
@@ -1541,6 +1547,8 @@ spec:
             registration:
               description: RunnerStatusRegistration contains runner registration status
               properties:
+                enterprise:
+                  type: string
                 expiresAt:
                   format: date-time
                   type: string

charts/actions-runner-controller/templates/_github_webhook_server_helpers.tpl

@@ -0,0 +1,52 @@
+{{/*
+Expand the name of the chart.
+*/}}
+{{- define "actions-runner-controller-github-webhook-server.name" -}}
+{{- default .Chart.Name .Values.githubWebhookServer.nameOverride | trunc 63 | trimSuffix "-" }}
+{{- end }}
+
+{{- define "actions-runner-controller-github-webhook-server.instance" -}}
+{{- printf "%s-%s" .Release.Name "github-webhook-server" }}
+{{- end }}
+
+{{/*
+Create a default fully qualified app name.
+We truncate at 63 chars because some Kubernetes name fields are limited to this (by the DNS naming spec).
+If release name contains chart name it will be used as a full name.
+*/}}
+{{- define "actions-runner-controller-github-webhook-server.fullname" -}}
+{{- if .Values.githubWebhookServer.fullnameOverride }}
+{{- .Values.githubWebhookServer.fullnameOverride | trunc 63 | trimSuffix "-" }}
+{{- else }}
+{{- $name := default .Chart.Name .Values.githubWebhookServer.nameOverride }}
+{{- $instance := include "actions-runner-controller-github-webhook-server.instance" . }}
+{{- if contains $name $instance }}
+{{- $instance | trunc 63 | trimSuffix "-" }}
+{{- else }}
+{{- printf "%s-%s-%s" .Release.Name $name "github-webhook-server" | trunc 63 | trimSuffix "-" }}
+{{- end }}
+{{- end }}
+{{- end }}
+
+{{/*
+Selector labels
+*/}}
+{{- define "actions-runner-controller-github-webhook-server.selectorLabels" -}}
+app.kubernetes.io/name: {{ include "actions-runner-controller-github-webhook-server.name" . }}
+app.kubernetes.io/instance: {{ include "actions-runner-controller-github-webhook-server.instance" . }}
+{{- end }}
+
+{{/*
+Create the name of the service account to use
+*/}}
+{{- define "actions-runner-controller-github-webhook-server.serviceAccountName" -}}
+{{- if .Values.githubWebhookServer.serviceAccount.create }}
+{{- default (include "actions-runner-controller-github-webhook-server.fullname" .) .Values.githubWebhookServer.serviceAccount.name }}
+{{- else }}
+{{- default "default" .Values.githubWebhookServer.serviceAccount.name }}
+{{- end }}
+{{- end }}
+
+{{- define "actions-runner-controller-github-webhook-server.roleName" -}}
+{{- include "actions-runner-controller-github-webhook-server.fullname" . }}
+{{- end }}

charts/actions-runner-controller/templates/_helpers.tpl

@@ -89,7 +89,7 @@ Create the name of the service account to use
 {{- end }}
 
 {{- define "actions-runner-controller.authProxyServiceName" -}}
-{{- include "actions-runner-controller.fullname" . }}-controller-manager-metrics-service
+{{- include "actions-runner-controller.fullname" . }}-metrics-service
 {{- end }}
 
 {{- define "actions-runner-controller.selfsignedIssuerName" -}}

charts/actions-runner-controller/templates/ci-secret.yaml

@@ -0,0 +1,10 @@
+# This template only exists to facilitate CI testing of the chart, since
+# a secret is expected to be found in the namespace by the controller manager
+{{ if .Values.createDummySecret -}}
+apiVersion: v1
+data:
+  github_token: dGVzdA==
+kind: Secret
+metadata:
+  name: controller-manager
+{{- end }}

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

@@ -57,6 +57,10 @@ spec:
               optional: true
         - name: GITHUB_APP_PRIVATE_KEY
           value: /etc/actions-runner-controller/github_app_private_key
+        {{- range $key, $val := .Values.env }}
+        - name: {{ $key }}
+          value: {{ $val | quote }}
+        {{- end }}
         image: "{{ .Values.image.repository }}:{{ .Values.image.tag | default (cat "v" .Chart.AppVersion | replace " " "") }}"
         name: manager
         imagePullPolicy: {{ .Values.image.pullPolicy }}
@@ -66,10 +70,14 @@ spec:
           protocol: TCP
         resources:
           {{- toYaml .Values.resources | nindent 12 }}
+        securityContext:
+          {{- toYaml .Values.securityContext | nindent 12 }}          
         volumeMounts:
         - mountPath: "/etc/actions-runner-controller"
           name: controller-manager
           readOnly: true
+        - mountPath: /tmp
+          name: tmp         
         - mountPath: /tmp/k8s-webhook-server/serving-certs
           name: cert
           readOnly: true
@@ -78,11 +86,16 @@ spec:
         - "--upstream=http://127.0.0.1:8080/"
         - "--logtostderr=true"
         - "--v=10"
-        image: gcr.io/kubebuilder/kube-rbac-proxy:v0.4.1
+        image: "{{ .Values.kube_rbac_proxy.image.repository }}:{{ .Values.kube_rbac_proxy.image.tag }}"
         name: kube-rbac-proxy
+        imagePullPolicy: {{ .Values.image.pullPolicy }}
         ports:
         - containerPort: 8443
           name: https
+        resources:
+          {{- toYaml .Values.resources | nindent 12 }}   
+        securityContext:
+          {{- toYaml .Values.securityContext | nindent 12 }}     
       terminationGracePeriodSeconds: 10
       volumes:
       - name: controller-manager
@@ -92,6 +105,8 @@ spec:
         secret:
           defaultMode: 420
           secretName: webhook-server-cert
+      - name: tmp
+        emptyDir: {}
       {{- with .Values.nodeSelector }}
       nodeSelector:
         {{- toYaml . | nindent 8 }}

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

@@ -0,0 +1,93 @@
+{{- if .Values.githubWebhookServer.enabled }}
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: {{ include "actions-runner-controller-github-webhook-server.fullname" . }}
+  namespace: {{ .Release.Namespace }}
+  labels:
+    {{- include "actions-runner-controller.labels" . | nindent 4 }}
+spec:
+  selector:
+    matchLabels:
+      {{- include "actions-runner-controller-github-webhook-server.selectorLabels" . | nindent 6 }}
+  template:
+    metadata:
+      {{- with .Values.githubWebhookServer.podAnnotations }}
+      annotations:
+        {{- toYaml . | nindent 8 }}
+      {{- end }}
+      labels:
+        {{- include "actions-runner-controller-github-webhook-server.selectorLabels" . | nindent 8 }}
+    spec:
+      {{- with .Values.githubWebhookServer.imagePullSecrets }}
+      imagePullSecrets:
+        {{- toYaml . | nindent 8 }}
+      {{- end }}
+      serviceAccountName: {{ include "actions-runner-controller-github-webhook-server.serviceAccountName" . }}
+      securityContext:
+        {{- toYaml .Values.githubWebhookServer.podSecurityContext | nindent 8 }}
+      {{- with .Values.githubWebhookServer.priorityClassName }}
+      priorityClassName: "{{ . }}"
+      {{- end }}
+      containers:
+      - args:
+        - "--metrics-addr=127.0.0.1:8080"
+        - "--enable-leader-election"
+        - "--sync-period={{ .Values.githubWebhookServer.syncPeriod }}"
+        command:
+        - "/github-webhook-server"
+        env:
+        - name: GITHUB_WEBHOOK_SECRET_TOKEN
+          valueFrom:
+            secretKeyRef:
+              key: github_webhook_secret_token
+              name: github-webhook-server
+              optional: true
+        {{- range $key, $val := .Values.githubWebhookServer.env }}
+        - name: {{ $key }}
+          value: {{ $val | quote }}
+        {{- end }}
+        image: "{{ .Values.githubWebhookServer.image.repository }}:{{ .Values.githubWebhookServer.image.tag | default (cat "v" .Chart.AppVersion | replace " " "") }}"
+        name: github-webhook-server
+        imagePullPolicy: {{ .Values.image.pullPolicy }}
+        ports:
+        - containerPort: 8000
+          name: github-webhook-server
+          protocol: TCP
+        resources:
+          {{- toYaml .Values.githubWebhookServer.resources | nindent 12 }}
+        securityContext:
+          {{- toYaml .Values.githubWebhookServer.securityContext | nindent 12 }}
+      - args:
+        - "--secure-listen-address=0.0.0.0:8443"
+        - "--upstream=http://127.0.0.1:8080/"
+        - "--logtostderr=true"
+        - "--v=10"
+        image: "{{ .Values.kube_rbac_proxy.image.repository }}:{{ .Values.kube_rbac_proxy.image.tag }}"
+        name: kube-rbac-proxy
+        imagePullPolicy: {{ .Values.image.pullPolicy }}
+        ports:
+        - containerPort: 8443
+          name: https
+        resources:
+          {{- toYaml .Values.resources | nindent 12 }}   
+        securityContext:
+          {{- toYaml .Values.securityContext | nindent 12 }}     
+      terminationGracePeriodSeconds: 10
+      volumes:
+      - name: github-webhook-server
+        secret:
+          secretName: github-webhook-server
+      {{- with .Values.githubWebhookServer.nodeSelector }}
+      nodeSelector:
+        {{- toYaml . | nindent 8 }}
+      {{- end }}
+      {{- with .Values.githubWebhookServer.affinity }}
+      affinity:
+        {{- toYaml . | nindent 8 }}
+      {{- end }}
+      {{- with .Values.githubWebhookServer.tolerations }}
+      tolerations:
+        {{- toYaml . | nindent 8 }}
+      {{- end }}
+{{- end }}

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

@@ -0,0 +1,70 @@
+{{- if .Values.githubWebhookServer.enabled }}
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRole
+metadata:
+  creationTimestamp: null
+  name: {{ include "actions-runner-controller-github-webhook-server.roleName" . }}
+rules:
+- apiGroups:
+  - actions.summerwind.dev
+  resources:
+  - horizontalrunnerautoscalers
+  verbs:
+  - get
+  - list
+  - patch
+  - update
+  - watch
+- apiGroups:
+  - actions.summerwind.dev
+  resources:
+  - horizontalrunnerautoscalers/finalizers
+  verbs:
+  - create
+  - delete
+  - get
+  - list
+  - patch
+  - update
+  - watch
+- apiGroups:
+  - actions.summerwind.dev
+  resources:
+  - horizontalrunnerautoscalers/status
+  verbs:
+  - get
+  - patch
+  - update
+- apiGroups:
+  - actions.summerwind.dev
+  resources:
+  - runnerdeployments
+  verbs:
+  - create
+  - delete
+  - get
+  - list
+  - patch
+  - update
+  - watch
+- apiGroups:
+  - actions.summerwind.dev
+  resources:
+  - runnerdeployments/finalizers
+  verbs:
+  - create
+  - delete
+  - get
+  - list
+  - patch
+  - update
+  - watch
+- apiGroups:
+  - actions.summerwind.dev
+  resources:
+  - runnerdeployments/status
+  verbs:
+  - get
+  - patch
+  - update
+{{- end }}

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

@@ -0,0 +1,16 @@
+{{- if .Values.githubWebhookServer.enabled }}
+{{- if .Values.githubWebhookServer.secret.enabled }}
+apiVersion: v1
+kind: Secret
+metadata:
+  name: github-webhook-server
+  namespace: {{ .Release.Namespace }}
+  labels:
+    {{- include "actions-runner-controller.labels" . | nindent 4 }}
+type: Opaque
+data:
+{{- range $k, $v := .Values.githubWebhookServer.secret }}
+  {{ $k }}: {{ $v | toString | b64enc }}
+{{- end }} 
+{{- end }}
+{{- end }}

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

@@ -0,0 +1,17 @@
+{{- if .Values.githubWebhookServer.enabled }}
+apiVersion: v1
+kind: Service
+metadata:
+  name: {{ include "actions-runner-controller-github-webhook-server.fullname" . }}
+  namespace: {{ .Release.Namespace }}
+  labels:
+    {{- include "actions-runner-controller.labels" . | nindent 4 }}
+spec:
+  type: {{ .Values.githubWebhookServer.service.type }}
+  ports:
+    {{ range $_, $port := .Values.githubWebhookServer.service.ports -}}
+    - {{ $port | toYaml | nindent 6 }}
+    {{- end }}
+  selector:
+    {{- include "actions-runner-controller-github-webhook-server.selectorLabels" . | nindent 4 }}
+{{- end }}

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

@@ -0,0 +1,15 @@
+{{- if .Values.githubWebhookServer.enabled -}}
+{{- if .Values.githubWebhookServer.serviceAccount.create -}}
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: {{ include "actions-runner-controller-github-webhook-server.serviceAccountName" . }}
+  namespace: {{ .Release.Namespace }}
+  labels:
+    {{- include "actions-runner-controller.labels" . | nindent 4 }}
+  {{- with .Values.githubWebhookServer.serviceAccount.annotations }}
+  annotations:
+    {{- toYaml . | nindent 4 }}
+  {{- end }}
+{{- end }}
+{{- end }}

charts/actions-runner-controller/values.yaml

@@ -26,6 +26,11 @@ image:
   dindSidecarRepositoryAndTag: "docker:dind"
   pullPolicy: IfNotPresent
 
+kube_rbac_proxy:
+  image:
+    repository: quay.io/brancz/kube-rbac-proxy
+    tag: v0.8.0
+
 imagePullSecrets: []
 nameOverride: ""
 fullnameOverride: ""
@@ -98,3 +103,51 @@ affinity: {}
 # ref: https://kubernetes.io/docs/concepts/configuration/pod-priority-preemption/
 # PriorityClass: system-cluster-critical
 priorityClassName: ""
+
+env: {}
+  # http_proxy: "proxy.com:8080"
+  # https_proxy: "proxy.com:8080"
+  # no_proxy: ""
+
+githubWebhookServer:
+  enabled: false
+  labels: {}
+  replicaCount: 1
+  syncPeriod: 10m
+  secret:
+    enabled: false
+    ### GitHub Webhook Configuration
+    #github_webhook_secret_token: ""
+  image:
+    repository: summerwind/actions-runner-controller
+    # Overrides the manager image tag whose default is the chart appVersion if the tag key is commented out
+    tag: "latest"
+    pullPolicy: IfNotPresent
+  imagePullSecrets: []
+  nameOverride: ""
+  fullnameOverride: ""
+  serviceAccount:
+    # Specifies whether a service account should be created
+    create: true
+    # Annotations to add to the service account
+    annotations: {}
+    # The name of the service account to use.
+    # If not set and create is true, a name is generated using the fullname template
+    name: ""
+  podAnnotations: {}
+  podSecurityContext: {}
+  # fsGroup: 2000
+  securityContext: {}
+  resources: {}
+  nodeSelector: {}
+  tolerations: []
+  affinity: {}
+  priorityClassName: ""
+  service:
+    type: NodePort
+    ports:
+    - port: 80
+      targetPort: 8000
+      protocol: TCP
+      name: http
+      #nodePort: someFixedPortForUseWithTerraformCdkCfnEtc

cmd/githubwebhookserver/main.go

@@ -0,0 +1,169 @@
+/*
+Copyright 2021 The actions-runner-controller authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package main
+
+import (
+	"context"
+	"errors"
+	"flag"
+	"net/http"
+	"os"
+	"sync"
+	"time"
+
+	actionsv1alpha1 "github.com/summerwind/actions-runner-controller/api/v1alpha1"
+	"github.com/summerwind/actions-runner-controller/controllers"
+	"k8s.io/apimachinery/pkg/runtime"
+	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
+	_ "k8s.io/client-go/plugin/pkg/client/auth/exec"
+	_ "k8s.io/client-go/plugin/pkg/client/auth/gcp"
+	_ "k8s.io/client-go/plugin/pkg/client/auth/oidc"
+	ctrl "sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/log/zap"
+	// +kubebuilder:scaffold:imports
+)
+
+var (
+	scheme   = runtime.NewScheme()
+	setupLog = ctrl.Log.WithName("setup")
+)
+
+func init() {
+	_ = clientgoscheme.AddToScheme(scheme)
+
+	_ = actionsv1alpha1.AddToScheme(scheme)
+	// +kubebuilder:scaffold:scheme
+}
+
+func main() {
+	var (
+		err error
+
+		webhookAddr string
+		metricsAddr string
+
+		// The secret token of the GitHub Webhook. See https://docs.github.com/en/developers/webhooks-and-events/securing-your-webhooks
+		webhookSecretToken string
+
+		watchNamespace string
+
+		enableLeaderElection bool
+		syncPeriod           time.Duration
+	)
+
+	webhookSecretToken = os.Getenv("GITHUB_WEBHOOK_SECRET_TOKEN")
+
+	flag.StringVar(&webhookAddr, "webhook-addr", ":8000", "The address the metric endpoint binds to.")
+	flag.StringVar(&metricsAddr, "metrics-addr", ":8080", "The address the metric endpoint binds to.")
+	flag.StringVar(&watchNamespace, "watch-namespace", "", "The namespace to watch for HorizontalRunnerAutoscaler's to scale on Webhook. Set to empty for letting it watch for all namespaces.")
+	flag.BoolVar(&enableLeaderElection, "enable-leader-election", false,
+		"Enable leader election for controller manager. Enabling this will ensure there is only one active controller manager.")
+	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.Parse()
+
+	if webhookSecretToken == "" {
+		setupLog.Info("-webhook-secret-token is missing or empty. Create one following https://docs.github.com/en/developers/webhooks-and-events/securing-your-webhooks")
+	}
+
+	if watchNamespace == "" {
+		setupLog.Info("-watch-namespace is empty. HorizontalRunnerAutoscalers in all the namespaces are watched, cached, and considered as scale targets.")
+	} else {
+		setupLog.Info("-watch-namespace is %q. Only HorizontalRunnerAutoscalers in %q are watched, cached, and considered as scale targets.")
+	}
+
+	logger := zap.New(func(o *zap.Options) {
+		o.Development = true
+	})
+
+	ctrl.SetLogger(logger)
+
+	mgr, err := ctrl.NewManager(ctrl.GetConfigOrDie(), ctrl.Options{
+		Scheme:             scheme,
+		SyncPeriod:         &syncPeriod,
+		LeaderElection:     enableLeaderElection,
+		Namespace:          watchNamespace,
+		MetricsBindAddress: metricsAddr,
+		Port:               9443,
+	})
+	if err != nil {
+		setupLog.Error(err, "unable to start manager")
+		os.Exit(1)
+	}
+
+	hraGitHubWebhook := &controllers.HorizontalRunnerAutoscalerGitHubWebhook{
+		Client:         mgr.GetClient(),
+		Log:            ctrl.Log.WithName("controllers").WithName("Runner"),
+		Recorder:       nil,
+		Scheme:         mgr.GetScheme(),
+		SecretKeyBytes: []byte(webhookSecretToken),
+		WatchNamespace: watchNamespace,
+	}
+
+	if err = hraGitHubWebhook.SetupWithManager(mgr); err != nil {
+		setupLog.Error(err, "unable to create controller", "controller", "Runner")
+		os.Exit(1)
+	}
+
+	var wg sync.WaitGroup
+
+	ctx, cancel := context.WithCancel(context.Background())
+
+	wg.Add(1)
+	go func() {
+		defer cancel()
+		defer wg.Done()
+
+		setupLog.Info("starting webhook server")
+		if err := mgr.Start(ctx.Done()); err != nil {
+			setupLog.Error(err, "problem running manager")
+			os.Exit(1)
+		}
+	}()
+
+	mux := http.NewServeMux()
+	mux.HandleFunc("/", hraGitHubWebhook.Handle)
+
+	srv := http.Server{
+		Addr:    webhookAddr,
+		Handler: mux,
+	}
+
+	wg.Add(1)
+	go func() {
+		defer cancel()
+		defer wg.Done()
+
+		go func() {
+			<-ctx.Done()
+
+			srv.Shutdown(context.Background())
+		}()
+
+		if err := srv.ListenAndServe(); err != nil {
+			if !errors.Is(err, http.ErrServerClosed) {
+				setupLog.Error(err, "problem running http server")
+			}
+		}
+	}()
+
+	go func() {
+		<-ctrl.SetupSignalHandler()
+		cancel()
+	}()
+
+	wg.Wait()
+}

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

@@ -48,6 +48,20 @@ spec:
           description: HorizontalRunnerAutoscalerSpec defines the desired state of
             HorizontalRunnerAutoscaler
           properties:
+            capacityReservations:
+              items:
+                description: CapacityReservation specifies the number of replicas
+                  temporarily added to the scale target until ExpirationTime.
+                properties:
+                  expirationTime:
+                    format: date-time
+                    type: string
+                  name:
+                    type: string
+                  replicas:
+                    type: integer
+                type: object
+              type: array
             maxReplicas:
               description: MinReplicas is the maximum number of replicas the deployment
                 is allowed to scale
@@ -64,6 +78,11 @@ spec:
                     items:
                       type: string
                     type: array
+                  scaleDownAdjustment:
+                    description: ScaleDownAdjustment is the number of runners removed
+                      on scale-down. You can only specify either ScaleDownFactor or
+                      ScaleDownAdjustment.
+                    type: integer
                   scaleDownFactor:
                     description: ScaleDownFactor is the multiplicative factor applied
                       to the current number of runners used to determine how many
@@ -73,6 +92,10 @@ spec:
                     description: ScaleDownThreshold is the percentage of busy runners
                       less than which will trigger the hpa to scale the runners down.
                     type: string
+                  scaleUpAdjustment:
+                    description: ScaleUpAdjustment is the number of runners added
+                      on scale-up. You can only specify either ScaleUpFactor or ScaleUpAdjustment.
+                    type: integer
                   scaleUpFactor:
                     description: ScaleUpFactor is the multiplicative factor applied
                       to the current number of runners used to determine how many
@@ -104,9 +127,68 @@ spec:
                 name:
                   type: string
               type: object
+            scaleUpTriggers:
+              description: "ScaleUpTriggers is an experimental feature to increase
+                the desired replicas by 1 on each webhook requested received by the
+                webhookBasedAutoscaler. \n This feature requires you to also enable
+                and deploy the webhookBasedAutoscaler onto your cluster. \n Note that
+                the added runners remain until the next sync period at least, and
+                they may or may not be used by GitHub Actions depending on the timing.
+                They are intended to be used to gain \"resource slack\" immediately
+                after you receive a webhook from GitHub, so that you can loosely expect
+                MinReplicas runners to be always available."
+              items:
+                properties:
+                  amount:
+                    type: integer
+                  duration:
+                    type: string
+                  githubEvent:
+                    properties:
+                      checkRun:
+                        description: https://docs.github.com/en/actions/reference/events-that-trigger-workflows#check_run
+                        properties:
+                          status:
+                            type: string
+                          types:
+                            items:
+                              type: string
+                            type: array
+                        type: object
+                      pullRequest:
+                        description: https://docs.github.com/en/actions/reference/events-that-trigger-workflows#pull_request
+                        properties:
+                          branches:
+                            items:
+                              type: string
+                            type: array
+                          types:
+                            items:
+                              type: string
+                            type: array
+                        type: object
+                      push:
+                        description: PushSpec is the condition for triggering scale-up
+                          on push event Also see https://docs.github.com/en/actions/reference/events-that-trigger-workflows#push
+                        type: object
+                    type: object
+                type: object
+              type: array
           type: object
         status:
           properties:
+            cacheEntries:
+              items:
+                properties:
+                  expirationTime:
+                    format: date-time
+                    type: string
+                  key:
+                    type: string
+                  value:
+                    type: integer
+                type: object
+              type: array
             desiredReplicas:
               description: DesiredReplicas is the total number of desired, non-terminated
                 and latest pods to be set for the primary RunnerSet This doesn't include

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

@@ -426,6 +426,9 @@ spec:
                       type: object
                     dockerdWithinRunnerContainer:
                       type: boolean
+                    enterprise:
+                      pattern: ^[^/]+$
+                      type: string
                     env:
                       items:
                         description: EnvVar represents an environment variable present in a Container.

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

@@ -426,6 +426,9 @@ spec:
                       type: object
                     dockerdWithinRunnerContainer:
                       type: boolean
+                    enterprise:
+                      pattern: ^[^/]+$
+                      type: string
                     env:
                       items:
                         description: EnvVar represents an environment variable present in a Container.

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

@@ -7,6 +7,9 @@ metadata:
   name: runners.actions.summerwind.dev
 spec:
   additionalPrinterColumns:
+    - JSONPath: .spec.enterprise
+      name: Enterprise
+      type: string
     - JSONPath: .spec.organization
       name: Organization
       type: string
@@ -419,6 +422,9 @@ spec:
               type: object
             dockerdWithinRunnerContainer:
               type: boolean
+            enterprise:
+              pattern: ^[^/]+$
+              type: string
             env:
               items:
                 description: EnvVar represents an environment variable present in a Container.
@@ -1541,6 +1547,8 @@ spec:
             registration:
               description: RunnerStatusRegistration contains runner registration status
               properties:
+                enterprise:
+                  type: string
                 expiresAt:
                   format: date-time
                   type: string

config/default/manager_auth_proxy_patch.yaml

@@ -10,7 +10,7 @@ spec:
     spec:
       containers:
       - name: kube-rbac-proxy
-        image: gcr.io/kubebuilder/kube-rbac-proxy:v0.4.1
+        image: quay.io/brancz/kube-rbac-proxy:v0.8.0
         args:
         - "--secure-listen-address=0.0.0.0:8443"
         - "--upstream=http://127.0.0.1:8080/"

controllers/autoscaling.go

@@ -7,6 +7,7 @@ import (
 	"math"
 	"strconv"
 	"strings"
+	"time"
 
 	"github.com/summerwind/actions-runner-controller/api/v1alpha1"
 	"sigs.k8s.io/controller-runtime/pkg/client"
@@ -19,6 +20,47 @@ const (
 	defaultScaleDownFactor    = 0.7
 )
 
+func getValueAvailableAt(now time.Time, from, to *time.Time, reservedValue int) *int {
+	if to != nil && now.After(*to) {
+		return nil
+	}
+
+	if from != nil && now.Before(*from) {
+		return nil
+	}
+
+	return &reservedValue
+}
+
+func (r *HorizontalRunnerAutoscalerReconciler) getDesiredReplicasFromCache(hra v1alpha1.HorizontalRunnerAutoscaler) *int {
+	var entry *v1alpha1.CacheEntry
+
+	for i := range hra.Status.CacheEntries {
+		ent := hra.Status.CacheEntries[i]
+
+		if ent.Key != v1alpha1.CacheEntryKeyDesiredReplicas {
+			continue
+		}
+
+		if !time.Now().Before(ent.ExpirationTime.Time) {
+			continue
+		}
+
+		entry = &ent
+
+		break
+	}
+
+	if entry != nil {
+		v := getValueAvailableAt(time.Now(), nil, &entry.ExpirationTime.Time, entry.Value)
+		if v != nil {
+			return v
+		}
+	}
+
+	return nil
+}
+
 func (r *HorizontalRunnerAutoscalerReconciler) determineDesiredReplicas(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)
@@ -96,12 +138,12 @@ func (r *HorizontalRunnerAutoscalerReconciler) calculateReplicasByQueuedAndInPro
 
 	for _, repo := range repos {
 		user, repoName := repo[0], repo[1]
-		list, _, err := r.GitHubClient.Actions.ListRepositoryWorkflowRuns(context.TODO(), user, repoName, nil)
+		workflowRuns, err := r.GitHubClient.ListRepositoryWorkflowRuns(context.TODO(), user, repoName)
 		if err != nil {
 			return nil, err
 		}
 
-		for _, run := range list.WorkflowRuns {
+		for _, run := range workflowRuns {
 			total++
 
 			// In May 2020, there are only 3 statuses.
@@ -147,6 +189,9 @@ func (r *HorizontalRunnerAutoscalerReconciler) calculateReplicasByQueuedAndInPro
 		"workflow_runs_in_progress", inProgress,
 		"workflow_runs_queued", queued,
 		"workflow_runs_unknown", unknown,
+		"namespace", hra.Namespace,
+		"runner_deployment", rd.Name,
+		"horizontal_runner_autoscaler", hra.Name,
 	)
 
 	return &replicas, nil
@@ -154,7 +199,6 @@ func (r *HorizontalRunnerAutoscalerReconciler) calculateReplicasByQueuedAndInPro
 
 func (r *HorizontalRunnerAutoscalerReconciler) calculateReplicasByPercentageRunnersBusy(rd v1alpha1.RunnerDeployment, hra v1alpha1.HorizontalRunnerAutoscaler) (*int, error) {
 	ctx := context.Background()
-	orgName := rd.Spec.Template.Spec.Organization
 	minReplicas := *hra.Spec.MinReplicas
 	maxReplicas := *hra.Spec.MaxReplicas
 	metrics := hra.Spec.Metrics[0]
@@ -178,14 +222,34 @@ func (r *HorizontalRunnerAutoscalerReconciler) calculateReplicasByPercentageRunn
 
 		scaleDownThreshold = sdt
 	}
-	if metrics.ScaleUpFactor != "" {
+
+	scaleUpAdjustment := metrics.ScaleUpAdjustment
+	if scaleUpAdjustment != 0 {
+		if metrics.ScaleUpAdjustment < 0 {
+			return nil, errors.New("validating autoscaling metrics: spec.autoscaling.metrics[].scaleUpAdjustment cannot be lower than 0")
+		}
+
+		if metrics.ScaleUpFactor != "" {
+			return nil, errors.New("validating autoscaling metrics: spec.autoscaling.metrics[]: scaleUpAdjustment and scaleUpFactor cannot be specified together")
+		}
+	} else if metrics.ScaleUpFactor != "" {
 		suf, err := strconv.ParseFloat(metrics.ScaleUpFactor, 64)
 		if err != nil {
 			return nil, errors.New("validating autoscaling metrics: spec.autoscaling.metrics[].scaleUpFactor cannot be parsed into a float64")
 		}
 		scaleUpFactor = suf
 	}
-	if metrics.ScaleDownFactor != "" {
+
+	scaleDownAdjustment := metrics.ScaleDownAdjustment
+	if scaleDownAdjustment != 0 {
+		if metrics.ScaleDownAdjustment < 0 {
+			return nil, errors.New("validating autoscaling metrics: spec.autoscaling.metrics[].scaleDownAdjustment cannot be lower than 0")
+		}
+
+		if metrics.ScaleDownFactor != "" {
+			return nil, errors.New("validating autoscaling metrics: spec.autoscaling.metrics[]: scaleDownAdjustment and scaleDownFactor cannot be specified together")
+		}
+	} else if metrics.ScaleDownFactor != "" {
 		sdf, err := strconv.ParseFloat(metrics.ScaleDownFactor, 64)
 		if err != nil {
 			return nil, errors.New("validating autoscaling metrics: spec.autoscaling.metrics[].scaleDownFactor cannot be parsed into a float64")
@@ -203,8 +267,18 @@ func (r *HorizontalRunnerAutoscalerReconciler) calculateReplicasByPercentageRunn
 		runnerMap[items.Name] = struct{}{}
 	}
 
+	var (
+		enterprise   = rd.Spec.Template.Spec.Enterprise
+		organization = rd.Spec.Template.Spec.Organization
+		repository   = rd.Spec.Template.Spec.Repository
+	)
+
 	// ListRunners will return all runners managed by GitHub - not restricted to ns
-	runners, err := r.GitHubClient.ListRunners(ctx, orgName, "")
+	runners, err := r.GitHubClient.ListRunners(
+		ctx,
+		enterprise,
+		organization,
+		repository)
 	if err != nil {
 		return nil, err
 	}
@@ -219,9 +293,17 @@ func (r *HorizontalRunnerAutoscalerReconciler) calculateReplicasByPercentageRunn
 	var desiredReplicas int
 	fractionBusy := float64(numRunnersBusy) / float64(numRunners)
 	if fractionBusy >= scaleUpThreshold {
-		desiredReplicas = int(math.Ceil(float64(numRunners) * scaleUpFactor))
+		if scaleUpAdjustment > 0 {
+			desiredReplicas = numRunners + scaleUpAdjustment
+		} else {
+			desiredReplicas = int(math.Ceil(float64(numRunners) * scaleUpFactor))
+		}
 	} else if fractionBusy < scaleDownThreshold {
-		desiredReplicas = int(float64(numRunners) * scaleDownFactor)
+		if scaleDownAdjustment > 0 {
+			desiredReplicas = numRunners - scaleDownAdjustment
+		} else {
+			desiredReplicas = int(float64(numRunners) * scaleDownFactor)
+		}
 	} else {
 		desiredReplicas = *rd.Spec.Replicas
 	}
@@ -240,6 +322,12 @@ func (r *HorizontalRunnerAutoscalerReconciler) calculateReplicasByPercentageRunn
 		"current_replicas", rd.Spec.Replicas,
 		"num_runners", numRunners,
 		"num_runners_busy", numRunnersBusy,
+		"namespace", hra.Namespace,
+		"runner_deployment", rd.Name,
+		"horizontal_runner_autoscaler", hra.Name,
+		"enterprise", enterprise,
+		"organization", organization,
+		"repository", repository,
 	)
 
 	rd.Status.Replicas = &desiredReplicas

controllers/autoscaling_test.go

@@ -157,7 +157,11 @@ func TestDetermineDesiredReplicas_RepositoryRunner(t *testing.T) {
 		_ = v1alpha1.AddToScheme(scheme)
 
 		t.Run(fmt.Sprintf("case %d", i), func(t *testing.T) {
-			server := fake.NewServer(fake.WithListRepositoryWorkflowRunsResponse(200, tc.workflowRuns), fake.WithListWorkflowJobsResponse(200, tc.workflowJobs))
+			server := fake.NewServer(
+				fake.WithListRepositoryWorkflowRunsResponse(200, tc.workflowRuns),
+				fake.WithListWorkflowJobsResponse(200, tc.workflowJobs),
+				fake.WithListRunnersResponse(200, fake.RunnersListBody),
+			)
 			defer server.Close()
 			client := newGithubClient(server)
 
@@ -368,7 +372,11 @@ func TestDetermineDesiredReplicas_OrganizationalRunner(t *testing.T) {
 		_ = v1alpha1.AddToScheme(scheme)
 
 		t.Run(fmt.Sprintf("case %d", i), func(t *testing.T) {
-			server := fake.NewServer(fake.WithListRepositoryWorkflowRunsResponse(200, tc.workflowRuns), fake.WithListWorkflowJobsResponse(200, tc.workflowJobs))
+			server := fake.NewServer(
+				fake.WithListRepositoryWorkflowRunsResponse(200, tc.workflowRuns),
+				fake.WithListWorkflowJobsResponse(200, tc.workflowJobs),
+				fake.WithListRunnersResponse(200, fake.RunnersListBody),
+			)
 			defer server.Close()
 			client := newGithubClient(server)
 

controllers/horizontal_runner_autoscaler_webhook.go

@@ -0,0 +1,375 @@
+/*
+Copyright 2020 The actions-runner-controller authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package controllers
+
+import (
+	"context"
+	"fmt"
+	"io/ioutil"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/types"
+	"net/http"
+	"sigs.k8s.io/controller-runtime/pkg/reconcile"
+	"time"
+
+	"github.com/go-logr/logr"
+	gogithub "github.com/google/go-github/v33/github"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/client-go/tools/record"
+	ctrl "sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+
+	"github.com/summerwind/actions-runner-controller/api/v1alpha1"
+)
+
+const (
+	scaleTargetKey = "scaleTarget"
+)
+
+// HorizontalRunnerAutoscalerGitHubWebhook autoscales a HorizontalRunnerAutoscaler and the RunnerDeployment on each
+// GitHub Webhook received
+type HorizontalRunnerAutoscalerGitHubWebhook struct {
+	client.Client
+	Log      logr.Logger
+	Recorder record.EventRecorder
+	Scheme   *runtime.Scheme
+
+	// SecretKeyBytes is the byte representation of the Webhook secret token
+	// the administrator is generated and specified in GitHub Web UI.
+	SecretKeyBytes []byte
+
+	// WatchNamespace 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
+}
+
+func (autoscaler *HorizontalRunnerAutoscalerGitHubWebhook) Reconcile(request reconcile.Request) (reconcile.Result, error) {
+	return ctrl.Result{}, nil
+}
+
+// +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
+// +kubebuilder:rbac:groups=actions.summerwind.dev,resources=horizontalrunnerautoscalers/status,verbs=get;update;patch
+// +kubebuilder:rbac:groups=core,resources=events,verbs=create;patch
+
+func (autoscaler *HorizontalRunnerAutoscalerGitHubWebhook) Handle(w http.ResponseWriter, r *http.Request) {
+	var (
+		ok bool
+
+		err error
+	)
+
+	defer func() {
+		if !ok {
+			w.WriteHeader(http.StatusInternalServerError)
+
+			if err != nil {
+				msg := err.Error()
+				if written, err := w.Write([]byte(msg)); err != nil {
+					autoscaler.Log.Error(err, "failed writing http error response", "msg", msg, "written", written)
+				}
+			}
+		}
+	}()
+
+	defer func() {
+		if r.Body != nil {
+			r.Body.Close()
+		}
+	}()
+
+	var payload []byte
+
+	if len(autoscaler.SecretKeyBytes) > 0 {
+		payload, err = gogithub.ValidatePayload(r, autoscaler.SecretKeyBytes)
+		if err != nil {
+			autoscaler.Log.Error(err, "error validating request body")
+
+			return
+		}
+	} else {
+		payload, err = ioutil.ReadAll(r.Body)
+		if err != nil {
+			autoscaler.Log.Error(err, "error reading request body")
+
+			return
+		}
+	}
+
+	webhookType := gogithub.WebHookType(r)
+	event, err := gogithub.ParseWebHook(webhookType, payload)
+	if err != nil {
+		var s string
+		if payload != nil {
+			s = string(payload)
+		}
+
+		autoscaler.Log.Error(err, "could not parse webhook", "webhookType", webhookType, "payload", s)
+
+		return
+	}
+
+	var target *ScaleTarget
+
+	autoscaler.Log.Info("processing webhook event", "eventType", webhookType)
+
+	switch e := event.(type) {
+	case *gogithub.PushEvent:
+		target, err = autoscaler.getScaleUpTarget(
+			context.TODO(),
+			*e.Repo.Name,
+			*e.Repo.Organization,
+			autoscaler.MatchPushEvent(e),
+		)
+	case *gogithub.PullRequestEvent:
+		target, err = autoscaler.getScaleUpTarget(
+			context.TODO(),
+			*e.Repo.Name,
+			*e.Repo.Organization.Name,
+			autoscaler.MatchPullRequestEvent(e),
+		)
+	case *gogithub.CheckRunEvent:
+		target, err = autoscaler.getScaleUpTarget(
+			context.TODO(),
+			*e.Repo.Name,
+			*e.Org.Name,
+			autoscaler.MatchCheckRunEvent(e),
+		)
+	case *gogithub.PingEvent:
+		ok = true
+
+		w.WriteHeader(http.StatusOK)
+
+		msg := "pong"
+
+		if written, err := w.Write([]byte(msg)); err != nil {
+			autoscaler.Log.Error(err, "failed writing http response", "msg", msg, "written", written)
+		}
+
+		autoscaler.Log.Info("received ping event")
+
+		return
+	default:
+		autoscaler.Log.Info("unknown event type", "eventType", webhookType)
+
+		return
+	}
+
+	if err != nil {
+		autoscaler.Log.Error(err, "handling check_run event")
+
+		return
+	}
+
+	if target == nil {
+		msg := "no horizontalrunnerautoscaler to scale for this github event"
+
+		autoscaler.Log.Info(msg, "eventType", webhookType)
+
+		ok = true
+
+		w.WriteHeader(http.StatusOK)
+
+		if written, err := w.Write([]byte(msg)); err != nil {
+			autoscaler.Log.Error(err, "failed writing http response", "msg", msg, "written", written)
+		}
+
+		return
+	}
+
+	if err := autoscaler.tryScaleUp(context.TODO(), target); err != nil {
+		autoscaler.Log.Error(err, "could not scale up")
+
+		return
+	}
+
+	ok = true
+
+	w.WriteHeader(http.StatusOK)
+
+	msg := fmt.Sprintf("scaled %s by 1", target.Name)
+
+	autoscaler.Log.Info(msg)
+
+	if written, err := w.Write([]byte(msg)); err != nil {
+		autoscaler.Log.Error(err, "failed writing http response", "msg", msg, "written", written)
+	}
+}
+
+func (autoscaler *HorizontalRunnerAutoscalerGitHubWebhook) findHRAsByKey(ctx context.Context, value string) ([]v1alpha1.HorizontalRunnerAutoscaler, error) {
+	ns := autoscaler.WatchNamespace
+
+	var defaultListOpts []client.ListOption
+
+	if ns != "" {
+		defaultListOpts = append(defaultListOpts, client.InNamespace(ns))
+	}
+
+	var hras []v1alpha1.HorizontalRunnerAutoscaler
+
+	if value != "" {
+		opts := append([]client.ListOption{}, defaultListOpts...)
+		opts = append(opts, client.MatchingFields{scaleTargetKey: value})
+
+		var hraList v1alpha1.HorizontalRunnerAutoscalerList
+
+		if err := autoscaler.List(ctx, &hraList, opts...); err != nil {
+			return nil, err
+		}
+
+		for _, d := range hraList.Items {
+			hras = append(hras, d)
+		}
+	}
+
+	return hras, nil
+}
+
+func matchTriggerConditionAgainstEvent(types []string, eventAction *string) bool {
+	if len(types) == 0 {
+		return true
+	}
+
+	if eventAction == nil {
+		return false
+	}
+
+	for _, tpe := range types {
+		if tpe == *eventAction {
+			return true
+		}
+	}
+
+	return false
+}
+
+type ScaleTarget struct {
+	v1alpha1.HorizontalRunnerAutoscaler
+	v1alpha1.ScaleUpTrigger
+}
+
+func (autoscaler *HorizontalRunnerAutoscalerGitHubWebhook) searchScaleTargets(hras []v1alpha1.HorizontalRunnerAutoscaler, f func(v1alpha1.ScaleUpTrigger) bool) []ScaleTarget {
+	var matched []ScaleTarget
+
+	for _, hra := range hras {
+		if !hra.ObjectMeta.DeletionTimestamp.IsZero() {
+			continue
+		}
+
+		for _, scaleUpTrigger := range hra.Spec.ScaleUpTriggers {
+			if !f(scaleUpTrigger) {
+				continue
+			}
+
+			matched = append(matched, ScaleTarget{
+				HorizontalRunnerAutoscaler: hra,
+				ScaleUpTrigger:             scaleUpTrigger,
+			})
+		}
+	}
+
+	return matched
+}
+
+func (autoscaler *HorizontalRunnerAutoscalerGitHubWebhook) getScaleTarget(ctx context.Context, name string, f func(v1alpha1.ScaleUpTrigger) bool) (*ScaleTarget, error) {
+	hras, err := autoscaler.findHRAsByKey(ctx, name)
+	if err != nil {
+		return nil, err
+	}
+
+	targets := autoscaler.searchScaleTargets(hras, f)
+
+	if len(targets) != 1 {
+		return nil, nil
+	}
+
+	return &targets[0], nil
+}
+
+func (autoscaler *HorizontalRunnerAutoscalerGitHubWebhook) getScaleUpTarget(ctx context.Context, repoNameFromWebhook, orgNameFromWebhook string, f func(v1alpha1.ScaleUpTrigger) bool) (*ScaleTarget, error) {
+	if target, err := autoscaler.getScaleTarget(ctx, repoNameFromWebhook, f); err != nil {
+		return nil, err
+	} else if target != nil {
+		autoscaler.Log.Info("scale up target is repository-wide runners", "repository", repoNameFromWebhook)
+		return target, nil
+	}
+
+	if target, err := autoscaler.getScaleTarget(ctx, orgNameFromWebhook, f); err != nil {
+		return nil, err
+	} else if target != nil {
+		autoscaler.Log.Info("scale up target is organizational runners", "repository", orgNameFromWebhook)
+		return target, nil
+	}
+
+	return nil, nil
+}
+
+func (autoscaler *HorizontalRunnerAutoscalerGitHubWebhook) tryScaleUp(ctx context.Context, target *ScaleTarget) error {
+	if target == nil {
+		return nil
+	}
+
+	log := autoscaler.Log.WithValues("horizontalrunnerautoscaler", target.HorizontalRunnerAutoscaler.Name)
+
+	copy := target.HorizontalRunnerAutoscaler.DeepCopy()
+
+	amount := 1
+
+	if target.ScaleUpTrigger.Amount > 0 {
+		amount = target.ScaleUpTrigger.Amount
+	}
+
+	copy.Spec.CapacityReservations = append(copy.Spec.CapacityReservations, v1alpha1.CapacityReservation{
+		ExpirationTime: metav1.Time{Time: time.Now().Add(target.ScaleUpTrigger.Duration.Duration)},
+		Replicas:       amount,
+	})
+
+	if err := autoscaler.Client.Update(ctx, copy); err != nil {
+		log.Error(err, "Failed to update horizontalrunnerautoscaler resource")
+
+		return err
+	}
+
+	return nil
+}
+
+func (autoscaler *HorizontalRunnerAutoscalerGitHubWebhook) SetupWithManager(mgr ctrl.Manager) error {
+	autoscaler.Recorder = mgr.GetEventRecorderFor("webhookbasedautoscaler")
+
+	if err := mgr.GetFieldIndexer().IndexField(&v1alpha1.HorizontalRunnerAutoscaler{}, scaleTargetKey, func(rawObj runtime.Object) []string {
+		hra := rawObj.(*v1alpha1.HorizontalRunnerAutoscaler)
+
+		if hra.Spec.ScaleTargetRef.Name == "" {
+			return nil
+		}
+
+		var rd v1alpha1.RunnerDeployment
+
+		if err := autoscaler.Client.Get(context.Background(), types.NamespacedName{Namespace: hra.Namespace, Name: hra.Spec.ScaleTargetRef.Name}, &rd); err != nil {
+			return nil
+		}
+
+		return []string{rd.Spec.Template.Spec.Repository, rd.Spec.Template.Spec.Organization}
+	}); err != nil {
+		return err
+	}
+
+	return ctrl.NewControllerManagedBy(mgr).
+		For(&v1alpha1.HorizontalRunnerAutoscaler{}).
+		Complete(autoscaler)
+}

controllers/horizontal_runner_autoscaler_webhook_on_check_run.go

@@ -0,0 +1,32 @@
+package controllers
+
+import (
+	"github.com/google/go-github/v33/github"
+	"github.com/summerwind/actions-runner-controller/api/v1alpha1"
+)
+
+func (autoscaler *HorizontalRunnerAutoscalerGitHubWebhook) MatchCheckRunEvent(event *github.CheckRunEvent) func(scaleUpTrigger v1alpha1.ScaleUpTrigger) bool {
+	return func(scaleUpTrigger v1alpha1.ScaleUpTrigger) bool {
+		g := scaleUpTrigger.GitHubEvent
+
+		if g == nil {
+			return false
+		}
+
+		cr := g.CheckRun
+
+		if cr == nil {
+			return false
+		}
+
+		if !matchTriggerConditionAgainstEvent(cr.Types, event.Action) {
+			return false
+		}
+
+		if cr.Status != "" && (event.CheckRun == nil || event.CheckRun.Status == nil || *event.CheckRun.Status != cr.Status) {
+			return false
+		}
+
+		return true
+	}
+}

controllers/horizontal_runner_autoscaler_webhook_on_pull_request.go

@@ -0,0 +1,32 @@
+package controllers
+
+import (
+	"github.com/google/go-github/v33/github"
+	"github.com/summerwind/actions-runner-controller/api/v1alpha1"
+)
+
+func (autoscaler *HorizontalRunnerAutoscalerGitHubWebhook) MatchPullRequestEvent(event *github.PullRequestEvent) func(scaleUpTrigger v1alpha1.ScaleUpTrigger) bool {
+	return func(scaleUpTrigger v1alpha1.ScaleUpTrigger) bool {
+		g := scaleUpTrigger.GitHubEvent
+
+		if g == nil {
+			return false
+		}
+
+		pr := g.PullRequest
+
+		if pr == nil {
+			return false
+		}
+
+		if !matchTriggerConditionAgainstEvent(pr.Types, event.Action) {
+			return false
+		}
+
+		if !matchTriggerConditionAgainstEvent(pr.Branches, event.PullRequest.Base.Ref) {
+			return false
+		}
+
+		return true
+	}
+}

controllers/horizontal_runner_autoscaler_webhook_on_push.go

@@ -0,0 +1,24 @@
+package controllers
+
+import (
+	"github.com/google/go-github/v33/github"
+	"github.com/summerwind/actions-runner-controller/api/v1alpha1"
+)
+
+func (autoscaler *HorizontalRunnerAutoscalerGitHubWebhook) MatchPushEvent(event *github.PushEvent) func(scaleUpTrigger v1alpha1.ScaleUpTrigger) bool {
+	return func(scaleUpTrigger v1alpha1.ScaleUpTrigger) bool {
+		g := scaleUpTrigger.GitHubEvent
+
+		if g == nil {
+			return false
+		}
+
+		push := g.Push
+
+		if push == nil {
+			return false
+		}
+
+		return true
+	}
+}

controllers/horizontal_runner_autoscaler_webhook_test.go

@@ -0,0 +1,245 @@
+package controllers
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"github.com/go-logr/logr"
+	"github.com/google/go-github/v33/github"
+	actionsv1alpha1 "github.com/summerwind/actions-runner-controller/api/v1alpha1"
+	"io"
+	"io/ioutil"
+	"k8s.io/apimachinery/pkg/runtime"
+	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"sigs.k8s.io/controller-runtime/pkg/client/fake"
+	"testing"
+)
+
+var (
+	sc = runtime.NewScheme()
+)
+
+func init() {
+	_ = clientgoscheme.AddToScheme(sc)
+	_ = actionsv1alpha1.AddToScheme(sc)
+}
+
+func TestWebhookCheckRun(t *testing.T) {
+	testServer(t,
+		"check_run",
+		&github.CheckRunEvent{
+			CheckRun: &github.CheckRun{
+				Status: github.String("queued"),
+			},
+			Repo: &github.Repository{
+				Name: github.String("myorg/myrepo"),
+			},
+			Org: &github.Organization{
+				Name: github.String("myorg"),
+			},
+			Action: github.String("created"),
+		},
+		200,
+		"no horizontalrunnerautoscaler to scale for this github event",
+	)
+}
+
+func TestWebhookPullRequest(t *testing.T) {
+	testServer(t,
+		"pull_request",
+		&github.PullRequestEvent{
+			PullRequest: &github.PullRequest{
+				Base: &github.PullRequestBranch{
+					Ref: github.String("main"),
+				},
+			},
+			Repo: &github.Repository{
+				Name: github.String("myorg/myrepo"),
+				Organization: &github.Organization{
+					Name: github.String("myorg"),
+				},
+			},
+			Action: github.String("created"),
+		},
+		200,
+		"no horizontalrunnerautoscaler to scale for this github event",
+	)
+}
+
+func TestWebhookPush(t *testing.T) {
+	testServer(t,
+		"push",
+		&github.PushEvent{
+			Repo: &github.PushEventRepository{
+				Name:         github.String("myrepo"),
+				Organization: github.String("myorg"),
+			},
+		},
+		200,
+		"no horizontalrunnerautoscaler to scale for this github event",
+	)
+}
+
+func TestWebhookPing(t *testing.T) {
+	testServer(t,
+		"ping",
+		&github.PingEvent{
+			Zen: github.String("zen"),
+		},
+		200,
+		"pong",
+	)
+}
+
+func installTestLogger(webhook *HorizontalRunnerAutoscalerGitHubWebhook) *bytes.Buffer {
+	logs := &bytes.Buffer{}
+
+	log := testLogger{
+		name:   "testlog",
+		writer: logs,
+	}
+
+	webhook.Log = &log
+
+	return logs
+}
+
+func testServer(t *testing.T, eventType string, event interface{}, wantCode int, wantBody string) {
+	t.Helper()
+
+	hraWebhook := &HorizontalRunnerAutoscalerGitHubWebhook{}
+
+	var initObjs []runtime.Object
+
+	client := fake.NewFakeClientWithScheme(sc, initObjs...)
+
+	logs := installTestLogger(hraWebhook)
+
+	defer func() {
+		if t.Failed() {
+			t.Logf("diagnostics: %s", logs.String())
+		}
+	}()
+
+	hraWebhook.Client = client
+
+	mux := http.NewServeMux()
+	mux.HandleFunc("/", hraWebhook.Handle)
+
+	server := httptest.NewServer(mux)
+	defer server.Close()
+
+	resp, err := sendWebhook(server, eventType, event)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	defer func() {
+		if resp != nil {
+			resp.Body.Close()
+		}
+	}()
+
+	if resp.StatusCode != wantCode {
+		t.Error("status:", resp.StatusCode)
+	}
+
+	respBody, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if string(respBody) != wantBody {
+		t.Fatal("body:", string(respBody))
+	}
+}
+
+func sendWebhook(server *httptest.Server, eventType string, event interface{}) (*http.Response, error) {
+	jsonBuf := &bytes.Buffer{}
+	enc := json.NewEncoder(jsonBuf)
+	enc.SetIndent("  ", "")
+	err := enc.Encode(event)
+	if err != nil {
+		return nil, fmt.Errorf("[bug in test] encoding event to json: %+v", err)
+	}
+
+	reqBody := jsonBuf.Bytes()
+
+	u, err := url.Parse(server.URL)
+	if err != nil {
+		return nil, fmt.Errorf("parsing server url: %v", err)
+	}
+
+	req := &http.Request{
+		Method: http.MethodPost,
+		URL:    u,
+		Header: map[string][]string{
+			"X-GitHub-Event": {eventType},
+			"Content-Type":   {"application/json"},
+		},
+		Body: ioutil.NopCloser(bytes.NewBuffer(reqBody)),
+	}
+
+	return http.DefaultClient.Do(req)
+}
+
+// testLogger is a sample logr.Logger that logs in-memory.
+// It's only for testing log outputs.
+type testLogger struct {
+	name      string
+	keyValues map[string]interface{}
+
+	writer io.Writer
+}
+
+var _ logr.Logger = &testLogger{}
+
+func (l *testLogger) Info(msg string, kvs ...interface{}) {
+	fmt.Fprintf(l.writer, "%s] %s\t", l.name, msg)
+	for k, v := range l.keyValues {
+		fmt.Fprintf(l.writer, "%s=%+v ", k, v)
+	}
+	for i := 0; i < len(kvs); i += 2 {
+		fmt.Fprintf(l.writer, "%s=%+v ", kvs[i], kvs[i+1])
+	}
+	fmt.Fprintf(l.writer, "\n")
+}
+
+func (_ *testLogger) Enabled() bool {
+	return true
+}
+
+func (l *testLogger) Error(err error, msg string, kvs ...interface{}) {
+	kvs = append(kvs, "error", err)
+	l.Info(msg, kvs...)
+}
+
+func (l *testLogger) V(_ int) logr.InfoLogger {
+	return l
+}
+
+func (l *testLogger) WithName(name string) logr.Logger {
+	return &testLogger{
+		name:      l.name + "." + name,
+		keyValues: l.keyValues,
+		writer:    l.writer,
+	}
+}
+
+func (l *testLogger) WithValues(kvs ...interface{}) logr.Logger {
+	newMap := make(map[string]interface{}, len(l.keyValues)+len(kvs)/2)
+	for k, v := range l.keyValues {
+		newMap[k] = v
+	}
+	for i := 0; i < len(kvs); i += 2 {
+		newMap[kvs[i].(string)] = kvs[i+1]
+	}
+	return &testLogger{
+		name:      l.name,
+		keyValues: newMap,
+		writer:    l.writer,
+	}
+}

controllers/horizontalrunnerautoscaler_controller.go

@@ -46,6 +46,8 @@ type HorizontalRunnerAutoscalerReconciler struct {
 	Log          logr.Logger
 	Recorder     record.EventRecorder
 	Scheme       *runtime.Scheme
+
+	CacheDuration time.Duration
 }
 
 // +kubebuilder:rbac:groups=actions.summerwind.dev,resources=runnerdeployments,verbs=get;list;watch;update;patch
@@ -79,13 +81,23 @@ func (r *HorizontalRunnerAutoscalerReconciler) Reconcile(req ctrl.Request) (ctrl
 		return ctrl.Result{}, nil
 	}
 
-	replicas, err := r.computeReplicas(rd, hra)
-	if err != nil {
-		r.Recorder.Event(&hra, corev1.EventTypeNormal, "RunnerAutoscalingFailure", err.Error())
+	var replicas *int
 
-		log.Error(err, "Could not compute replicas")
+	replicasFromCache := r.getDesiredReplicasFromCache(hra)
 
-		return ctrl.Result{}, err
+	if replicasFromCache != nil {
+		replicas = replicasFromCache
+	} else {
+		var err error
+
+		replicas, err = r.computeReplicas(rd, hra)
+		if err != nil {
+			r.Recorder.Event(&hra, corev1.EventTypeNormal, "RunnerAutoscalingFailure", err.Error())
+
+			log.Error(err, "Could not compute replicas")
+
+			return ctrl.Result{}, err
+		}
 	}
 
 	const defaultReplicas = 1
@@ -93,6 +105,18 @@ func (r *HorizontalRunnerAutoscalerReconciler) Reconcile(req ctrl.Request) (ctrl
 	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()
@@ -103,12 +127,12 @@ func (r *HorizontalRunnerAutoscalerReconciler) Reconcile(req ctrl.Request) (ctrl
 
 			return ctrl.Result{}, err
 		}
-
-		return ctrl.Result{}, err
 	}
 
+	var updated *v1alpha1.HorizontalRunnerAutoscaler
+
 	if hra.Status.DesiredReplicas == nil || *hra.Status.DesiredReplicas != *replicas {
-		updated := hra.DeepCopy()
+		updated = hra.DeepCopy()
 
 		if (hra.Status.DesiredReplicas == nil && *replicas > 1) ||
 			(hra.Status.DesiredReplicas != nil && *replicas > *hra.Status.DesiredReplicas) {
@@ -117,7 +141,37 @@ func (r *HorizontalRunnerAutoscalerReconciler) Reconcile(req ctrl.Request) (ctrl
 		}
 
 		updated.Status.DesiredReplicas = replicas
+	}
 
+	if replicasFromCache == 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)
+			}
+		}
+
+		var cacheDuration time.Duration
+
+		if r.CacheDuration > 0 {
+			cacheDuration = r.CacheDuration
+		} else {
+			cacheDuration = 10 * time.Minute
+		}
+
+		updated.Status.CacheEntries = append(updated.Status.CacheEntries, v1alpha1.CacheEntry{
+			Key:            v1alpha1.CacheEntryKeyDesiredReplicas,
+			Value:          *replicas,
+			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")
 

controllers/integration_test.go

@@ -2,6 +2,11 @@ package controllers
 
 import (
 	"context"
+	"github.com/google/go-github/v33/github"
+	github3 "github.com/google/go-github/v33/github"
+	github2 "github.com/summerwind/actions-runner-controller/github"
+	"net/http"
+	"net/http/httptest"
 	"time"
 
 	"github.com/summerwind/actions-runner-controller/github/fake"
@@ -30,6 +35,12 @@ var (
 	workflowRunsFor1Replicas = `{"total_count": 6, "workflow_runs":[{"status":"queued"}, {"status":"completed"}, {"status":"completed"}, {"status":"completed"}, {"status":"completed"}]}"`
 )
 
+var webhookServer *httptest.Server
+
+var ghClient *github2.Client
+
+var fakeRunnerList *fake.RunnersList
+
 // SetupIntegrationTest will set up a testing environment.
 // This includes:
 // * creating a Namespace to be used during the test
@@ -41,10 +52,13 @@ func SetupIntegrationTest(ctx context.Context) *testEnvironment {
 	ns := &corev1.Namespace{}
 
 	responses := &fake.FixedResponses{}
+	responses.ListRunners = fake.DefaultListRunnersHandler()
 	responses.ListRepositoryWorkflowRuns = &fake.Handler{
 		Status: 200,
 		Body:   workflowRunsFor3Replicas,
 	}
+	fakeRunnerList = fake.NewRunnersList()
+	responses.ListRunners = fakeRunnerList.HandleList()
 	fakeGithubServer := fake.NewServer(fake.WithFixedResponses(responses))
 
 	BeforeEach(func() {
@@ -59,9 +73,7 @@ func SetupIntegrationTest(ctx context.Context) *testEnvironment {
 		mgr, err := ctrl.NewManager(cfg, ctrl.Options{})
 		Expect(err).NotTo(HaveOccurred(), "failed to create manager")
 
-		runnersList = fake.NewRunnersList()
-		server = runnersList.GetServer()
-		ghClient := newGithubClient(server)
+		ghClient = newGithubClient(fakeGithubServer)
 
 		replicasetController := &RunnerReplicaSetReconciler{
 			Client:       mgr.GetClient(),
@@ -85,15 +97,30 @@ func SetupIntegrationTest(ctx context.Context) *testEnvironment {
 		client := newGithubClient(fakeGithubServer)
 
 		autoscalerController := &HorizontalRunnerAutoscalerReconciler{
-			Client:       mgr.GetClient(),
-			Scheme:       scheme.Scheme,
-			Log:          logf.Log,
-			GitHubClient: client,
-			Recorder:     mgr.GetEventRecorderFor("horizontalrunnerautoscaler-controller"),
+			Client:        mgr.GetClient(),
+			Scheme:        scheme.Scheme,
+			Log:           logf.Log,
+			GitHubClient:  client,
+			Recorder:      mgr.GetEventRecorderFor("horizontalrunnerautoscaler-controller"),
+			CacheDuration: 1 * time.Second,
 		}
 		err = autoscalerController.SetupWithManager(mgr)
 		Expect(err).NotTo(HaveOccurred(), "failed to setup controller")
 
+		autoscalerWebhook := &HorizontalRunnerAutoscalerGitHubWebhook{
+			Client:   mgr.GetClient(),
+			Scheme:   scheme.Scheme,
+			Log:      logf.Log,
+			Recorder: mgr.GetEventRecorderFor("horizontalrunnerautoscaler-controller"),
+		}
+		err = autoscalerWebhook.SetupWithManager(mgr)
+		Expect(err).NotTo(HaveOccurred(), "failed to setup autoscaler webhook")
+
+		mux := http.NewServeMux()
+		mux.HandleFunc("/", autoscalerWebhook.Handle)
+
+		webhookServer = httptest.NewServer(mux)
+
 		go func() {
 			defer GinkgoRecover()
 
@@ -106,6 +133,7 @@ func SetupIntegrationTest(ctx context.Context) *testEnvironment {
 		close(stopCh)
 
 		fakeGithubServer.Close()
+		webhookServer.Close()
 
 		err := k8sClient.Delete(ctx, ns)
 		Expect(err).NotTo(HaveOccurred(), "failed to delete test namespace")
@@ -114,7 +142,7 @@ func SetupIntegrationTest(ctx context.Context) *testEnvironment {
 	return &testEnvironment{Namespace: ns, Responses: responses}
 }
 
-var _ = Context("Inside of a new namespace", func() {
+var _ = Context("INTEGRATION: Inside of a new namespace", func() {
 	ctx := context.TODO()
 	env := SetupIntegrationTest(ctx)
 	ns := env.Namespace
@@ -235,8 +263,20 @@ var _ = Context("Inside of a new namespace", func() {
 						},
 						MinReplicas:                       intPtr(1),
 						MaxReplicas:                       intPtr(3),
-						ScaleDownDelaySecondsAfterScaleUp: nil,
+						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},
+							},
+						},
 					},
 				}
 
@@ -274,8 +314,33 @@ var _ = Context("Inside of a new namespace", func() {
 					time.Second*5, time.Millisecond*500).Should(BeEquivalentTo(3))
 			}
 
+			{
+				var runnerList actionsv1alpha1.RunnerList
+
+				err := k8sClient.List(ctx, &runnerList, client.InNamespace(ns.Name))
+				if err != nil {
+					logf.Log.Error(err, "list runners")
+				}
+
+				for i, r := range runnerList.Items {
+					fakeRunnerList.Add(&github3.Runner{
+						ID:     github.Int64(int64(i)),
+						Name:   github.String(r.Name),
+						OS:     github.String("linux"),
+						Status: github.String("online"),
+						Busy:   github.Bool(false),
+					})
+				}
+
+				rs, err := ghClient.ListRunners(context.Background(), "", "", "test/valid")
+				Expect(err).NotTo(HaveOccurred(), "verifying list fake runners response")
+				Expect(len(rs)).To(Equal(3), "count of fake list runners")
+			}
+
 			// Scale-down to 1 replica
 			{
+				time.Sleep(time.Second)
+
 				responses.ListRepositoryWorkflowRuns.Body = workflowRunsFor1Replicas
 
 				var hra actionsv1alpha1.HorizontalRunnerAutoscaler
@@ -308,7 +373,60 @@ var _ = Context("Inside of a new namespace", func() {
 
 						return *runnerSets.Items[0].Spec.Replicas
 					},
-					time.Second*5, time.Millisecond*500).Should(BeEquivalentTo(1))
+					time.Second*5, time.Millisecond*500).Should(BeEquivalentTo(1), "runners after HRA force update for scale-down")
+			}
+
+			{
+				resp, err := sendWebhook(webhookServer, "pull_request", &github.PullRequestEvent{
+					PullRequest: &github.PullRequest{
+						Base: &github.PullRequestBranch{
+							Ref: github.String("main"),
+						},
+					},
+					Repo: &github.Repository{
+						Name: github.String("test/valid"),
+						Organization: &github.Organization{
+							Name: github.String("test"),
+						},
+					},
+					Action: github.String("created"),
+				})
+
+				Expect(err).NotTo(HaveOccurred(), "failed to send pull_request event")
+
+				Expect(resp.StatusCode).To(Equal(200))
+			}
+
+			// Scale-up to 2 replicas
+			{
+				runnerSets := actionsv1alpha1.RunnerReplicaSetList{Items: []actionsv1alpha1.RunnerReplicaSet{}}
+
+				Eventually(
+					func() int {
+						err := k8sClient.List(ctx, &runnerSets, client.InNamespace(ns.Name))
+						if err != nil {
+							logf.Log.Error(err, "list runner sets")
+						}
+
+						return len(runnerSets.Items)
+					},
+					time.Second*5, time.Millisecond*500).Should(BeEquivalentTo(1), "runner sets after webhook")
+
+				Eventually(
+					func() int {
+						err := k8sClient.List(ctx, &runnerSets, client.InNamespace(ns.Name))
+						if err != nil {
+							logf.Log.Error(err, "list runner sets")
+						}
+
+						if len(runnerSets.Items) == 0 {
+							logf.Log.Info("No runnerreplicasets exist yet")
+							return -1
+						}
+
+						return *runnerSets.Items[0].Spec.Replicas
+					},
+					time.Second*5, time.Millisecond*500).Should(BeEquivalentTo(2), "runners after webhook")
 			}
 		})
 	})

controllers/runner_controller.go

@@ -18,12 +18,15 @@ package controllers
 
 import (
 	"context"
+	"errors"
 	"fmt"
+	gogithub "github.com/google/go-github/v33/github"
 	"github.com/summerwind/actions-runner-controller/hash"
 	"strings"
+	"time"
 
 	"github.com/go-logr/logr"
-	"k8s.io/apimachinery/pkg/api/errors"
+	kerrors "k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/client-go/tools/record"
 	ctrl "sigs.k8s.io/controller-runtime"
@@ -41,6 +44,8 @@ const (
 	finalizerName = "runner.actions.summerwind.dev"
 
 	LabelKeyPodTemplateHash = "pod-template-hash"
+
+	retryDelayOnGitHubAPIRateLimitError = 30 * time.Second
 )
 
 // RunnerReconciler reconciles a Runner object
@@ -95,9 +100,22 @@ func (r *RunnerReconciler) Reconcile(req ctrl.Request) (ctrl.Result, error) {
 
 		if removed {
 			if len(runner.Status.Registration.Token) > 0 {
-				ok, err := r.unregisterRunner(ctx, runner.Spec.Organization, runner.Spec.Repository, runner.Name)
+				ok, err := r.unregisterRunner(ctx, runner.Spec.Enterprise, runner.Spec.Organization, runner.Spec.Repository, runner.Name)
 				if err != nil {
-					log.Error(err, "Failed to unregister runner")
+					if errors.Is(err, &gogithub.RateLimitError{}) {
+						// We log the underlying error when we failed calling GitHub API to list or unregisters,
+						// or the runner is still busy.
+						log.Error(
+							err,
+							fmt.Sprintf(
+								"Failed to unregister runner due to GitHub API rate limits. Delaying retry for %s to avoid excessive GitHub API calls",
+								retryDelayOnGitHubAPIRateLimitError,
+							),
+						)
+
+						return ctrl.Result{RequeueAfter: retryDelayOnGitHubAPIRateLimitError}, err
+					}
+
 					return ctrl.Result{}, err
 				}
 
@@ -124,7 +142,7 @@ func (r *RunnerReconciler) Reconcile(req ctrl.Request) (ctrl.Result, error) {
 
 	var pod corev1.Pod
 	if err := r.Get(ctx, req.NamespacedName, &pod); err != nil {
-		if !errors.IsNotFound(err) {
+		if !kerrors.IsNotFound(err) {
 			return ctrl.Result{}, err
 		}
 
@@ -167,7 +185,39 @@ func (r *RunnerReconciler) Reconcile(req ctrl.Request) (ctrl.Result, error) {
 		}
 
 		if !pod.ObjectMeta.DeletionTimestamp.IsZero() {
-			return ctrl.Result{}, err
+			deletionTimeout := 1 * time.Minute
+			currentTime := time.Now()
+			deletionDidTimeout := currentTime.Sub(pod.DeletionTimestamp.Add(deletionTimeout)) > 0
+
+			if deletionDidTimeout {
+				log.Info(
+					"Pod failed to delete itself in a timely manner. "+
+						"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,
+					"currentTime", currentTime,
+					"configuredDeletionTimeout", deletionTimeout,
+				)
+
+				var force int64 = 0
+				// forcefully delete runner as we would otherwise get stuck if the node stays unreachable
+				if err := r.Delete(ctx, &pod, &client.DeleteOptions{GracePeriodSeconds: &force}); err != nil {
+					// probably
+					if !kerrors.IsNotFound(err) {
+						log.Error(err, "Failed to forcefully delete pod resource ...")
+						return ctrl.Result{}, err
+					}
+					// forceful deletion finally succeeded
+					return ctrl.Result{Requeue: true}, nil
+				}
+
+				r.Recorder.Event(&runner, corev1.EventTypeNormal, "PodDeleted", fmt.Sprintf("Forcefully deleted pod '%s'", pod.Name))
+				log.Info("Forcefully deleted runner pod", "repository", runner.Spec.Repository)
+				// give kube manager a little time to forcefully delete the stuck pod
+				return ctrl.Result{RequeueAfter: 3 * time.Second}, err
+			} else {
+				return ctrl.Result{}, err
+			}
 		}
 
 		if pod.Status.Phase == corev1.PodRunning {
@@ -194,10 +244,33 @@ func (r *RunnerReconciler) Reconcile(req ctrl.Request) (ctrl.Result, error) {
 			return ctrl.Result{}, err
 		}
 
-		runnerBusy, err := r.isRunnerBusy(ctx, runner.Spec.Organization, runner.Spec.Repository, runner.Name)
+		notRegistered := false
+
+		runnerBusy, err := r.GitHubClient.IsRunnerBusy(ctx, runner.Spec.Enterprise, runner.Spec.Organization, runner.Spec.Repository, runner.Name)
 		if err != nil {
-			log.Error(err, "Failed to check if runner is busy")
-			return ctrl.Result{}, nil
+			var e *github.RunnerNotFound
+			if errors.As(err, &e) {
+				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
+			} else {
+				var e *gogithub.RateLimitError
+				if errors.As(err, &e) {
+					// We log the underlying error when we failed calling GitHub API to list or unregisters,
+					// or the runner is still busy.
+					log.Error(
+						err,
+						fmt.Sprintf(
+							"Failed to check if runner is busy due to Github API rate limit. Retrying in %s to avoid excessive GitHub API calls",
+							retryDelayOnGitHubAPIRateLimitError,
+						),
+					)
+
+					return ctrl.Result{RequeueAfter: retryDelayOnGitHubAPIRateLimitError}, err
+				}
+
+				return ctrl.Result{}, err
+			}
 		}
 
 		// See the `newPod` function called above for more information
@@ -209,9 +282,27 @@ func (r *RunnerReconciler) Reconcile(req ctrl.Request) (ctrl.Result, error) {
 			restart = true
 		}
 
+		registrationTimeout := 10 * time.Minute
+		currentTime := time.Now()
+		registrationDidTimeout := currentTime.Sub(pod.CreationTimestamp.Add(registrationTimeout)) > 0
+
+		if notRegistered && registrationDidTimeout {
+			log.Info(
+				"Runner failed to register itself to GitHub in timely manner. "+
+					"Recreating the pod to see if it resolves the issue. "+
+					"CAUTION: If you see this a lot, you should investigate the root cause. "+
+					"See https://github.com/summerwind/actions-runner-controller/issues/288",
+				"podCreationTimestamp", pod.CreationTimestamp,
+				"currentTime", currentTime,
+				"configuredRegistrationTimeout", registrationTimeout,
+			)
+
+			restart = true
+		}
+
 		// Don't do anything if there's no need to restart the runner
 		if !restart {
-			return ctrl.Result{}, err
+			return ctrl.Result{}, nil
 		}
 
 		// Delete current pod if recreation is needed
@@ -227,23 +318,8 @@ func (r *RunnerReconciler) Reconcile(req ctrl.Request) (ctrl.Result, error) {
 	return ctrl.Result{}, nil
 }
 
-func (r *RunnerReconciler) isRunnerBusy(ctx context.Context, org, repo, name string) (bool, error) {
-	runners, err := r.GitHubClient.ListRunners(ctx, org, repo)
-	if err != nil {
-		return false, err
-	}
-
-	for _, runner := range runners {
-		if runner.GetName() == name {
-			return runner.GetBusy(), nil
-		}
-	}
-
-	return false, fmt.Errorf("runner not found")
-}
-
-func (r *RunnerReconciler) unregisterRunner(ctx context.Context, org, repo, name string) (bool, error) {
-	runners, err := r.GitHubClient.ListRunners(ctx, org, repo)
+func (r *RunnerReconciler) unregisterRunner(ctx context.Context, enterprise, org, repo, name string) (bool, error) {
+	runners, err := r.GitHubClient.ListRunners(ctx, enterprise, org, repo)
 	if err != nil {
 		return false, err
 	}
@@ -263,7 +339,7 @@ func (r *RunnerReconciler) unregisterRunner(ctx context.Context, org, repo, name
 		return false, nil
 	}
 
-	if err := r.GitHubClient.RemoveRunner(ctx, org, repo, id); err != nil {
+	if err := r.GitHubClient.RemoveRunner(ctx, enterprise, org, repo, id); err != nil {
 		return false, err
 	}
 
@@ -277,7 +353,7 @@ func (r *RunnerReconciler) updateRegistrationToken(ctx context.Context, runner v
 
 	log := r.Log.WithValues("runner", runner.Name)
 
-	rt, err := r.GitHubClient.GetRegistrationToken(ctx, runner.Spec.Organization, runner.Spec.Repository, runner.Name)
+	rt, err := r.GitHubClient.GetRegistrationToken(ctx, runner.Spec.Enterprise, runner.Spec.Organization, runner.Spec.Repository, runner.Name)
 	if err != nil {
 		r.Recorder.Event(&runner, corev1.EventTypeWarning, "FailedUpdateRegistrationToken", "Updating registration token failed")
 		log.Error(err, "Failed to get new registration token")
@@ -339,6 +415,10 @@ func (r *RunnerReconciler) newPod(runner v1alpha1.Runner) (corev1.Pod, error) {
 			Name:  "RUNNER_REPO",
 			Value: runner.Spec.Repository,
 		},
+		{
+			Name:  "RUNNER_ENTERPRISE",
+			Value: runner.Spec.Enterprise,
+		},
 		{
 			Name:  "RUNNER_LABELS",
 			Value: strings.Join(runner.Spec.Labels, ","),
@@ -504,6 +584,7 @@ func (r *RunnerReconciler) newPod(runner v1alpha1.Runner) (corev1.Pod, error) {
 			SecurityContext: &corev1.SecurityContext{
 				Privileged: &privileged,
 			},
+			Resources: runner.Spec.DockerdContainerResources,
 		})
 
 	}

controllers/runnerdeployment_controller.go

@@ -177,7 +177,7 @@ func (r *RunnerDeploymentReconciler) Reconcile(req ctrl.Request) (ctrl.Result, e
 			rs := oldSets[i]
 
 			if err := r.Client.Delete(ctx, &rs); err != nil {
-				log.Error(err, "Failed to delete runner resource")
+				log.Error(err, "Failed to delete runnerreplicaset resource")
 
 				return ctrl.Result{}, err
 			}

controllers/runnerreplicaset_controller.go

@@ -18,10 +18,13 @@ package controllers
 
 import (
 	"context"
+	"errors"
 	"fmt"
+	gogithub "github.com/google/go-github/v33/github"
+	"time"
 
 	"github.com/go-logr/logr"
-	"k8s.io/apimachinery/pkg/api/errors"
+	kerrors "k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/client-go/tools/record"
 	ctrl "sigs.k8s.io/controller-runtime"
@@ -65,7 +68,7 @@ func (r *RunnerReplicaSetReconciler) Reconcile(req ctrl.Request) (ctrl.Result, e
 
 	var allRunners v1alpha1.RunnerList
 	if err := r.List(ctx, &allRunners, client.InNamespace(req.Namespace)); err != nil {
-		if !errors.IsNotFound(err) {
+		if !kerrors.IsNotFound(err) {
 			return ctrl.Result{}, err
 		}
 	}
@@ -102,12 +105,51 @@ func (r *RunnerReplicaSetReconciler) Reconcile(req ctrl.Request) (ctrl.Result, e
 		// get runners that are currently not busy
 		var notBusy []v1alpha1.Runner
 		for _, runner := range myRunners {
-			busy, err := r.isRunnerBusy(ctx, runner.Spec.Organization, runner.Spec.Repository, runner.Name)
+			busy, err := r.GitHubClient.IsRunnerBusy(ctx, runner.Spec.Enterprise, runner.Spec.Organization, runner.Spec.Repository, runner.Name)
 			if err != nil {
-				log.Error(err, "Failed to check if runner is busy")
-				return ctrl.Result{}, err
-			}
-			if !busy {
+				notRegistered := false
+
+				var e *github.RunnerNotFound
+				if errors.As(err, &e) {
+					log.V(1).Info("Failed to check if runner is busy. Either this runner has never been successfully registered to GitHub or has not managed yet to, and therefore we prioritize it for deletion", "runnerName", runner.Name)
+					notRegistered = true
+				} else {
+					var e *gogithub.RateLimitError
+					if errors.As(err, &e) {
+						// We log the underlying error when we failed calling GitHub API to list or unregisters,
+						// or the runner is still busy.
+						log.Error(
+							err,
+							fmt.Sprintf(
+								"Failed to check if runner is busy due to GitHub API rate limit. Retrying in %s to avoid excessive GitHub API calls",
+								retryDelayOnGitHubAPIRateLimitError,
+							),
+						)
+
+						return ctrl.Result{RequeueAfter: retryDelayOnGitHubAPIRateLimitError}, err
+					}
+
+					return ctrl.Result{}, err
+				}
+
+				registrationTimeout := 15 * time.Minute
+				currentTime := time.Now()
+				registrationDidTimeout := currentTime.Sub(runner.CreationTimestamp.Add(registrationTimeout)) > 0
+
+				if notRegistered && registrationDidTimeout {
+					log.Info(
+						"Runner failed to register itself to GitHub in timely manner. "+
+							"Recreating the pod to see if it resolves the issue. "+
+							"CAUTION: If you see this a lot, you should investigate the root cause. "+
+							"See https://github.com/summerwind/actions-runner-controller/issues/288",
+						"runnerCreationTimestamp", runner.CreationTimestamp,
+						"currentTime", currentTime,
+						"configuredRegistrationTimeout", registrationTimeout,
+					)
+
+					notBusy = append(notBusy, runner)
+				}
+			} else if !busy {
 				notBusy = append(notBusy, runner)
 			}
 		}
@@ -117,7 +159,7 @@ func (r *RunnerReplicaSetReconciler) Reconcile(req ctrl.Request) (ctrl.Result, e
 		}
 
 		for i := 0; i < n; i++ {
-			if err := r.Client.Delete(ctx, &notBusy[i]); err != nil {
+			if err := r.Client.Delete(ctx, &notBusy[i]); client.IgnoreNotFound(err) != nil {
 				log.Error(err, "Failed to delete runner resource")
 
 				return ctrl.Result{}, err
@@ -186,19 +228,3 @@ func (r *RunnerReplicaSetReconciler) SetupWithManager(mgr ctrl.Manager) error {
 		Owns(&v1alpha1.Runner{}).
 		Complete(r)
 }
-
-func (r *RunnerReplicaSetReconciler) isRunnerBusy(ctx context.Context, org, repo, name string) (bool, error) {
-	runners, err := r.GitHubClient.ListRunners(ctx, org, repo)
-	r.Log.Info("runners", "github", runners)
-	if err != nil {
-		return false, err
-	}
-
-	for _, runner := range runners {
-		if runner.GetName() == name {
-			return runner.GetBusy(), nil
-		}
-	}
-
-	return false, fmt.Errorf("runner not found")
-}

controllers/suite_test.go

@@ -17,6 +17,8 @@ limitations under the License.
 package controllers
 
 import (
+	"github.com/onsi/ginkgo/config"
+	"os"
 	"path/filepath"
 	"testing"
 
@@ -43,6 +45,8 @@ var testEnv *envtest.Environment
 func TestAPIs(t *testing.T) {
 	RegisterFailHandler(Fail)
 
+	config.GinkgoConfig.FocusString = os.Getenv("GINKGO_FOCUS")
+
 	RunSpecsWithDefaultAndCustomReporters(t,
 		"Controller Suite",
 		[]Reporter{envtest.NewlineReporter{}})

github/fake/fake.go

@@ -24,6 +24,16 @@ const (
 `
 )
 
+type ListRunnersHandler struct {
+	Status int
+	Body   string
+}
+
+func (h *ListRunnersHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	w.WriteHeader(h.Status)
+	fmt.Fprintf(w, h.Body)
+}
+
 type Handler struct {
 	Status int
 	Body   string
@@ -92,12 +102,21 @@ func NewServer(opts ...Option) *httptest.Server {
 			Status: http.StatusBadRequest,
 			Body:   "",
 		},
+		"/enterprises/test/actions/runners/registration-token": &Handler{
+			Status: http.StatusCreated,
+			Body:   fmt.Sprintf("{\"token\": \"%s\", \"expires_at\": \"%s\"}", RegistrationToken, time.Now().Add(time.Hour*1).Format(time.RFC3339)),
+		},
+		"/enterprises/invalid/actions/runners/registration-token": &Handler{
+			Status: http.StatusOK,
+			Body:   fmt.Sprintf("{\"token\": \"%s\", \"expires_at\": \"%s\"}", RegistrationToken, time.Now().Add(time.Hour*1).Format(time.RFC3339)),
+		},
+		"/enterprises/error/actions/runners/registration-token": &Handler{
+			Status: http.StatusBadRequest,
+			Body:   "",
+		},
 
 		// For ListRunners
-		"/repos/test/valid/actions/runners": &Handler{
-			Status: http.StatusOK,
-			Body:   RunnersListBody,
-		},
+		"/repos/test/valid/actions/runners": config.FixedResponses.ListRunners,
 		"/repos/test/invalid/actions/runners": &Handler{
 			Status: http.StatusNoContent,
 			Body:   "",
@@ -118,6 +137,18 @@ func NewServer(opts ...Option) *httptest.Server {
 			Status: http.StatusBadRequest,
 			Body:   "",
 		},
+		"/enterprises/test/actions/runners": &Handler{
+			Status: http.StatusOK,
+			Body:   RunnersListBody,
+		},
+		"/enterprises/invalid/actions/runners": &Handler{
+			Status: http.StatusNoContent,
+			Body:   "",
+		},
+		"/enterprises/error/actions/runners": &Handler{
+			Status: http.StatusBadRequest,
+			Body:   "",
+		},
 
 		// For RemoveRunner
 		"/repos/test/valid/actions/runners/1": &Handler{
@@ -144,6 +175,18 @@ func NewServer(opts ...Option) *httptest.Server {
 			Status: http.StatusBadRequest,
 			Body:   "",
 		},
+		"/enterprises/test/actions/runners/1": &Handler{
+			Status: http.StatusNoContent,
+			Body:   "",
+		},
+		"/enterprises/invalid/actions/runners/1": &Handler{
+			Status: http.StatusOK,
+			Body:   "",
+		},
+		"/enterprises/error/actions/runners/1": &Handler{
+			Status: http.StatusBadRequest,
+			Body:   "",
+		},
 
 		// For auto-scaling based on the number of queued(pending) workflow runs
 		"/repos/test/valid/actions/runs": config.FixedResponses.ListRepositoryWorkflowRuns,
@@ -159,3 +202,10 @@ func NewServer(opts ...Option) *httptest.Server {
 
 	return httptest.NewServer(mux)
 }
+
+func DefaultListRunnersHandler() *ListRunnersHandler {
+	return &ListRunnersHandler{
+		Status: http.StatusOK,
+		Body:   RunnersListBody,
+	}
+}

github/fake/options.go

@@ -1,8 +1,11 @@
 package fake
 
+import "net/http"
+
 type FixedResponses struct {
 	ListRepositoryWorkflowRuns *Handler
 	ListWorkflowJobs           *MapHandler
+	ListRunners                http.Handler
 }
 
 type Option func(*ServerConfig)
@@ -25,6 +28,15 @@ func WithListWorkflowJobsResponse(status int, bodies map[int]string) Option {
 	}
 }
 
+func WithListRunnersResponse(status int, body string) Option {
+	return func(c *ServerConfig) {
+		c.FixedResponses.ListRunners = &ListRunnersHandler{
+			Status: status,
+			Body:   body,
+		}
+	}
+}
+
 func WithFixedResponses(responses *FixedResponses) Option {
 	return func(c *ServerConfig) {
 		c.FixedResponses = responses

github/fake/runners.go

@@ -29,15 +29,15 @@ func (r *RunnersList) Add(runner *github.Runner) {
 func (r *RunnersList) GetServer() *httptest.Server {
 	router := mux.NewRouter()
 
-	router.Handle("/repos/{owner}/{repo}/actions/runners", r.handleList())
+	router.Handle("/repos/{owner}/{repo}/actions/runners", r.HandleList())
 	router.Handle("/repos/{owner}/{repo}/actions/runners/{id}", r.handleRemove())
-	router.Handle("/orgs/{org}/actions/runners", r.handleList())
+	router.Handle("/orgs/{org}/actions/runners", r.HandleList())
 	router.Handle("/orgs/{org}/actions/runners/{id}", r.handleRemove())
 
 	return httptest.NewServer(router)
 }
 
-func (r *RunnersList) handleList() http.HandlerFunc {
+func (r *RunnersList) HandleList() http.HandlerFunc {
 	return func(w http.ResponseWriter, res *http.Request) {
 		j, err := json.Marshal(github.Runners{
 			TotalCount: len(r.runners),

github/github.go

@@ -11,6 +11,7 @@ import (
 
 	"github.com/bradleyfalzon/ghinstallation"
 	"github.com/google/go-github/v33/github"
+	"github.com/summerwind/actions-runner-controller/github/metrics"
 	"golang.org/x/oauth2"
 )
 
@@ -34,15 +35,9 @@ type Client struct {
 
 // NewClient creates a Github Client
 func (c *Config) NewClient() (*Client, error) {
-	var (
-		httpClient *http.Client
-		client     *github.Client
-	)
-	githubBaseURL := "https://github.com/"
+	var transport http.RoundTripper
 	if len(c.Token) > 0 {
-		httpClient = oauth2.NewClient(context.Background(), oauth2.StaticTokenSource(
-			&oauth2.Token{AccessToken: c.Token},
-		))
+		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)
 		if err != nil {
@@ -55,9 +50,13 @@ func (c *Config) NewClient() (*Client, error) {
 			}
 			tr.BaseURL = githubAPIURL
 		}
-		httpClient = &http.Client{Transport: tr}
+		transport = tr
 	}
+	transport = metrics.Transport{Transport: transport}
+	httpClient := &http.Client{Transport: transport}
 
+	var client *github.Client
+	var githubBaseURL string
 	if len(c.EnterpriseURL) > 0 {
 		var err error
 		client, err = github.NewEnterpriseClient(c.EnterpriseURL, c.EnterpriseURL, httpClient)
@@ -67,6 +66,7 @@ func (c *Config) NewClient() (*Client, error) {
 		githubBaseURL = fmt.Sprintf("%s://%s%s", client.BaseURL.Scheme, client.BaseURL.Host, strings.TrimSuffix(client.BaseURL.Path, "api/v3/"))
 	} else {
 		client = github.NewClient(httpClient)
+		githubBaseURL = "https://github.com/"
 	}
 
 	return &Client{
@@ -78,24 +78,24 @@ func (c *Config) NewClient() (*Client, error) {
 }
 
 // GetRegistrationToken returns a registration token tied with the name of repository and runner.
-func (c *Client) GetRegistrationToken(ctx context.Context, org, repo, name string) (*github.RegistrationToken, error) {
+func (c *Client) GetRegistrationToken(ctx context.Context, enterprise, org, repo, name string) (*github.RegistrationToken, error) {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 
-	key := getRegistrationKey(org, repo)
+	key := getRegistrationKey(org, repo, enterprise)
 	rt, ok := c.regTokens[key]
 
 	if ok && rt.GetExpiresAt().After(time.Now()) {
 		return rt, nil
 	}
 
-	owner, repo, err := getOwnerAndRepo(org, repo)
+	enterprise, owner, repo, err := getEnterpriseOrganisationAndRepo(enterprise, org, repo)
 
 	if err != nil {
 		return rt, err
 	}
 
-	rt, res, err := c.createRegistrationToken(ctx, owner, repo)
+	rt, res, err := c.createRegistrationToken(ctx, enterprise, owner, repo)
 
 	if err != nil {
 		return nil, fmt.Errorf("failed to create registration token: %v", err)
@@ -114,17 +114,17 @@ func (c *Client) GetRegistrationToken(ctx context.Context, org, repo, name strin
 }
 
 // RemoveRunner removes a runner with specified runner ID from repository.
-func (c *Client) RemoveRunner(ctx context.Context, org, repo string, runnerID int64) error {
-	owner, repo, err := getOwnerAndRepo(org, repo)
+func (c *Client) RemoveRunner(ctx context.Context, enterprise, org, repo string, runnerID int64) error {
+	enterprise, owner, repo, err := getEnterpriseOrganisationAndRepo(enterprise, org, repo)
 
 	if err != nil {
 		return err
 	}
 
-	res, err := c.removeRunner(ctx, owner, repo, runnerID)
+	res, err := c.removeRunner(ctx, enterprise, owner, repo, runnerID)
 
 	if err != nil {
-		return fmt.Errorf("failed to remove runner: %v", err)
+		return fmt.Errorf("failed to remove runner: %w", err)
 	}
 
 	if res.StatusCode != 204 {
@@ -135,8 +135,8 @@ func (c *Client) RemoveRunner(ctx context.Context, org, repo string, runnerID in
 }
 
 // ListRunners returns a list of runners of specified owner/repository name.
-func (c *Client) ListRunners(ctx context.Context, org, repo string) ([]*github.Runner, error) {
-	owner, repo, err := getOwnerAndRepo(org, repo)
+func (c *Client) ListRunners(ctx context.Context, enterprise, org, repo string) ([]*github.Runner, error) {
+	enterprise, owner, repo, err := getEnterpriseOrganisationAndRepo(enterprise, org, repo)
 
 	if err != nil {
 		return nil, err
@@ -146,10 +146,10 @@ func (c *Client) ListRunners(ctx context.Context, org, repo string) ([]*github.R
 
 	opts := github.ListOptions{PerPage: 10}
 	for {
-		list, res, err := c.listRunners(ctx, owner, repo, &opts)
+		list, res, err := c.listRunners(ctx, enterprise, owner, repo, &opts)
 
 		if err != nil {
-			return runners, fmt.Errorf("failed to list runners: %v", err)
+			return runners, fmt.Errorf("failed to list runners: %w", err)
 		}
 
 		runners = append(runners, list.Runners...)
@@ -174,49 +174,84 @@ func (c *Client) cleanup() {
 	}
 }
 
-// wrappers for github functions (switch between organization/repository mode)
+// wrappers for github functions (switch between enterprise/organization/repository mode)
 // so the calling functions don't need to switch and their code is a bit cleaner
 
-func (c *Client) createRegistrationToken(ctx context.Context, owner, repo string) (*github.RegistrationToken, *github.Response, error) {
+func (c *Client) createRegistrationToken(ctx context.Context, enterprise, org, repo string) (*github.RegistrationToken, *github.Response, error) {
 	if len(repo) > 0 {
-		return c.Client.Actions.CreateRegistrationToken(ctx, owner, repo)
-	}
-
-	return c.Client.Actions.CreateOrganizationRegistrationToken(ctx, owner)
-}
-
-func (c *Client) removeRunner(ctx context.Context, owner, repo string, runnerID int64) (*github.Response, error) {
-	if len(repo) > 0 {
-		return c.Client.Actions.RemoveRunner(ctx, owner, repo, runnerID)
-	}
-
-	return c.Client.Actions.RemoveOrganizationRunner(ctx, owner, runnerID)
-}
-
-func (c *Client) listRunners(ctx context.Context, owner, repo string, opts *github.ListOptions) (*github.Runners, *github.Response, error) {
-	if len(repo) > 0 {
-		return c.Client.Actions.ListRunners(ctx, owner, repo, opts)
-	}
-
-	return c.Client.Actions.ListOrganizationRunners(ctx, owner, opts)
-}
-
-// Validates owner and repo arguments. Both are optional, but at least one should be specified
-func getOwnerAndRepo(org, repo string) (string, string, error) {
-	if len(repo) > 0 {
-		return splitOwnerAndRepo(repo)
+		return c.Client.Actions.CreateRegistrationToken(ctx, org, repo)
 	}
 	if len(org) > 0 {
-		return org, "", nil
+		return c.Client.Actions.CreateOrganizationRegistrationToken(ctx, org)
 	}
-	return "", "", fmt.Errorf("organization and repository are both empty")
+	return c.Client.Enterprise.CreateRegistrationToken(ctx, enterprise)
 }
 
-func getRegistrationKey(org, repo string) string {
-	if len(org) > 0 {
-		return org
+func (c *Client) removeRunner(ctx context.Context, enterprise, org, repo string, runnerID int64) (*github.Response, error) {
+	if len(repo) > 0 {
+		return c.Client.Actions.RemoveRunner(ctx, org, repo, runnerID)
 	}
-	return repo
+	if len(org) > 0 {
+		return c.Client.Actions.RemoveOrganizationRunner(ctx, org, runnerID)
+	}
+	return c.Client.Enterprise.RemoveRunner(ctx, enterprise, runnerID)
+}
+
+func (c *Client) listRunners(ctx context.Context, enterprise, org, repo string, opts *github.ListOptions) (*github.Runners, *github.Response, error) {
+	if len(repo) > 0 {
+		return c.Client.Actions.ListRunners(ctx, org, repo, opts)
+	}
+	if len(org) > 0 {
+		return c.Client.Actions.ListOrganizationRunners(ctx, org, opts)
+	}
+	return c.Client.Enterprise.ListRunners(ctx, enterprise, opts)
+}
+
+func (c *Client) ListRepositoryWorkflowRuns(ctx context.Context, user string, repoName string) ([]*github.WorkflowRun, error) {
+	c.Client.Actions.ListRepositoryWorkflowRuns(ctx, user, repoName, nil)
+
+	var workflowRuns []*github.WorkflowRun
+
+	opts := github.ListWorkflowRunsOptions{
+		ListOptions: github.ListOptions{
+			PerPage: 100,
+		},
+	}
+
+	for {
+		list, res, err := c.Client.Actions.ListRepositoryWorkflowRuns(ctx, user, repoName, &opts)
+
+		if err != nil {
+			return workflowRuns, fmt.Errorf("failed to list workflow runs: %v", err)
+		}
+
+		workflowRuns = append(workflowRuns, list.WorkflowRuns...)
+		if res.NextPage == 0 {
+			break
+		}
+		opts.Page = res.NextPage
+	}
+
+	return workflowRuns, nil
+}
+
+// Validates enterprise, organisation and repo arguments. Both are optional, but at least one should be specified
+func getEnterpriseOrganisationAndRepo(enterprise, org, repo string) (string, string, string, error) {
+	if len(repo) > 0 {
+		owner, repository, err := splitOwnerAndRepo(repo)
+		return "", owner, repository, err
+	}
+	if len(org) > 0 {
+		return "", org, "", nil
+	}
+	if len(enterprise) > 0 {
+		return enterprise, "", "", nil
+	}
+	return "", "", "", fmt.Errorf("enterprise, organization and repository are all empty")
+}
+
+func getRegistrationKey(org, repo, enterprise string) string {
+	return fmt.Sprintf("org=%s,repo=%s,enterprise=%s", org, repo, enterprise)
 }
 
 func splitOwnerAndRepo(repo string) (string, string, error) {
@@ -244,3 +279,26 @@ func getEnterpriseApiUrl(baseURL string) (string, error) {
 	// Trim trailing slash, otherwise there's double slash added to token endpoint
 	return fmt.Sprintf("%s://%s%s", baseEndpoint.Scheme, baseEndpoint.Host, strings.TrimSuffix(baseEndpoint.Path, "/")), nil
 }
+
+type RunnerNotFound struct {
+	runnerName string
+}
+
+func (e *RunnerNotFound) Error() string {
+	return fmt.Sprintf("runner %q not found", e.runnerName)
+}
+
+func (r *Client) IsRunnerBusy(ctx context.Context, enterprise, org, repo, name string) (bool, error) {
+	runners, err := r.ListRunners(ctx, enterprise, org, repo)
+	if err != nil {
+		return false, err
+	}
+
+	for _, runner := range runners {
+		if runner.GetName() == name {
+			return runner.GetBusy(), nil
+		}
+	}
+
+	return false, &RunnerNotFound{runnerName: name}
+}

github/github_test.go

@@ -32,29 +32,36 @@ func newTestClient() *Client {
 }
 
 func TestMain(m *testing.M) {
-	server = fake.NewServer()
+	res := &fake.FixedResponses{
+		ListRunners: fake.DefaultListRunnersHandler(),
+	}
+	server = fake.NewServer(fake.WithFixedResponses(res))
 	defer server.Close()
 	m.Run()
 }
 
 func TestGetRegistrationToken(t *testing.T) {
 	tests := []struct {
-		org   string
-		repo  string
-		token string
-		err   bool
+		enterprise string
+		org        string
+		repo       string
+		token      string
+		err        bool
 	}{
-		{org: "", repo: "test/valid", token: fake.RegistrationToken, err: false},
-		{org: "", repo: "test/invalid", token: "", err: true},
-		{org: "", repo: "test/error", token: "", err: true},
-		{org: "test", repo: "", token: fake.RegistrationToken, err: false},
-		{org: "invalid", repo: "", token: "", err: true},
-		{org: "error", repo: "", token: "", err: true},
+		{enterprise: "", org: "", repo: "test/valid", token: fake.RegistrationToken, err: false},
+		{enterprise: "", org: "", repo: "test/invalid", token: "", err: true},
+		{enterprise: "", org: "", repo: "test/error", token: "", err: true},
+		{enterprise: "", org: "test", repo: "", token: fake.RegistrationToken, err: false},
+		{enterprise: "", org: "invalid", repo: "", token: "", err: true},
+		{enterprise: "", org: "error", repo: "", token: "", err: true},
+		{enterprise: "test", org: "", repo: "", token: fake.RegistrationToken, err: false},
+		{enterprise: "invalid", org: "", repo: "", token: "", err: true},
+		{enterprise: "error", org: "", repo: "", token: "", err: true},
 	}
 
 	client := newTestClient()
 	for i, tt := range tests {
-		rt, err := client.GetRegistrationToken(context.Background(), tt.org, tt.repo, "test")
+		rt, err := client.GetRegistrationToken(context.Background(), tt.enterprise, tt.org, tt.repo, "test")
 		if !tt.err && err != nil {
 			t.Errorf("[%d] unexpected error: %v", i, err)
 		}
@@ -66,22 +73,26 @@ func TestGetRegistrationToken(t *testing.T) {
 
 func TestListRunners(t *testing.T) {
 	tests := []struct {
-		org    string
-		repo   string
-		length int
-		err    bool
+		enterprise string
+		org        string
+		repo       string
+		length     int
+		err        bool
 	}{
-		{org: "", repo: "test/valid", length: 2, err: false},
-		{org: "", repo: "test/invalid", length: 0, err: true},
-		{org: "", repo: "test/error", length: 0, err: true},
-		{org: "test", repo: "", length: 2, err: false},
-		{org: "invalid", repo: "", length: 0, err: true},
-		{org: "error", repo: "", length: 0, err: true},
+		{enterprise: "", org: "", repo: "test/valid", length: 2, err: false},
+		{enterprise: "", org: "", repo: "test/invalid", length: 0, err: true},
+		{enterprise: "", org: "", repo: "test/error", length: 0, err: true},
+		{enterprise: "", org: "test", repo: "", length: 2, err: false},
+		{enterprise: "", org: "invalid", repo: "", length: 0, err: true},
+		{enterprise: "", org: "error", repo: "", length: 0, err: true},
+		{enterprise: "test", org: "", repo: "", length: 2, err: false},
+		{enterprise: "invalid", org: "", repo: "", length: 0, err: true},
+		{enterprise: "error", org: "", repo: "", length: 0, err: true},
 	}
 
 	client := newTestClient()
 	for i, tt := range tests {
-		runners, err := client.ListRunners(context.Background(), tt.org, tt.repo)
+		runners, err := client.ListRunners(context.Background(), tt.enterprise, tt.org, tt.repo)
 		if !tt.err && err != nil {
 			t.Errorf("[%d] unexpected error: %v", i, err)
 		}
@@ -93,21 +104,25 @@ func TestListRunners(t *testing.T) {
 
 func TestRemoveRunner(t *testing.T) {
 	tests := []struct {
-		org  string
-		repo string
-		err  bool
+		enterprise string
+		org        string
+		repo       string
+		err        bool
 	}{
-		{org: "", repo: "test/valid", err: false},
-		{org: "", repo: "test/invalid", err: true},
-		{org: "", repo: "test/error", err: true},
-		{org: "test", repo: "", err: false},
-		{org: "invalid", repo: "", err: true},
-		{org: "error", repo: "", err: true},
+		{enterprise: "", org: "", repo: "test/valid", err: false},
+		{enterprise: "", org: "", repo: "test/invalid", err: true},
+		{enterprise: "", org: "", repo: "test/error", err: true},
+		{enterprise: "", org: "test", repo: "", err: false},
+		{enterprise: "", org: "invalid", repo: "", err: true},
+		{enterprise: "", org: "error", repo: "", err: true},
+		{enterprise: "test", org: "", repo: "", err: false},
+		{enterprise: "invalid", org: "", repo: "", err: true},
+		{enterprise: "error", org: "", repo: "", err: true},
 	}
 
 	client := newTestClient()
 	for i, tt := range tests {
-		err := client.RemoveRunner(context.Background(), tt.org, tt.repo, int64(1))
+		err := client.RemoveRunner(context.Background(), tt.enterprise, tt.org, tt.repo, int64(1))
 		if !tt.err && err != nil {
 			t.Errorf("[%d] unexpected error: %v", i, err)
 		}

github/metrics/transport.go

@@ -0,0 +1,63 @@
+// Package metrics provides monitoring of the GitHub related metrics.
+//
+// This depends on the metrics exporter of kubebuilder.
+// See https://book.kubebuilder.io/reference/metrics.html for details.
+package metrics
+
+import (
+	"net/http"
+	"strconv"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"sigs.k8s.io/controller-runtime/pkg/metrics"
+)
+
+func init() {
+	metrics.Registry.MustRegister(metricRateLimit, metricRateLimitRemaining)
+}
+
+var (
+	// https://docs.github.com/en/rest/overview/resources-in-the-rest-api#rate-limiting
+	metricRateLimit = prometheus.NewGauge(
+		prometheus.GaugeOpts{
+			Name: "github_rate_limit",
+			Help: "The maximum number of requests you're permitted to make per hour",
+		},
+	)
+	metricRateLimitRemaining = prometheus.NewGauge(
+		prometheus.GaugeOpts{
+			Name: "github_rate_limit_remaining",
+			Help: "The number of requests remaining in the current rate limit window",
+		},
+	)
+)
+
+const (
+	// https://docs.github.com/en/rest/overview/resources-in-the-rest-api#rate-limiting
+	headerRateLimit          = "X-RateLimit-Limit"
+	headerRateLimitRemaining = "X-RateLimit-Remaining"
+)
+
+// Transport wraps a transport with metrics monitoring
+type Transport struct {
+	Transport http.RoundTripper
+}
+
+func (t Transport) RoundTrip(req *http.Request) (*http.Response, error) {
+	resp, err := t.Transport.RoundTrip(req)
+	if resp != nil {
+		parseResponse(resp)
+	}
+	return resp, err
+}
+
+func parseResponse(resp *http.Response) {
+	rateLimit, err := strconv.Atoi(resp.Header.Get(headerRateLimit))
+	if err == nil {
+		metricRateLimit.Set(float64(rateLimit))
+	}
+	rateLimitRemaining, err := strconv.Atoi(resp.Header.Get(headerRateLimitRemaining))
+	if err == nil {
+		metricRateLimitRemaining.Set(float64(rateLimitRemaining))
+	}
+}

go.mod

@@ -6,14 +6,12 @@ require (
 	github.com/bradleyfalzon/ghinstallation v1.1.1
 	github.com/davecgh/go-spew v1.1.1
 	github.com/go-logr/logr v0.1.0
-	github.com/google/go-github v17.0.0+incompatible // indirect
-	github.com/google/go-github/v32 v32.1.1-0.20200822031813-d57a3a84ba04
-	github.com/google/go-github/v33 v33.0.0
-	github.com/google/go-querystring v1.0.0
+	github.com/google/go-github/v33 v33.0.1-0.20210204004227-319dcffb518a
 	github.com/gorilla/mux v1.8.0
 	github.com/kelseyhightower/envconfig v1.4.0
 	github.com/onsi/ginkgo v1.8.0
 	github.com/onsi/gomega v1.5.0
+	github.com/prometheus/client_golang v0.9.2
 	github.com/stretchr/testify v1.4.0 // indirect
 	golang.org/x/oauth2 v0.0.0-20190604053449-0f29369cfe45
 	k8s.io/api v0.0.0-20190918155943-95b840bb6a1f

go.sum

@@ -116,14 +116,10 @@ github.com/google/go-cmp v0.3.0 h1:crn/baboCvb5fXaQ0IJ1SGTsTVrWpDsCWC8EGETZijY=
 github.com/google/go-cmp v0.3.0/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
 github.com/google/go-cmp v0.3.1 h1:Xye71clBPdm5HgqGwUkwhbynsUJZhDbS20FvLhQ2izg=
 github.com/google/go-cmp v0.3.1/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
-github.com/google/go-github v17.0.0+incompatible h1:N0LgJ1j65A7kfXrZnUDaYCs/Sf4rEjNlfyDHW9dolSY=
-github.com/google/go-github v17.0.0+incompatible/go.mod h1:zLgOLi98H3fifZn+44m+umXrS52loVEgC2AApnigrVQ=
 github.com/google/go-github/v29 v29.0.2 h1:opYN6Wc7DOz7Ku3Oh4l7prmkOMwEcQxpFtxdU8N8Pts=
 github.com/google/go-github/v29 v29.0.2/go.mod h1:CHKiKKPHJ0REzfwc14QMklvtHwCveD0PxlMjLlzAM5E=
-github.com/google/go-github/v32 v32.1.1-0.20200822031813-d57a3a84ba04 h1:wEYk2h/GwOhImcVjiTIceP88WxVbXw2F+ARYUQMEsfg=
-github.com/google/go-github/v32 v32.1.1-0.20200822031813-d57a3a84ba04/go.mod h1:rIEpZD9CTDQwDK9GDrtMTycQNA4JU3qBsCizh3q2WCI=
-github.com/google/go-github/v33 v33.0.0 h1:qAf9yP0qc54ufQxzwv+u9H0tiVOnPJxo0lI/JXqw3ZM=
-github.com/google/go-github/v33 v33.0.0/go.mod h1:GMdDnVZY/2TsWgp/lkYnpSAh6TrzhANBBwm6k6TTEXg=
+github.com/google/go-github/v33 v33.0.1-0.20210204004227-319dcffb518a h1:Z9Nzq8ntvvXCLnFGOkzzcD8HDOzOo+obuwE5oK85vNQ=
+github.com/google/go-github/v33 v33.0.1-0.20210204004227-319dcffb518a/go.mod h1:GMdDnVZY/2TsWgp/lkYnpSAh6TrzhANBBwm6k6TTEXg=
 github.com/google/go-querystring v1.0.0 h1:Xkwi/a1rcvNg1PPYe5vI8GbeBY/jrVuDX5ASuANWTrk=
 github.com/google/go-querystring v1.0.0/go.mod h1:odCYkC5MyYFN7vkCjXpyrEuKhc/BUO6wN/zVPAxq5ck=
 github.com/google/gofuzz v0.0.0-20161122191042-44d81051d367/go.mod h1:HP5RmnzzSNb993RKQDq4+1A4ia9nllfqcQFTQJedwGI=

main.go

@@ -144,10 +144,11 @@ func main() {
 	}
 
 	horizontalRunnerAutoscaler := &controllers.HorizontalRunnerAutoscalerReconciler{
-		Client:       mgr.GetClient(),
-		Log:          ctrl.Log.WithName("controllers").WithName("HorizontalRunnerAutoscaler"),
-		Scheme:       mgr.GetScheme(),
-		GitHubClient: ghClient,
+		Client:        mgr.GetClient(),
+		Log:           ctrl.Log.WithName("controllers").WithName("HorizontalRunnerAutoscaler"),
+		Scheme:        mgr.GetScheme(),
+		GitHubClient:  ghClient,
+		CacheDuration: syncPeriod - 10*time.Second,
 	}
 
 	if err = horizontalRunnerAutoscaler.SetupWithManager(mgr); err != nil {

runner/Dockerfile

@@ -83,7 +83,7 @@ RUN echo AGENT_TOOLSDIRECTORY=/opt/hostedtoolcache > .env \
   && chmod g+rwx /opt/hostedtoolcache
 
 COPY entrypoint.sh /
-COPY patched $RUNNER_ASSETS_DIR/patched
+COPY --chown=runner:docker patched $RUNNER_ASSETS_DIR/patched
 
 USER runner
 ENTRYPOINT ["/usr/local/bin/dumb-init", "--"]

runner/dindrunner.Dockerfile

@@ -104,7 +104,7 @@ RUN export ARCH=$(echo ${TARGETPLATFORM} | cut -d / -f2) \
 
 VOLUME /var/lib/docker
 
-COPY patched $RUNNER_ASSETS_DIR/patched
+COPY --chown=runner:docker patched $RUNNER_ASSETS_DIR/patched
 
 # No group definition, as that makes it harder to run docker.
 USER runner

runner/entrypoint.sh

@@ -16,14 +16,16 @@ if [ -z "${RUNNER_NAME}" ]; then
   exit 1
 fi
 
-if [ -n "${RUNNER_ORG}" ] && [ -n "${RUNNER_REPO}" ]; then
+if [ -n "${RUNNER_ORG}" ] && [ -n "${RUNNER_REPO}" ] && [ -n "${RUNNER_ENTERPRISE}" ]; then
   ATTACH="${RUNNER_ORG}/${RUNNER_REPO}"
 elif [ -n "${RUNNER_ORG}" ]; then
   ATTACH="${RUNNER_ORG}"
 elif [ -n "${RUNNER_REPO}" ]; then
   ATTACH="${RUNNER_REPO}"
+elif [ -n "${RUNNER_ENTERPRISE}" ]; then
+  ATTACH="enterprises/${RUNNER_ENTERPRISE}"
 else
-  echo "At least one of RUNNER_ORG or RUNNER_REPO must be set" 1>&2
+  echo "At least one of RUNNER_ORG or RUNNER_REPO or RUNNER_ENTERPRISE must be set" 1>&2
   exit 1
 fi