Fix token registration broken since v0.11.0 (#167)

Fixes #166

.github/workflows/build-runner.yml

@@ -1,22 +1,79 @@
 on:
+  pull_request:
+    branches:
+      - '**'
+    paths:
+      - 'runner/**'
+      - .github/workflows/build-runner.yml
   push:
     branches:
       - master
     paths:
-    - 'runner/**'
-
+      - runner/patched/*
+      - runner/Dockerfile
+      - runner/dindrunner.Dockerfile
+      - runner/entrypoint.sh
+      - .github/workflows/build-runner.yml
+name: Runner
 jobs:
   build:
     runs-on: ubuntu-latest
-    name: Build runner
+    name: Build
+    env:
+      RUNNER_VERSION: 2.273.5
+      DOCKER_VERSION: 19.03.12
+      DOCKERHUB_USERNAME: ${{ github.repository_owner }}
     steps:
       - name: Checkout
         uses: actions/checkout@v2
-    - name: Build container image
-      run: make docker-build
+
+      - name: Set up Docker Buildx
+        id: buildx
+        uses: crazy-max/ghaction-docker-buildx@v1
+        with:
+          buildx-version: latest
+
+      - name: Build Container Image
         working-directory: runner
-    - name: Docker Login
-      run: docker login -u summerwind -p ${{ secrets.DOCKER_ACCESS_TOKEN }}
-    - name: Push container image
-      run: make docker-push
+        if: ${{ github.event_name == 'pull_request' }}
+        run: |
+          docker buildx build \
+            --build-arg RUNNER_VERSION=${RUNNER_VERSION} \
+            --build-arg DOCKER_VERSION=${DOCKER_VERSION} \
+            --platform linux/amd64,linux/arm64 \
+            --tag ${DOCKERHUB_USERNAME}/actions-runner:v${RUNNER_VERSION} \
+            --tag ${DOCKERHUB_USERNAME}/actions-runner:latest \
+            -f Dockerfile .
+          docker buildx build \
+            --build-arg RUNNER_VERSION=${RUNNER_VERSION} \
+            --build-arg DOCKER_VERSION=${DOCKER_VERSION} \
+            --platform linux/amd64,linux/arm64 \
+            --tag ${DOCKERHUB_USERNAME}/actions-runner-dind:v${RUNNER_VERSION} \
+            --tag ${DOCKERHUB_USERNAME}/actions-runner-dind:latest \
+            -f dindrunner.Dockerfile .
+
+      - name: Login to GitHub Docker Registry
+        run: echo "${DOCKERHUB_PASSWORD}" | docker login -u "${DOCKERHUB_USERNAME}" --password-stdin
+        if: ${{ github.event_name == 'push' }}
+        env:
+          DOCKERHUB_USERNAME: ${{ github.repository_owner }}
+          DOCKERHUB_PASSWORD: ${{ secrets.DOCKER_ACCESS_TOKEN }}
+
+      - name: Build and Push Container Image
         working-directory: runner
+        if: ${{ github.event_name == 'push' }}
+        run: |
+          docker buildx build \
+            --build-arg RUNNER_VERSION=${RUNNER_VERSION} \
+            --build-arg DOCKER_VERSION=${DOCKER_VERSION} \
+            --platform linux/amd64,linux/arm64 \
+            --tag ${DOCKERHUB_USERNAME}/actions-runner:v${RUNNER_VERSION} \
+            --tag ${DOCKERHUB_USERNAME}/actions-runner:latest \
+            -f Dockerfile . --push
+          docker buildx build \
+            --build-arg RUNNER_VERSION=${RUNNER_VERSION} \
+            --build-arg DOCKER_VERSION=${DOCKER_VERSION} \
+            --platform linux/amd64,linux/arm64 \
+            --tag ${DOCKERHUB_USERNAME}/actions-runner-dind:v${RUNNER_VERSION} \
+            --tag ${DOCKERHUB_USERNAME}/actions-runner-dind:latest \
+            -f dindrunner.Dockerfile . --push

.github/workflows/release.yml

@@ -9,6 +9,7 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v2
+
       - name: Install tools
         run: |
           curl -L -O https://github.com/kubernetes-sigs/kubebuilder/releases/download/v2.2.0/kubebuilder_2.2.0_linux_amd64.tar.gz
@@ -19,15 +20,32 @@ jobs:
           curl -L -O https://github.com/tcnksm/ghr/releases/download/v0.13.0/ghr_v0.13.0_linux_amd64.tar.gz
           tar zxvf ghr_v0.13.0_linux_amd64.tar.gz
           sudo mv ghr_v0.13.0_linux_amd64/ghr /usr/local/bin
+
       - name: Set version
         run: echo "::set-env name=VERSION::$(cat ${GITHUB_EVENT_PATH} | jq -r '.release.tag_name')"
+
       - name: Upload artifacts
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: make github-release
-    - name: Build container image
-      run: make docker-build
-    - name: Docker Login
-      run: docker login -u summerwind -p ${{ secrets.DOCKER_ACCESS_TOKEN }}
-    - name: Push container image
-      run: make docker-push
+
+      - name: Set up Docker Buildx
+        id: buildx
+        uses: crazy-max/ghaction-docker-buildx@v1
+        with:
+          buildx-version: latest
+
+      - name: Login to GitHub Docker Registry
+        run: echo "${DOCKERHUB_PASSWORD}" | docker login -u "${DOCKERHUB_USERNAME}" --password-stdin
+        env:
+          DOCKERHUB_USERNAME: ${{ github.repository_owner }}
+          DOCKERHUB_PASSWORD: ${{ secrets.DOCKER_ACCESS_TOKEN }}
+
+      - name: Build Container Image
+        env:
+          DOCKERHUB_USERNAME: ${{ github.repository_owner }}
+        run: |
+          docker buildx build \
+            --platform linux/amd64,linux/arm64 \
+            --tag ${DOCKERHUB_USERNAME}/actions-runner-controller:${{ env.VERSION }} \
+            -f Dockerfile . --push

.github/workflows/test.yaml

@@ -1,15 +1,16 @@
+name: CI
+
 on:
-  push:
+  pull_request:
     branches:
       - master
     paths-ignore:
     - 'runner/**'
-    - '.github/**'
 
 jobs:
-  build:
+  test:
     runs-on: ubuntu-latest
-    name: Build
+    name: Test
     steps:
     - name: Checkout
       uses: actions/checkout@v2
@@ -20,9 +21,7 @@ jobs:
         sudo mv kubebuilder_2.2.0_linux_amd64 /usr/local/kubebuilder
     - name: Run tests
       run: make test
-    - name: Build container image
-      run: make docker-build
-    - name: Docker Login
-      run: docker login -u summerwind -p ${{ secrets.DOCKER_ACCESS_TOKEN }}
-    - name: Push container image
-      run: make docker-push
+    - name: Verify manifests are up-to-date
+      run: |
+        make manifests
+        git diff --exit-code

.github/workflows/wip.yml

@@ -0,0 +1,35 @@
+on:
+  push:
+    branches:
+      - master
+    paths-ignore:
+      - "runner/**"
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    name: release-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Set up Docker Buildx
+        id: buildx
+        uses: crazy-max/ghaction-docker-buildx@v1
+        with:
+          buildx-version: latest
+
+      - name: Login to GitHub Docker Registry
+        run: echo "${DOCKERHUB_PASSWORD}" | docker login -u "${DOCKERHUB_USERNAME}" --password-stdin
+        env:
+          DOCKERHUB_USERNAME: ${{ github.repository_owner }}
+          DOCKERHUB_PASSWORD: ${{ secrets.DOCKER_ACCESS_TOKEN }}
+
+      - name: Build Container Image
+        env:
+          DOCKERHUB_USERNAME: ${{ github.repository_owner }}
+        run: |
+          docker buildx build \
+            --platform linux/amd64,linux/arm64 \
+            --tag ${DOCKERHUB_USERNAME}/actions-runner-controller:latest \
+            -f Dockerfile . --push

Dockerfile

@@ -1,28 +1,37 @@
 # Build the manager binary
-FROM golang:1.13 as builder
+FROM golang:1.15 as builder
+
+ARG TARGETPLATFORM
 
 WORKDIR /workspace
+
+ENV GO111MODULE=on \
+  CGO_ENABLED=0
+
 # Copy the Go Modules manifests
-COPY go.mod go.mod
-COPY go.sum go.sum
+COPY go.mod go.sum ./
+
 # cache deps before building and copying source so that we don't need to re-download as much
 # and so that source changes don't invalidate our downloaded layer
 RUN go mod download
 
 # Copy the go source
-COPY main.go main.go
-COPY api/ api/
-COPY controllers/ controllers/
-COPY github/ github/
+COPY . .
 
 # Build
-RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 GO111MODULE=on go build -a -o manager main.go
+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
 
 # Use distroless as minimal base image to package the manager binary
 # Refer to https://github.com/GoogleContainerTools/distroless for more details
 FROM gcr.io/distroless/static:nonroot
+
 WORKDIR /
+
 COPY --from=builder /workspace/manager .
+
 USER nonroot:nonroot
 
 ENTRYPOINT ["/manager"]

Makefile

@@ -1,5 +1,8 @@
 NAME ?= summerwind/actions-runner-controller
 VERSION ?= latest
+# From https://github.com/VictoriaMetrics/operator/pull/44
+YAML_DROP=$(YQ) delete --inplace
+YAML_DROP_PREFIX=spec.validation.openAPIV3Schema.properties.spec.properties
 
 # Produce CRDs that work back to Kubernetes 1.11 (no version conversion)
 CRD_OPTIONS ?= "crd:trivialVersions=true"
@@ -11,6 +14,23 @@ else
 GOBIN=$(shell go env GOBIN)
 endif
 
+# default list of platforms for which multiarch image is built
+ifeq (${PLATFORMS}, )
+	export PLATFORMS="linux/amd64,linux/arm64"
+endif
+
+# if IMG_RESULT is unspecified, by default the image will be pushed to registry
+ifeq (${IMG_RESULT}, load)
+	export PUSH_ARG="--load"
+    # if load is specified, image will be built only for the build machine architecture.
+    export PLATFORMS="local"
+else ifeq (${IMG_RESULT}, cache)
+	# if cache is specified, image will only be available in the build cache, it won't be pushed or loaded
+	# therefore no PUSH_ARG will be specified
+else
+	export PUSH_ARG="--push"
+endif
+
 all: manager
 
 # Run tests
@@ -39,7 +59,9 @@ deploy: manifests
 	kustomize build config/default | kubectl apply -f -
 
 # Generate manifests e.g. CRD, RBAC etc.
-manifests: controller-gen
+manifests: manifests-118 fix118
+
+manifests-118: controller-gen
 	$(CONTROLLER_GEN) $(CRD_OPTIONS) rbac:roleName=manager-role webhook paths="./..." output:crd:artifacts:config=config/crd/bases
 
 # Run go fmt against code
@@ -50,6 +72,22 @@ fmt:
 vet:
 	go vet ./...
 
+# workaround for CRD issue with k8s 1.18 & controller-gen
+# ref: https://github.com/kubernetes/kubernetes/issues/91395
+fix118: yq
+	$(YAML_DROP) config/crd/bases/actions.summerwind.dev_runnerreplicasets.yaml $(YAML_DROP_PREFIX).template.properties.spec.properties.containers.items.properties
+	$(YAML_DROP) config/crd/bases/actions.summerwind.dev_runnerreplicasets.yaml $(YAML_DROP_PREFIX).template.properties.spec.properties.initContainers.items.properties
+	$(YAML_DROP) config/crd/bases/actions.summerwind.dev_runnerreplicasets.yaml $(YAML_DROP_PREFIX).template.properties.spec.properties.sidecarContainers.items.properties
+	$(YAML_DROP) config/crd/bases/actions.summerwind.dev_runnerreplicasets.yaml $(YAML_DROP_PREFIX).template.properties.spec.properties.ephemeralContainers.items.properties
+	$(YAML_DROP) config/crd/bases/actions.summerwind.dev_runnerdeployments.yaml $(YAML_DROP_PREFIX).template.properties.spec.properties.containers.items.properties
+	$(YAML_DROP) config/crd/bases/actions.summerwind.dev_runnerdeployments.yaml $(YAML_DROP_PREFIX).template.properties.spec.properties.initContainers.items.properties
+	$(YAML_DROP) config/crd/bases/actions.summerwind.dev_runnerdeployments.yaml $(YAML_DROP_PREFIX).template.properties.spec.properties.sidecarContainers.items.properties
+	$(YAML_DROP) config/crd/bases/actions.summerwind.dev_runnerdeployments.yaml $(YAML_DROP_PREFIX).template.properties.spec.properties.ephemeralContainers.items.properties
+	$(YAML_DROP) config/crd/bases/actions.summerwind.dev_runners.yaml $(YAML_DROP_PREFIX).containers.items.properties
+	$(YAML_DROP) config/crd/bases/actions.summerwind.dev_runners.yaml $(YAML_DROP_PREFIX).initContainers.items.properties
+	$(YAML_DROP) config/crd/bases/actions.summerwind.dev_runners.yaml $(YAML_DROP_PREFIX).sidecarContainers.items.properties
+	$(YAML_DROP) config/crd/bases/actions.summerwind.dev_runners.yaml $(YAML_DROP_PREFIX).ephemeralContainers.items.properties
+
 # Generate code
 generate: controller-gen
 	$(CONTROLLER_GEN) object:headerFile=./hack/boilerplate.go.txt paths="./..."
@@ -62,6 +100,18 @@ docker-build: test
 docker-push:
 	docker push ${NAME}:${VERSION}
 
+docker-buildx:
+	export DOCKER_CLI_EXPERIMENTAL=enabled
+	@if ! docker buildx ls | grep -q container-builder; then\
+		docker buildx create --platform ${PLATFORMS} --name container-builder --use;\
+	fi
+	docker buildx build --platform ${PLATFORMS} \
+		--build-arg RUNNER_VERSION=${RUNNER_VERSION} \
+		--build-arg DOCKER_VERSION=${DOCKER_VERSION} \
+		-t "${NAME}:${VERSION}" \
+		-f Dockerfile \
+		. ${PUSH_ARG}
+
 # Generate the release manifest file
 release: manifests
 	cd config/manager && kustomize edit set image controller=${NAME}:${VERSION}
@@ -76,15 +126,34 @@ github-release: release
 # download controller-gen if necessary
 controller-gen:
 ifeq (, $(shell which controller-gen))
+ifeq (, $(wildcard $(GOBIN)/controller-gen))
 	@{ \
 	set -e ;\
 	CONTROLLER_GEN_TMP_DIR=$$(mktemp -d) ;\
 	cd $$CONTROLLER_GEN_TMP_DIR ;\
 	go mod init tmp ;\
-	go get sigs.k8s.io/controller-tools/cmd/controller-gen@v0.2.4 ;\
+	go get sigs.k8s.io/controller-tools/cmd/controller-gen@v0.3.0 ;\
 	rm -rf $$CONTROLLER_GEN_TMP_DIR ;\
 	}
+endif
 CONTROLLER_GEN=$(GOBIN)/controller-gen
 else
 CONTROLLER_GEN=$(shell which controller-gen)
 endif
+
+# find or download yq
+# download yq if necessary
+# Use always go-version to get consistent line wraps etc.
+yq:
+ifeq (, $(wildcard $(GOBIN)/yq))
+	echo "Downloading yq"
+	@{ \
+	set -e ;\
+	YQ_TMP_DIR=$$(mktemp -d) ;\
+	cd $$YQ_TMP_DIR ;\
+	go mod init tmp ;\
+	go get github.com/mikefarah/yq/v3@3.4.0 ;\
+	rm -rf $$YQ_TMP_DIR ;\
+	}
+endif
+YQ=$(GOBIN)/yq

README.md

@@ -17,12 +17,22 @@ actions-runner-controller uses [cert-manager](https://cert-manager.io/docs/insta
 Install the custom resource and actions-runner-controller itself. This will create actions-runner-system namespace in your Kubernetes and deploy the required resources.
 
 ```
-$ kubectl apply -f https://github.com/summerwind/actions-runner-controller/releases/latest/download/actions-runner-controller.yaml
+kubectl apply -f https://github.com/summerwind/actions-runner-controller/releases/latest/download/actions-runner-controller.yaml
 ```
 
+### 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).
+
+```shell
+kubectl set env deploy controller-manager -c manager GITHUB_ENTERPRISE_URL=<GHEC/S URL>
+```
+
+[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.
+
 ## Setting up authentication with GitHub API
 
-There are two ways for actions-runner-controller to authenticate with the the GitHub API:
+There are two ways for actions-runner-controller to authenticate with the GitHub API:
 
 1. Using GitHub App.
 2. Using Personal Access Token.
@@ -37,7 +47,7 @@ You can create a GitHub App for either your account or any organization. If you
 
 If you want to create a GitHub App for your organization, replace the `:org` part of the following URL with your organization name before opening it. Then enter any unique name in the "GitHub App name" field, and hit the "Create GitHub App" button at the bottom of the page to create a GitHub App.
 
-- [Create GitHub Apps on your organization](https://github.com/organizations/:org/settings/apps/new?url=http://github.com/summerwind/actions-runner-controller&webhook_active=false&public=false&administration=write)
+- [Create GitHub Apps on your organization](https://github.com/organizations/:org/settings/apps/new?url=http://github.com/summerwind/actions-runner-controller&webhook_active=false&public=false&administration=write&organization_self_hosted_runners=write)
 
 You will see an *App ID* on the page of the GitHub App you created as follows, the value of this App ID will be used later.
 
@@ -58,7 +68,7 @@ When the installation is complete, you will be taken to a URL in one of the foll
 
 Finally, register the App ID (`APP_ID`), Installation ID (`INSTALLATION_ID`), and downloaded private key file (`PRIVATE_KEY_FILE_PATH`) to Kubernetes as Secret.
 
-```
+```shell
 $ kubectl create secret generic controller-manager \
     -n actions-runner-system \
     --from-literal=github_app_id=${APP_ID} \
@@ -80,8 +90,8 @@ Open the Create Token page from the following link, grant the `repo` and/or `adm
 
 Register the created token (`GITHUB_TOKEN`) as a Kubernetes secret.
 
-```
-$ kubectl create secret generic controller-manager \
+```shell
+kubectl create secret generic controller-manager \
     -n actions-runner-system \
     --from-literal=github_token=${GITHUB_TOKEN}
 ```
@@ -97,7 +107,7 @@ There are two ways to use this controller:
 
 To launch a single self-hosted runner, you need to create a manifest file includes *Runner* resource as follows. This example launches a self-hosted runner with name *example-runner* for the *summerwind/actions-runner-controller* repository.
 
-```
+```yaml
 # runner.yaml
 apiVersion: actions.summerwind.dev/v1alpha1
 kind: Runner
@@ -110,14 +120,14 @@ spec:
 
 Apply the created manifest file to your Kubernetes.
 
-```
+```shell
 $ kubectl apply -f runner.yaml
 runner.actions.summerwind.dev/example-runner created
 ```
 
 You can see that the Runner resource has been created.
 
-```
+```shell
 $ kubectl get runners
 NAME             REPOSITORY                             STATUS
 example-runner   summerwind/actions-runner-controller   Running
@@ -125,7 +135,7 @@ example-runner   summerwind/actions-runner-controller   Running
 
 You can also see that the runner pod has been running.
 
-```
+```shell
 $ kubectl get pods
 NAME           READY   STATUS    RESTARTS   AGE
 example-runner 2/2     Running   0          1m
@@ -135,13 +145,13 @@ The runner you created has been registered to your repository.
 
 <img width="756" alt="Actions tab in your repository settings" src="https://user-images.githubusercontent.com/230145/73618667-8cbf9700-466c-11ea-80b6-c67e6d3f70e7.png">
 
-Now your can use your self-hosted runner. See the [official documentation](https://help.github.com/en/actions/automating-your-workflow-with-github-actions/using-self-hosted-runners-in-a-workflow) on how to run a job with it.
+Now you can use your self-hosted runner. See the [official documentation](https://help.github.com/en/actions/automating-your-workflow-with-github-actions/using-self-hosted-runners-in-a-workflow) on how to run a job with it.
 
 ### Organization Runners
 
 To add the runner to an organization, you only need to replace the `repository` field with `organization`, so the runner will register itself to the organization.
 
-```
+```yaml
 # runner.yaml
 apiVersion: actions.summerwind.dev/v1alpha1
 kind: Runner
@@ -175,20 +185,104 @@ spec:
 
 Apply the manifest file to your cluster:
 
-```
+```shell
 $ kubectl apply -f runner.yaml
 runnerdeployment.actions.summerwind.dev/example-runnerdeploy created
 ```
 
 You can see that 2 runners have been created as specified by `replicas: 2`:
 
-```
+```shell
 $ kubectl get runners
 NAME                             REPOSITORY                             STATUS
 example-runnerdeploy2475h595fr   mumoshu/actions-runner-controller-ci   Running
 example-runnerdeploy2475ht2qbr   mumoshu/actions-runner-controller-ci   Running
 ```
 
+#### Autoscaling
+
+`RunnerDeployment` can scale the number of runners between `minReplicas` and `maxReplicas` fields, depending on pending workflow runs.
+
+In the below example, `actions-runner` checks for pending workflow runs for each sync period, and scale to e.g. 3 if there're 3 pending jobs at sync time.
+
+```yaml
+apiVersion: actions.summerwind.dev/v1alpha1
+kind: RunnerDeployment
+metadata:
+  name: example-runner-deployment
+spec:
+  template:
+    spec:
+      repository: summerwind/actions-runner-controller
+---
+apiVersion: actions.summerwind.dev/v1alpha1
+kind: HorizontalRunnerAutoscaler
+metadata:
+  name: example-runner-deployment-autoscaler
+spec:
+  scaleTargetRef:
+    name: example-runner-deployment
+  minReplicas: 1
+  maxReplicas: 3
+  metrics:
+  - type: TotalNumberOfQueuedAndInProgressWorkflowRuns
+    repositoryNames:
+    - summerwind/actions-runner-controller
+```
+
+Please also note that the sync period is set to 10 minutes by default and it's configurable via `--sync-period` flag.
+
+Additionally, the autoscaling feature has an anti-flapping option that prevents periodic loop of scaling up and down.
+By default, it doesn't scale down until the grace period of 10 minutes passes after a scale up. The grace period can be configured by setting `scaleDownDelaySecondsAfterScaleUp`:
+
+```yaml
+apiVersion: actions.summerwind.dev/v1alpha1
+kind: RunnerDeployment
+metadata:
+  name: example-runner-deployment
+spec:
+  template:
+    spec:
+      repository: summerwind/actions-runner-controller
+---
+apiVersion: actions.summerwind.dev/v1alpha1
+kind: HorizontalRunnerAutoscaler
+metadata:
+  name: example-runner-deployment-autoscaler
+spec:
+  scaleTargetRef:
+    name: example-runner-deployment
+  minReplicas: 1
+  maxReplicas: 3
+  scaleDownDelaySecondsAfterScaleOut: 60
+  metrics:
+  - type: TotalNumberOfQueuedAndInProgressWorkflowRuns
+    repositoryNames:
+    - summerwind/actions-runner-controller
+```
+
+## 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.
+
+```yaml
+# dindrunnerdeployment.yaml
+apiVersion: actions.summerwind.dev/v1alpha1
+kind: RunnerDeployment
+metadata:
+  name: example-dindrunnerdeploy
+spec:
+  replicas: 2
+  template:
+    spec:
+      image: summerwind/actions-runner-dind
+      dockerdWithinRunnerContainer: true
+      repository: mumoshu/actions-runner-controller-ci
+      env: []
+```
+
+This also helps with resources, as you don't need to give resources separately to docker and runner.
+
 ## Additional tweaks
 
 You can pass details through the spec selector. Here's an eg. of what you may like to do:
@@ -212,8 +306,8 @@ spec:
         operator: Exists
 
       repository: mumoshu/actions-runner-controller-ci
-      ImagePullPolicy: Always
       image: custom-image/actions-runner:latest
+      imagePullPolicy: Always
       resources:
         limits:
           cpu: "4.0"
@@ -221,6 +315,17 @@ spec:
         requests:
           cpu: "2.0"
           memory: "4Gi"
+      # If set to true, runner pod container only 1 container that's expected to be able to run docker, too.
+      # image summerwind/actions-runner-dind or custom one should be used with true -value
+      dockerdWithinRunnerContainer: false
+      # Valid if dockerdWithinRunnerContainer is not true
+      dockerdContainerResources:
+        limits:
+          cpu: "4.0"
+          memory: "8Gi"
+        requests:
+          cpu: "2.0"
+          memory: "4Gi"
       sidecarContainers:
         - name: mysql
           image: mysql:5.7
@@ -266,24 +371,43 @@ jobs:
     runs-on: custom-runner
 ```
 
-Note that if you specify `self-hosted` in your worlflow, then this will run your job on _any_ self-hosted runner, regardless of the labels that they have.
+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.
 
-## Softeware installed in the runner image
+## Runner Groups
 
-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
+Runner groups can be used to limit which repositories are able to use the GitHub Runner at an Organisation level.
+
+To add the runner to the group `NewGroup`, specify the group in your `Runner` or `RunnerDeployment` spec.
+
+```yaml
+# runnerdeployment.yaml
+apiVersion: actions.summerwind.dev/v1alpha1
+kind: RunnerDeployment
+metadata:
+  name: custom-runner
+spec:
+  replicas: 1
+  template:
+    spec:
+      group: NewGroup
+```
+
+## 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>
 
 The container image is based on Ubuntu 18.04, but it does not contain all of the software installed on the GitHub runners. It contains the following subset of packages from the GitHub runners:
 
-* Basic CLI packages
-* git (2.26)
-* docker
-* build-essentials
+- Basic CLI packages
+- git (2.26)
+- docker
+- build-essentials
 
 The virtual environments from GitHub contain a lot more software packages (different versions of Java, Node.js, Golang, .NET, etc) which are not provided in the runner image. Most of these have dedicated setup actions which allow the tools to be installed on-demand in a workflow, for example: `actions/setup-java` or `actions/setup-node`
 
 If there is a need to include packages in the runner image for which there is no setup action, then this can be achieved by building a custom container image for the runner. The easiest way is to start with the `summerwind/actions-runner` image and installing the extra dependencies directly in the docker image:
 
-```yaml
+```shell
 FROM summerwind/actions-runner:v2.169.1
 
 RUN sudo apt update -y \
@@ -302,3 +426,15 @@ spec:
   repository: summerwind/actions-runner-controller
   image: YOUR_CUSTOM_DOCKER_IMAGE
 ```
+
+# Alternatives
+
+The following is a list of alternative solutions that may better fit you depending on your use-case:
+
+- <https://github.com/evryfs/github-actions-runner-operator/>
+
+Although the situation can change over time, as of writing this sentence, the benefits of using `actions-runner-controller` over the alternatives are:
+
+- `actions-runner-controller` has the ability to autoscale runners based on number of pending/progressing jobs (#99)
+- `actions-runner-controller` is able to gracefully stop runners (#103)
+- `actions-runner-controller` has ARM support

api/v1alpha1/horizontalrunnerautoscaler_types.go

@@ -0,0 +1,102 @@
+/*
+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 v1alpha1
+
+import (
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+// HorizontalRunnerAutoscalerSpec defines the desired state of HorizontalRunnerAutoscaler
+type HorizontalRunnerAutoscalerSpec struct {
+	// ScaleTargetRef sis the reference to scaled resource like RunnerDeployment
+	ScaleTargetRef ScaleTargetRef `json:"scaleTargetRef,omitempty"`
+
+	// MinReplicas is the minimum number of replicas the deployment is allowed to scale
+	// +optional
+	MinReplicas *int `json:"minReplicas,omitempty"`
+
+	// MinReplicas is the maximum number of replicas the deployment is allowed to scale
+	// +optional
+	MaxReplicas *int `json:"maxReplicas,omitempty"`
+
+	// ScaleDownDelaySecondsAfterScaleUp is the approximate delay for a scale down followed by a scale up
+	// Used to prevent flapping (down->up->down->... loop)
+	// +optional
+	ScaleDownDelaySecondsAfterScaleUp *int `json:"scaleDownDelaySecondsAfterScaleOut,omitempty"`
+
+	// Metrics is the collection of various metric targets to calculate desired number of runners
+	// +optional
+	Metrics []MetricSpec `json:"metrics,omitempty"`
+}
+
+type ScaleTargetRef struct {
+	Name string `json:"name,omitempty"`
+}
+
+type MetricSpec struct {
+	// Type is the type of metric to be used for autoscaling.
+	// The only supported Type is TotalNumberOfQueuedAndInProgressWorkflowRuns
+	Type string `json:"type,omitempty"`
+
+	// RepositoryNames is the list of repository names to be used for calculating the metric.
+	// For example, a repository name is the REPO part of `github.com/USER/REPO`.
+	// +optional
+	RepositoryNames []string `json:"repositoryNames,omitempty"`
+}
+
+type HorizontalRunnerAutoscalerStatus struct {
+	// ObservedGeneration is the most recent generation observed for the target. It corresponds to e.g.
+	// RunnerDeployment's generation, which is updated on mutation by the API Server.
+	// +optional
+	ObservedGeneration int64 `json:"observedGeneration,omitempty"`
+
+	// DesiredReplicas is the total number of desired, non-terminated and latest pods to be set for the primary RunnerSet
+	// This doesn't include outdated pods while upgrading the deployment and replacing the runnerset.
+	// +optional
+	DesiredReplicas *int `json:"desiredReplicas,omitempty"`
+
+	// +optional
+	LastSuccessfulScaleOutTime *metav1.Time `json:"lastSuccessfulScaleOutTime,omitempty"`
+}
+
+// +kubebuilder:object:root=true
+// +kubebuilder:subresource:status
+// +kubebuilder:printcolumn:JSONPath=".spec.minReplicas",name=Min,type=number
+// +kubebuilder:printcolumn:JSONPath=".spec.maxReplicas",name=Max,type=number
+// +kubebuilder:printcolumn:JSONPath=".status.desiredReplicas",name=Desired,type=number
+
+// HorizontalRunnerAutoscaler is the Schema for the horizontalrunnerautoscaler API
+type HorizontalRunnerAutoscaler struct {
+	metav1.TypeMeta   `json:",inline"`
+	metav1.ObjectMeta `json:"metadata,omitempty"`
+
+	Spec   HorizontalRunnerAutoscalerSpec   `json:"spec,omitempty"`
+	Status HorizontalRunnerAutoscalerStatus `json:"status,omitempty"`
+}
+
+// +kubebuilder:object:root=true
+
+// HorizontalRunnerAutoscalerList contains a list of HorizontalRunnerAutoscaler
+type HorizontalRunnerAutoscalerList struct {
+	metav1.TypeMeta `json:",inline"`
+	metav1.ListMeta `json:"metadata,omitempty"`
+	Items           []HorizontalRunnerAutoscaler `json:"items"`
+}
+
+func init() {
+	SchemeBuilder.Register(&HorizontalRunnerAutoscaler{}, &HorizontalRunnerAutoscalerList{})
+}

api/v1alpha1/runner_types.go

@@ -36,9 +36,14 @@ type RunnerSpec struct {
 	// +optional
 	Labels []string `json:"labels,omitempty"`
 
+	// +optional
+	Group string `json:"group,omitempty"`
+
 	// +optional
 	Containers []corev1.Container `json:"containers,omitempty"`
 	// +optional
+	DockerdContainerResources corev1.ResourceRequirements `json:"dockerdContainerResources,omitempty"`
+	// +optional
 	Resources corev1.ResourceRequirements `json:"resources,omitempty"`
 	// +optional
 	VolumeMounts []corev1.VolumeMount `json:"volumeMounts,omitempty"`
@@ -48,6 +53,8 @@ type RunnerSpec struct {
 	// +optional
 	Image string `json:"image"`
 	// +optional
+	ImagePullPolicy corev1.PullPolicy `json:"imagePullPolicy,omitempty"`
+	// +optional
 	Env []corev1.EnvVar `json:"env,omitempty"`
 
 	// +optional
@@ -75,6 +82,8 @@ type RunnerSpec struct {
 	EphemeralContainers []corev1.EphemeralContainer `json:"ephemeralContainers,omitempty"`
 	// +optional
 	TerminationGracePeriodSeconds *int64 `json:"terminationGracePeriodSeconds,omitempty"`
+	// +optional
+	DockerdWithinRunnerContainer *bool `json:"dockerdWithinRunnerContainer,omitempty"`
 }
 
 // ValidateRepository validates repository field.

api/v1alpha1/runnerdeployment_types.go

@@ -20,9 +20,14 @@ import (
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
 
+const (
+	AutoscalingMetricTypeTotalNumberOfQueuedAndInProgressWorkflowRuns = "TotalNumberOfQueuedAndInProgressWorkflowRuns"
+)
+
 // RunnerReplicaSetSpec defines the desired state of RunnerDeployment
 type RunnerDeploymentSpec struct {
-	Replicas *int `json:"replicas"`
+	// +optional
+	Replicas *int `json:"replicas,omitempty"`
 
 	Template RunnerTemplate `json:"template"`
 }
@@ -30,6 +35,11 @@ type RunnerDeploymentSpec struct {
 type RunnerDeploymentStatus struct {
 	AvailableReplicas int `json:"availableReplicas"`
 	ReadyReplicas     int `json:"readyReplicas"`
+
+	// Replicas is the total number of desired, non-terminated and latest pods to be set for the primary RunnerSet
+	// This doesn't include outdated pods while upgrading the deployment and replacing the runnerset.
+	// +optional
+	Replicas *int `json:"desiredReplicas,omitempty"`
 }
 
 // +kubebuilder:object:root=true

api/v1alpha1/zz_generated.deepcopy.go

@@ -25,6 +25,147 @@ 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 *HorizontalRunnerAutoscaler) DeepCopyInto(out *HorizontalRunnerAutoscaler) {
+	*out = *in
+	out.TypeMeta = in.TypeMeta
+	in.ObjectMeta.DeepCopyInto(&out.ObjectMeta)
+	in.Spec.DeepCopyInto(&out.Spec)
+	in.Status.DeepCopyInto(&out.Status)
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new HorizontalRunnerAutoscaler.
+func (in *HorizontalRunnerAutoscaler) DeepCopy() *HorizontalRunnerAutoscaler {
+	if in == nil {
+		return nil
+	}
+	out := new(HorizontalRunnerAutoscaler)
+	in.DeepCopyInto(out)
+	return out
+}
+
+// DeepCopyObject is an autogenerated deepcopy function, copying the receiver, creating a new runtime.Object.
+func (in *HorizontalRunnerAutoscaler) DeepCopyObject() runtime.Object {
+	if c := in.DeepCopy(); c != nil {
+		return c
+	}
+	return nil
+}
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *HorizontalRunnerAutoscalerList) DeepCopyInto(out *HorizontalRunnerAutoscalerList) {
+	*out = *in
+	out.TypeMeta = in.TypeMeta
+	in.ListMeta.DeepCopyInto(&out.ListMeta)
+	if in.Items != nil {
+		in, out := &in.Items, &out.Items
+		*out = make([]HorizontalRunnerAutoscaler, len(*in))
+		for i := range *in {
+			(*in)[i].DeepCopyInto(&(*out)[i])
+		}
+	}
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new HorizontalRunnerAutoscalerList.
+func (in *HorizontalRunnerAutoscalerList) DeepCopy() *HorizontalRunnerAutoscalerList {
+	if in == nil {
+		return nil
+	}
+	out := new(HorizontalRunnerAutoscalerList)
+	in.DeepCopyInto(out)
+	return out
+}
+
+// DeepCopyObject is an autogenerated deepcopy function, copying the receiver, creating a new runtime.Object.
+func (in *HorizontalRunnerAutoscalerList) DeepCopyObject() runtime.Object {
+	if c := in.DeepCopy(); c != nil {
+		return c
+	}
+	return nil
+}
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *HorizontalRunnerAutoscalerSpec) DeepCopyInto(out *HorizontalRunnerAutoscalerSpec) {
+	*out = *in
+	out.ScaleTargetRef = in.ScaleTargetRef
+	if in.MinReplicas != nil {
+		in, out := &in.MinReplicas, &out.MinReplicas
+		*out = new(int)
+		**out = **in
+	}
+	if in.MaxReplicas != nil {
+		in, out := &in.MaxReplicas, &out.MaxReplicas
+		*out = new(int)
+		**out = **in
+	}
+	if in.ScaleDownDelaySecondsAfterScaleUp != nil {
+		in, out := &in.ScaleDownDelaySecondsAfterScaleUp, &out.ScaleDownDelaySecondsAfterScaleUp
+		*out = new(int)
+		**out = **in
+	}
+	if in.Metrics != nil {
+		in, out := &in.Metrics, &out.Metrics
+		*out = make([]MetricSpec, len(*in))
+		for i := range *in {
+			(*in)[i].DeepCopyInto(&(*out)[i])
+		}
+	}
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new HorizontalRunnerAutoscalerSpec.
+func (in *HorizontalRunnerAutoscalerSpec) DeepCopy() *HorizontalRunnerAutoscalerSpec {
+	if in == nil {
+		return nil
+	}
+	out := new(HorizontalRunnerAutoscalerSpec)
+	in.DeepCopyInto(out)
+	return out
+}
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *HorizontalRunnerAutoscalerStatus) DeepCopyInto(out *HorizontalRunnerAutoscalerStatus) {
+	*out = *in
+	if in.DesiredReplicas != nil {
+		in, out := &in.DesiredReplicas, &out.DesiredReplicas
+		*out = new(int)
+		**out = **in
+	}
+	if in.LastSuccessfulScaleOutTime != nil {
+		in, out := &in.LastSuccessfulScaleOutTime, &out.LastSuccessfulScaleOutTime
+		*out = (*in).DeepCopy()
+	}
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new HorizontalRunnerAutoscalerStatus.
+func (in *HorizontalRunnerAutoscalerStatus) DeepCopy() *HorizontalRunnerAutoscalerStatus {
+	if in == nil {
+		return nil
+	}
+	out := new(HorizontalRunnerAutoscalerStatus)
+	in.DeepCopyInto(out)
+	return out
+}
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *MetricSpec) DeepCopyInto(out *MetricSpec) {
+	*out = *in
+	if in.RepositoryNames != nil {
+		in, out := &in.RepositoryNames, &out.RepositoryNames
+		*out = make([]string, len(*in))
+		copy(*out, *in)
+	}
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new MetricSpec.
+func (in *MetricSpec) DeepCopy() *MetricSpec {
+	if in == nil {
+		return nil
+	}
+	out := new(MetricSpec)
+	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
@@ -58,7 +199,7 @@ func (in *RunnerDeployment) DeepCopyInto(out *RunnerDeployment) {
 	out.TypeMeta = in.TypeMeta
 	in.ObjectMeta.DeepCopyInto(&out.ObjectMeta)
 	in.Spec.DeepCopyInto(&out.Spec)
-	out.Status = in.Status
+	in.Status.DeepCopyInto(&out.Status)
 }
 
 // DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new RunnerDeployment.
@@ -135,6 +276,11 @@ func (in *RunnerDeploymentSpec) DeepCopy() *RunnerDeploymentSpec {
 // DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
 func (in *RunnerDeploymentStatus) DeepCopyInto(out *RunnerDeploymentStatus) {
 	*out = *in
+	if in.Replicas != nil {
+		in, out := &in.Replicas, &out.Replicas
+		*out = new(int)
+		**out = **in
+	}
 }
 
 // DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new RunnerDeploymentStatus.
@@ -289,6 +435,7 @@ func (in *RunnerSpec) DeepCopyInto(out *RunnerSpec) {
 			(*in)[i].DeepCopyInto(&(*out)[i])
 		}
 	}
+	in.DockerdContainerResources.DeepCopyInto(&out.DockerdContainerResources)
 	in.Resources.DeepCopyInto(&out.Resources)
 	if in.VolumeMounts != nil {
 		in, out := &in.VolumeMounts, &out.VolumeMounts
@@ -378,6 +525,11 @@ func (in *RunnerSpec) DeepCopyInto(out *RunnerSpec) {
 		*out = new(int64)
 		**out = **in
 	}
+	if in.DockerdWithinRunnerContainer != nil {
+		in, out := &in.DockerdWithinRunnerContainer, &out.DockerdWithinRunnerContainer
+		*out = new(bool)
+		**out = **in
+	}
 }
 
 // DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new RunnerSpec.
@@ -443,3 +595,18 @@ func (in *RunnerTemplate) DeepCopy() *RunnerTemplate {
 	in.DeepCopyInto(out)
 	return out
 }
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *ScaleTargetRef) DeepCopyInto(out *ScaleTargetRef) {
+	*out = *in
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new ScaleTargetRef.
+func (in *ScaleTargetRef) DeepCopy() *ScaleTargetRef {
+	if in == nil {
+		return nil
+	}
+	out := new(ScaleTargetRef)
+	in.DeepCopyInto(out)
+	return out
+}

config/certmanager/certificate.yaml

@@ -1,7 +1,7 @@
 # The following manifests contain a self-signed issuer CR and a certificate CR.
 # More document can be found at https://docs.cert-manager.io
 # WARNING: Targets CertManager 0.11 check https://docs.cert-manager.io/en/latest/tasks/upgrading/index.html for breaking changes
-apiVersion: cert-manager.io/v1alpha2
+apiVersion: cert-manager.io/v1
 kind: Issuer
 metadata:
   name: selfsigned-issuer
@@ -9,7 +9,7 @@ metadata:
 spec:
   selfSigned: {}
 ---
-apiVersion: cert-manager.io/v1alpha2
+apiVersion: cert-manager.io/v1
 kind: Certificate
 metadata:
   name: serving-cert  # this name should match the one appeared in kustomizeconfig.yaml

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

@@ -0,0 +1,118 @@
+
+---
+apiVersion: apiextensions.k8s.io/v1beta1
+kind: CustomResourceDefinition
+metadata:
+  annotations:
+    controller-gen.kubebuilder.io/version: v0.3.0
+  creationTimestamp: null
+  name: horizontalrunnerautoscalers.actions.summerwind.dev
+spec:
+  additionalPrinterColumns:
+  - JSONPath: .spec.minReplicas
+    name: Min
+    type: number
+  - JSONPath: .spec.maxReplicas
+    name: Max
+    type: number
+  - JSONPath: .status.desiredReplicas
+    name: Desired
+    type: number
+  group: actions.summerwind.dev
+  names:
+    kind: HorizontalRunnerAutoscaler
+    listKind: HorizontalRunnerAutoscalerList
+    plural: horizontalrunnerautoscalers
+    singular: horizontalrunnerautoscaler
+  scope: Namespaced
+  subresources:
+    status: {}
+  validation:
+    openAPIV3Schema:
+      description: HorizontalRunnerAutoscaler is the Schema for the horizontalrunnerautoscaler
+        API
+      properties:
+        apiVersion:
+          description: 'APIVersion defines the versioned schema of this representation
+            of an object. Servers should convert recognized schemas to the latest
+            internal value, and may reject unrecognized values. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#resources'
+          type: string
+        kind:
+          description: 'Kind is a string value representing the REST resource this
+            object represents. Servers may infer this from the endpoint the client
+            submits requests to. Cannot be updated. In CamelCase. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#types-kinds'
+          type: string
+        metadata:
+          type: object
+        spec:
+          description: HorizontalRunnerAutoscalerSpec defines the desired state of
+            HorizontalRunnerAutoscaler
+          properties:
+            maxReplicas:
+              description: MinReplicas is the maximum number of replicas the deployment
+                is allowed to scale
+              type: integer
+            metrics:
+              description: Metrics is the collection of various metric targets to
+                calculate desired number of runners
+              items:
+                properties:
+                  repositoryNames:
+                    description: RepositoryNames is the list of repository names to
+                      be used for calculating the metric. For example, a repository
+                      name is the REPO part of `github.com/USER/REPO`.
+                    items:
+                      type: string
+                    type: array
+                  type:
+                    description: Type is the type of metric to be used for autoscaling.
+                      The only supported Type is TotalNumberOfQueuedAndInProgressWorkflowRuns
+                    type: string
+                type: object
+              type: array
+            minReplicas:
+              description: MinReplicas is the minimum number of replicas the deployment
+                is allowed to scale
+              type: integer
+            scaleDownDelaySecondsAfterScaleOut:
+              description: ScaleDownDelaySecondsAfterScaleUp is the approximate delay
+                for a scale down followed by a scale up Used to prevent flapping (down->up->down->...
+                loop)
+              type: integer
+            scaleTargetRef:
+              description: ScaleTargetRef sis the reference to scaled resource like
+                RunnerDeployment
+              properties:
+                name:
+                  type: string
+              type: object
+          type: object
+        status:
+          properties:
+            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
+                outdated pods while upgrading the deployment and replacing the runnerset.
+              type: integer
+            lastSuccessfulScaleOutTime:
+              format: date-time
+              type: string
+            observedGeneration:
+              description: ObservedGeneration is the most recent generation observed
+                for the target. It corresponds to e.g. RunnerDeployment's generation,
+                which is updated on mutation by the API Server.
+              format: int64
+              type: integer
+          type: object
+      type: object
+  version: v1alpha1
+  versions:
+  - name: v1alpha1
+    served: true
+    storage: true
+status:
+  acceptedNames:
+    kind: ""
+    plural: ""
+  conditions: []
+  storedVersions: []

config/crd/kustomization.yaml

@@ -5,6 +5,7 @@ resources:
 - bases/actions.summerwind.dev_runners.yaml
 - bases/actions.summerwind.dev_runnerreplicasets.yaml
 - bases/actions.summerwind.dev_runnerdeployments.yaml
+- bases/actions.summerwind.dev_horizontalrunnerautoscalers.yaml
 # +kubebuilder:scaffold:crdkustomizeresource
 
 patchesStrategicMerge:

config/default/kustomization.yaml

@@ -50,7 +50,7 @@ vars:
   objref:
     kind: Certificate
     group: cert-manager.io
-    version: v1alpha2
+    version: v1
     name: serving-cert # this name should match the one in certificate.yaml
   fieldref:
     fieldpath: metadata.namespace
@@ -58,7 +58,7 @@ vars:
   objref:
     kind: Certificate
     group: cert-manager.io
-    version: v1alpha2
+    version: v1
     name: serving-cert # this name should match the one in certificate.yaml
 - name: SERVICE_NAMESPACE # namespace of the service
   objref:

config/rbac/role.yaml

@@ -6,6 +6,38 @@ metadata:
   creationTimestamp: null
   name: manager-role
 rules:
+- apiGroups:
+  - actions.summerwind.dev
+  resources:
+  - horizontalrunnerautoscalers
+  verbs:
+  - create
+  - delete
+  - 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:
@@ -18,6 +50,18 @@ rules:
   - patch
   - update
   - watch
+- apiGroups:
+  - actions.summerwind.dev
+  resources:
+  - runnerdeployments/finalizers
+  verbs:
+  - create
+  - delete
+  - get
+  - list
+  - patch
+  - update
+  - watch
 - apiGroups:
   - actions.summerwind.dev
   resources:
@@ -38,6 +82,18 @@ rules:
   - patch
   - update
   - watch
+- apiGroups:
+  - actions.summerwind.dev
+  resources:
+  - runnerreplicasets/finalizers
+  verbs:
+  - create
+  - delete
+  - get
+  - list
+  - patch
+  - update
+  - watch
 - apiGroups:
   - actions.summerwind.dev
   resources:
@@ -58,6 +114,18 @@ rules:
   - patch
   - update
   - watch
+- apiGroups:
+  - actions.summerwind.dev
+  resources:
+  - runners/finalizers
+  verbs:
+  - create
+  - delete
+  - get
+  - list
+  - patch
+  - update
+  - watch
 - apiGroups:
   - actions.summerwind.dev
   resources:
@@ -85,3 +153,15 @@ rules:
   - patch
   - update
   - watch
+- apiGroups:
+  - ""
+  resources:
+  - pods/finalizers
+  verbs:
+  - create
+  - delete
+  - get
+  - list
+  - patch
+  - update
+  - watch

controllers/autoscaling.go

@@ -0,0 +1,137 @@
+package controllers
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"strings"
+
+	"github.com/summerwind/actions-runner-controller/api/v1alpha1"
+)
+
+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)
+	} else if hra.Spec.MaxReplicas == nil {
+		return nil, fmt.Errorf("horizontalrunnerautoscaler %s/%s is missing maxReplicas", hra.Namespace, hra.Name)
+	}
+
+	var repos [][]string
+
+	repoID := rd.Spec.Template.Spec.Repository
+	if repoID == "" {
+		orgName := rd.Spec.Template.Spec.Organization
+		if orgName == "" {
+			return nil, fmt.Errorf("asserting runner deployment spec to detect bug: spec.template.organization should not be empty on this code path")
+		}
+
+		metrics := hra.Spec.Metrics
+
+		if len(metrics) == 0 {
+			return nil, fmt.Errorf("validating autoscaling metrics: one or more metrics is required")
+		} else if tpe := metrics[0].Type; tpe != v1alpha1.AutoscalingMetricTypeTotalNumberOfQueuedAndInProgressWorkflowRuns {
+			return nil, fmt.Errorf("validting autoscaling metrics: unsupported metric type %q: only supported value is %s", tpe, v1alpha1.AutoscalingMetricTypeTotalNumberOfQueuedAndInProgressWorkflowRuns)
+		} else if len(metrics[0].RepositoryNames) == 0 {
+			return nil, errors.New("validating autoscaling metrics: spec.autoscaling.metrics[].repositoryNames is required and must have one more more entries for organizational runner deployment")
+		}
+
+		for _, repoName := range metrics[0].RepositoryNames {
+			repos = append(repos, []string{orgName, repoName})
+		}
+	} else {
+		repo := strings.Split(repoID, "/")
+
+		repos = append(repos, repo)
+	}
+
+	var total, inProgress, queued, completed, unknown int
+	type callback func()
+	listWorkflowJobs := func(user string, repoName string, runID int64, fallback_cb callback) {
+		if runID == 0 {
+			fallback_cb()
+			return
+		}
+		jobs, _, err := r.GitHubClient.Actions.ListWorkflowJobs(context.TODO(), user, repoName, runID, nil)
+		if err != nil {
+			r.Log.Error(err, "Error listing workflow jobs")
+			fallback_cb()
+		} else if len(jobs.Jobs) == 0 {
+			fallback_cb()
+		} else {
+			for _, job := range jobs.Jobs {
+				switch job.GetStatus() {
+				case "completed":
+					// We add a case for `completed` so it is not counted in `unknown`.
+					// And we do not increment the counter for completed because
+					// that counter only refers to workflows. The reason for
+					// this is because we do not get a list of jobs for
+					// completed workflows in order to keep the number of API
+					// calls to a minimum.
+				case "in_progress":
+					inProgress++
+				case "queued":
+					queued++
+				default:
+					unknown++
+				}
+			}
+		}
+	}
+
+	for _, repo := range repos {
+		user, repoName := repo[0], repo[1]
+		list, _, err := r.GitHubClient.Actions.ListRepositoryWorkflowRuns(context.TODO(), user, repoName, nil)
+		if err != nil {
+			return nil, err
+		}
+
+		for _, run := range list.WorkflowRuns {
+			total++
+
+			// In May 2020, there are only 3 statuses.
+			// Follow the below links for more details:
+			// - https://developer.github.com/v3/actions/workflow-runs/#list-repository-workflow-runs
+			// - https://developer.github.com/v3/checks/runs/#create-a-check-run
+			switch run.GetStatus() {
+			case "completed":
+				completed++
+			case "in_progress":
+				listWorkflowJobs(user, repoName, run.GetID(), func() { inProgress++ })
+			case "queued":
+				listWorkflowJobs(user, repoName, run.GetID(), func() { queued++ })
+			default:
+				unknown++
+			}
+		}
+	}
+
+	minReplicas := *hra.Spec.MinReplicas
+	maxReplicas := *hra.Spec.MaxReplicas
+	necessaryReplicas := queued + inProgress
+
+	var desiredReplicas int
+
+	if necessaryReplicas < minReplicas {
+		desiredReplicas = minReplicas
+	} else if necessaryReplicas > maxReplicas {
+		desiredReplicas = maxReplicas
+	} else {
+		desiredReplicas = necessaryReplicas
+	}
+
+	rd.Status.Replicas = &desiredReplicas
+	replicas := desiredReplicas
+
+	r.Log.V(1).Info(
+		"Calculated desired replicas",
+		"computed_replicas_desired", desiredReplicas,
+		"spec_replicas_min", minReplicas,
+		"spec_replicas_max", maxReplicas,
+		"workflow_runs_completed", completed,
+		"workflow_runs_in_progress", inProgress,
+		"workflow_runs_queued", queued,
+		"workflow_runs_unknown", unknown,
+	)
+
+	return &replicas, nil
+}

controllers/autoscaling_test.go

@@ -0,0 +1,437 @@
+package controllers
+
+import (
+	"fmt"
+	"net/http/httptest"
+	"net/url"
+	"testing"
+
+	"github.com/summerwind/actions-runner-controller/api/v1alpha1"
+	"github.com/summerwind/actions-runner-controller/github"
+	"github.com/summerwind/actions-runner-controller/github/fake"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
+	"sigs.k8s.io/controller-runtime/pkg/log/zap"
+)
+
+func newGithubClient(server *httptest.Server) *github.Client {
+	c := github.Config{
+		Token: "token",
+	}
+	client, err := c.NewClient()
+	if err != nil {
+		panic(err)
+	}
+
+	baseURL, err := url.Parse(server.URL + "/")
+	if err != nil {
+		panic(err)
+	}
+	client.Client.BaseURL = baseURL
+
+	return client
+}
+
+func TestDetermineDesiredReplicas_RepositoryRunner(t *testing.T) {
+	intPtr := func(v int) *int {
+		return &v
+	}
+
+	metav1Now := metav1.Now()
+	testcases := []struct {
+		repo         string
+		org          string
+		fixed        *int
+		max          *int
+		min          *int
+		sReplicas    *int
+		sTime        *metav1.Time
+		workflowRuns string
+		workflowJobs map[int]string
+		want         int
+		err          string
+	}{
+		// Legacy functionality
+		// 3 demanded, max at 3
+		{
+			repo:         "test/valid",
+			min:          intPtr(2),
+			max:          intPtr(3),
+			workflowRuns: `{"total_count": 4, "workflow_runs":[{"status":"queued"}, {"status":"in_progress"}, {"status":"in_progress"}, {"status":"completed"}]}"`,
+			want:         3,
+		},
+		// 2 demanded, max at 3, currently 3, delay scaling down due to grace period
+		{
+			repo:         "test/valid",
+			min:          intPtr(2),
+			max:          intPtr(3),
+			sReplicas:    intPtr(3),
+			sTime:        &metav1Now,
+			workflowRuns: `{"total_count": 4, "workflow_runs":[{"status":"queued"}, {"status":"in_progress"}, {"status":"completed"}]}"`,
+			want:         3,
+		},
+		// 3 demanded, max at 2
+		{
+			repo:         "test/valid",
+			min:          intPtr(2),
+			max:          intPtr(2),
+			workflowRuns: `{"total_count": 4, "workflow_runs":[{"status":"queued"}, {"status":"in_progress"}, {"status":"in_progress"}, {"status":"completed"}]}"`,
+			want:         2,
+		},
+		// 2 demanded, min at 2
+		{
+			repo:         "test/valid",
+			min:          intPtr(2),
+			max:          intPtr(3),
+			workflowRuns: `{"total_count": 3, "workflow_runs":[{"status":"queued"}, {"status":"in_progress"}, {"status":"completed"}]}"`,
+			want:         2,
+		},
+		// 1 demanded, min at 2
+		{
+			repo:         "test/valid",
+			min:          intPtr(2),
+			max:          intPtr(3),
+			workflowRuns: `{"total_count": 2, "workflow_runs":[{"status":"queued"}, {"status":"completed"}]}"`,
+			want:         2,
+		},
+		// 1 demanded, min at 2
+		{
+			repo:         "test/valid",
+			min:          intPtr(2),
+			max:          intPtr(3),
+			workflowRuns: `{"total_count": 2, "workflow_runs":[{"status":"in_progress"}, {"status":"completed"}]}"`,
+			want:         2,
+		},
+		// 1 demanded, min at 1
+		{
+			repo:         "test/valid",
+			min:          intPtr(1),
+			max:          intPtr(3),
+			workflowRuns: `{"total_count": 2, "workflow_runs":[{"status":"queued"}, {"status":"completed"}]}"`,
+			want:         1,
+		},
+		// 1 demanded, min at 1
+		{
+			repo:         "test/valid",
+			min:          intPtr(1),
+			max:          intPtr(3),
+			workflowRuns: `{"total_count": 2, "workflow_runs":[{"status":"in_progress"}, {"status":"completed"}]}"`,
+			want:         1,
+		},
+		// fixed at 3
+		{
+			repo:         "test/valid",
+			min:          intPtr(1),
+			max:          intPtr(3),
+			fixed:        intPtr(3),
+			workflowRuns: `{"total_count": 4, "workflow_runs":[{"status":"in_progress"}, {"status":"in_progress"}, {"status":"in_progress"}, {"status":"completed"}]}"`,
+			want:         3,
+		},
+
+		// Job-level autoscaling
+		// 5 requested from 3 workflows
+		{
+			repo:         "test/valid",
+			min:          intPtr(2),
+			max:          intPtr(10),
+			workflowRuns: `{"total_count": 4, "workflow_runs":[{"id": 1, "status":"queued"}, {"id": 2, "status":"in_progress"}, {"id": 3, "status":"in_progress"}, {"status":"completed"}]}"`,
+			workflowJobs: map[int]string{
+				1: `{"jobs": [{"status":"queued"}, {"status":"queued"}]}`,
+				2: `{"jobs": [{"status": "in_progress"}, {"status":"completed"}]}`,
+				3: `{"jobs": [{"status": "in_progress"}, {"status":"queued"}]}`,
+			},
+			want: 5,
+		},
+	}
+
+	for i := range testcases {
+		tc := testcases[i]
+
+		log := zap.New(func(o *zap.Options) {
+			o.Development = true
+		})
+
+		scheme := runtime.NewScheme()
+		_ = clientgoscheme.AddToScheme(scheme)
+		_ = 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))
+			defer server.Close()
+			client := newGithubClient(server)
+
+			h := &HorizontalRunnerAutoscalerReconciler{
+				Log:          log,
+				GitHubClient: client,
+				Scheme:       scheme,
+			}
+
+			rd := v1alpha1.RunnerDeployment{
+				TypeMeta: metav1.TypeMeta{},
+				ObjectMeta: metav1.ObjectMeta{
+					Name: "testrd",
+				},
+				Spec: v1alpha1.RunnerDeploymentSpec{
+					Template: v1alpha1.RunnerTemplate{
+						Spec: v1alpha1.RunnerSpec{
+							Repository: tc.repo,
+						},
+					},
+					Replicas: tc.fixed,
+				},
+				Status: v1alpha1.RunnerDeploymentStatus{
+					Replicas: tc.sReplicas,
+				},
+			}
+
+			hra := v1alpha1.HorizontalRunnerAutoscaler{
+				Spec: v1alpha1.HorizontalRunnerAutoscalerSpec{
+					MaxReplicas: tc.max,
+					MinReplicas: tc.min,
+				},
+				Status: v1alpha1.HorizontalRunnerAutoscalerStatus{
+					DesiredReplicas:            tc.sReplicas,
+					LastSuccessfulScaleOutTime: tc.sTime,
+				},
+			}
+
+			got, err := h.computeReplicas(rd, hra)
+			if err != nil {
+				if tc.err == "" {
+					t.Fatalf("unexpected error: expected none, got %v", err)
+				} else if err.Error() != tc.err {
+					t.Fatalf("unexpected error: expected %v, got %v", tc.err, err)
+				}
+				return
+			}
+
+			if got == nil {
+				t.Fatalf("unexpected value of rs.Spec.Replicas: nil")
+			}
+
+			if *got != tc.want {
+				t.Errorf("%d: incorrect desired replicas: want %d, got %d", i, tc.want, *got)
+			}
+		})
+	}
+}
+
+func TestDetermineDesiredReplicas_OrganizationalRunner(t *testing.T) {
+	intPtr := func(v int) *int {
+		return &v
+	}
+
+	metav1Now := metav1.Now()
+	testcases := []struct {
+		repos        []string
+		org          string
+		fixed        *int
+		max          *int
+		min          *int
+		sReplicas    *int
+		sTime        *metav1.Time
+		workflowRuns string
+		workflowJobs map[int]string
+		want         int
+		err          string
+	}{
+		// 3 demanded, max at 3
+		{
+			org:          "test",
+			repos:        []string{"valid"},
+			min:          intPtr(2),
+			max:          intPtr(3),
+			workflowRuns: `{"total_count": 4, "workflow_runs":[{"status":"queued"}, {"status":"in_progress"}, {"status":"in_progress"}, {"status":"completed"}]}"`,
+			want:         3,
+		},
+		// 2 demanded, max at 3, currently 3, delay scaling down due to grace period
+		{
+			org:          "test",
+			repos:        []string{"valid"},
+			min:          intPtr(2),
+			max:          intPtr(3),
+			sReplicas:    intPtr(3),
+			sTime:        &metav1Now,
+			workflowRuns: `{"total_count": 4, "workflow_runs":[{"status":"queued"}, {"status":"in_progress"}, {"status":"completed"}]}"`,
+			want:         3,
+		},
+		// 3 demanded, max at 2
+		{
+			org:          "test",
+			repos:        []string{"valid"},
+			min:          intPtr(2),
+			max:          intPtr(2),
+			workflowRuns: `{"total_count": 4, "workflow_runs":[{"status":"queued"}, {"status":"in_progress"}, {"status":"in_progress"}, {"status":"completed"}]}"`,
+			want:         2,
+		},
+		// 2 demanded, min at 2
+		{
+			org:          "test",
+			repos:        []string{"valid"},
+			min:          intPtr(2),
+			max:          intPtr(3),
+			workflowRuns: `{"total_count": 3, "workflow_runs":[{"status":"queued"}, {"status":"in_progress"}, {"status":"completed"}]}"`,
+			want:         2,
+		},
+		// 1 demanded, min at 2
+		{
+			org:          "test",
+			repos:        []string{"valid"},
+			min:          intPtr(2),
+			max:          intPtr(3),
+			workflowRuns: `{"total_count": 2, "workflow_runs":[{"status":"queued"}, {"status":"completed"}]}"`,
+			want:         2,
+		},
+		// 1 demanded, min at 2
+		{
+			org:          "test",
+			repos:        []string{"valid"},
+			min:          intPtr(2),
+			max:          intPtr(3),
+			workflowRuns: `{"total_count": 2, "workflow_runs":[{"status":"in_progress"}, {"status":"completed"}]}"`,
+			want:         2,
+		},
+		// 1 demanded, min at 1
+		{
+			org:          "test",
+			repos:        []string{"valid"},
+			min:          intPtr(1),
+			max:          intPtr(3),
+			workflowRuns: `{"total_count": 2, "workflow_runs":[{"status":"queued"}, {"status":"completed"}]}"`,
+			want:         1,
+		},
+		// 1 demanded, min at 1
+		{
+			org:          "test",
+			repos:        []string{"valid"},
+			min:          intPtr(1),
+			max:          intPtr(3),
+			workflowRuns: `{"total_count": 2, "workflow_runs":[{"status":"in_progress"}, {"status":"completed"}]}"`,
+			want:         1,
+		},
+		// fixed at 3
+		{
+			org:          "test",
+			repos:        []string{"valid"},
+			fixed:        intPtr(1),
+			min:          intPtr(1),
+			max:          intPtr(3),
+			workflowRuns: `{"total_count": 2, "workflow_runs":[{"status":"in_progress"}, {"status":"in_progress"}, {"status":"in_progress"}, {"status":"completed"}]}"`,
+			want:         3,
+		},
+		// org runner, fixed at 3
+		{
+			org:          "test",
+			repos:        []string{"valid"},
+			fixed:        intPtr(1),
+			min:          intPtr(1),
+			max:          intPtr(3),
+			workflowRuns: `{"total_count": 2, "workflow_runs":[{"status":"in_progress"}, {"status":"in_progress"}, {"status":"in_progress"}, {"status":"completed"}]}"`,
+			want:         3,
+		},
+		// org runner, 1 demanded, min at 1, no repos
+		{
+			org:          "test",
+			min:          intPtr(1),
+			max:          intPtr(3),
+			workflowRuns: `{"total_count": 2, "workflow_runs":[{"status":"in_progress"}, {"status":"completed"}]}"`,
+			err:          "validating autoscaling metrics: spec.autoscaling.metrics[].repositoryNames is required and must have one more more entries for organizational runner deployment",
+		},
+
+		// Job-level autoscaling
+		// 5 requested from 3 workflows
+		{
+			org:          "test",
+			repos:        []string{"valid"},
+			min:          intPtr(2),
+			max:          intPtr(10),
+			workflowRuns: `{"total_count": 4, "workflow_runs":[{"id": 1, "status":"queued"}, {"id": 2, "status":"in_progress"}, {"id": 3, "status":"in_progress"}, {"status":"completed"}]}"`,
+			workflowJobs: map[int]string{
+				1: `{"jobs": [{"status":"queued"}, {"status":"queued"}]}`,
+				2: `{"jobs": [{"status": "in_progress"}, {"status":"completed"}]}`,
+				3: `{"jobs": [{"status": "in_progress"}, {"status":"queued"}]}`,
+			},
+			want: 5,
+		},
+	}
+
+	for i := range testcases {
+		tc := testcases[i]
+
+		log := zap.New(func(o *zap.Options) {
+			o.Development = true
+		})
+
+		scheme := runtime.NewScheme()
+		_ = clientgoscheme.AddToScheme(scheme)
+		_ = 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))
+			defer server.Close()
+			client := newGithubClient(server)
+
+			h := &HorizontalRunnerAutoscalerReconciler{
+				Log:          log,
+				Scheme:       scheme,
+				GitHubClient: client,
+			}
+
+			rd := v1alpha1.RunnerDeployment{
+				ObjectMeta: metav1.ObjectMeta{
+					Name: "testrd",
+				},
+				Spec: v1alpha1.RunnerDeploymentSpec{
+					Template: v1alpha1.RunnerTemplate{
+						Spec: v1alpha1.RunnerSpec{
+							Organization: tc.org,
+						},
+					},
+					Replicas: tc.fixed,
+				},
+				Status: v1alpha1.RunnerDeploymentStatus{
+					Replicas: tc.sReplicas,
+				},
+			}
+
+			hra := v1alpha1.HorizontalRunnerAutoscaler{
+				Spec: v1alpha1.HorizontalRunnerAutoscalerSpec{
+					ScaleTargetRef: v1alpha1.ScaleTargetRef{
+						Name: "testrd",
+					},
+					MaxReplicas: tc.max,
+					MinReplicas: tc.min,
+					Metrics: []v1alpha1.MetricSpec{
+						{
+							Type:            v1alpha1.AutoscalingMetricTypeTotalNumberOfQueuedAndInProgressWorkflowRuns,
+							RepositoryNames: tc.repos,
+						},
+					},
+				},
+				Status: v1alpha1.HorizontalRunnerAutoscalerStatus{
+					DesiredReplicas:            tc.sReplicas,
+					LastSuccessfulScaleOutTime: tc.sTime,
+				},
+			}
+
+			got, err := h.computeReplicas(rd, hra)
+			if err != nil {
+				if tc.err == "" {
+					t.Fatalf("unexpected error: expected none, got %v", err)
+				} else if err.Error() != tc.err {
+					t.Fatalf("unexpected error: expected %v, got %v", tc.err, err)
+				}
+				return
+			}
+
+			if got == nil {
+				t.Fatalf("unexpected value of rs.Spec.Replicas: nil, wanted %v", tc.want)
+			}
+
+			if *got != tc.want {
+				t.Errorf("%d: incorrect desired replicas: want %d, got %d", i, tc.want, *got)
+			}
+		})
+	}
+}

controllers/horizontalrunnerautoscaler_controller.go

@@ -0,0 +1,168 @@
+/*
+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"
+	"time"
+
+	"github.com/summerwind/actions-runner-controller/github"
+	"k8s.io/apimachinery/pkg/types"
+
+	"github.com/go-logr/logr"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/client-go/tools/record"
+	ctrl "sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+
+	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+
+	"github.com/summerwind/actions-runner-controller/api/v1alpha1"
+)
+
+const (
+	DefaultScaleDownDelay = 10 * time.Minute
+)
+
+// HorizontalRunnerAutoscalerReconciler reconciles a HorizontalRunnerAutoscaler object
+type HorizontalRunnerAutoscalerReconciler struct {
+	client.Client
+	GitHubClient *github.Client
+	Log          logr.Logger
+	Recorder     record.EventRecorder
+	Scheme       *runtime.Scheme
+}
+
+// +kubebuilder:rbac:groups=actions.summerwind.dev,resources=runnerdeployments,verbs=get;list;watch;update;patch
+// +kubebuilder:rbac:groups=actions.summerwind.dev,resources=horizontalrunnerautoscalers,verbs=get;list;watch;create;update;patch;delete
+// +kubebuilder:rbac:groups=actions.summerwind.dev,resources=horizontalrunnerautoscalers/finalizers,verbs=get;list;watch;create;update;patch;delete
+// +kubebuilder:rbac:groups=actions.summerwind.dev,resources=horizontalrunnerautoscalers/status,verbs=get;update;patch
+// +kubebuilder:rbac:groups=core,resources=events,verbs=create;patch
+
+func (r *HorizontalRunnerAutoscalerReconciler) Reconcile(req ctrl.Request) (ctrl.Result, error) {
+	ctx := context.Background()
+	log := r.Log.WithValues("horizontalrunnerautoscaler", req.NamespacedName)
+
+	var hra v1alpha1.HorizontalRunnerAutoscaler
+	if err := r.Get(ctx, req.NamespacedName, &hra); err != nil {
+		return ctrl.Result{}, client.IgnoreNotFound(err)
+	}
+
+	if !hra.ObjectMeta.DeletionTimestamp.IsZero() {
+		return ctrl.Result{}, nil
+	}
+
+	var rd v1alpha1.RunnerDeployment
+	if err := r.Get(ctx, types.NamespacedName{
+		Namespace: req.Namespace,
+		Name:      hra.Spec.ScaleTargetRef.Name,
+	}, &rd); err != nil {
+		return ctrl.Result{}, client.IgnoreNotFound(err)
+	}
+
+	if !rd.ObjectMeta.DeletionTimestamp.IsZero() {
+		return ctrl.Result{}, nil
+	}
+
+	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
+
+	currentDesiredReplicas := getIntOrDefault(rd.Spec.Replicas, defaultReplicas)
+	newDesiredReplicas := getIntOrDefault(replicas, defaultReplicas)
+
+	// Please add more conditions that we can in-place update the newest runnerreplicaset without disruption
+	if currentDesiredReplicas != newDesiredReplicas {
+		copy := rd.DeepCopy()
+		copy.Spec.Replicas = &newDesiredReplicas
+
+		if err := r.Client.Update(ctx, copy); err != nil {
+			log.Error(err, "Failed to update runnerderployment resource")
+
+			return ctrl.Result{}, err
+		}
+
+		return ctrl.Result{}, err
+	}
+
+	if hra.Status.DesiredReplicas == nil || *hra.Status.DesiredReplicas != *replicas {
+		updated := hra.DeepCopy()
+
+		if (hra.Status.DesiredReplicas == nil && *replicas > 1) ||
+			(hra.Status.DesiredReplicas != nil && *replicas > *hra.Status.DesiredReplicas) {
+
+			updated.Status.LastSuccessfulScaleOutTime = &metav1.Time{Time: time.Now()}
+		}
+
+		updated.Status.DesiredReplicas = replicas
+
+		if err := r.Status().Update(ctx, updated); err != nil {
+			log.Error(err, "Failed to update horizontalrunnerautoscaler status")
+
+			return ctrl.Result{}, err
+		}
+	}
+
+	return ctrl.Result{}, nil
+}
+
+func (r *HorizontalRunnerAutoscalerReconciler) SetupWithManager(mgr ctrl.Manager) error {
+	r.Recorder = mgr.GetEventRecorderFor("horizontalrunnerautoscaler-controller")
+
+	return ctrl.NewControllerManagedBy(mgr).
+		For(&v1alpha1.HorizontalRunnerAutoscaler{}).
+		Complete(r)
+}
+
+func (r *HorizontalRunnerAutoscalerReconciler) computeReplicas(rd v1alpha1.RunnerDeployment, hra v1alpha1.HorizontalRunnerAutoscaler) (*int, error) {
+	var computedReplicas *int
+
+	replicas, err := r.determineDesiredReplicas(rd, hra)
+	if err != nil {
+		return nil, err
+	}
+
+	var scaleDownDelay time.Duration
+
+	if hra.Spec.ScaleDownDelaySecondsAfterScaleUp != nil {
+		scaleDownDelay = time.Duration(*hra.Spec.ScaleDownDelaySecondsAfterScaleUp) * time.Second
+	} else {
+		scaleDownDelay = DefaultScaleDownDelay
+	}
+
+	now := time.Now()
+
+	if hra.Status.DesiredReplicas == nil ||
+		*hra.Status.DesiredReplicas < *replicas ||
+		hra.Status.LastSuccessfulScaleOutTime == nil ||
+		hra.Status.LastSuccessfulScaleOutTime.Add(scaleDownDelay).Before(now) {
+
+		computedReplicas = replicas
+	} else {
+		computedReplicas = hra.Status.DesiredReplicas
+	}
+
+	return computedReplicas, nil
+}

controllers/integration_test.go

@@ -0,0 +1,315 @@
+package controllers
+
+import (
+	"context"
+	"time"
+
+	"github.com/summerwind/actions-runner-controller/github/fake"
+
+	corev1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/types"
+	"k8s.io/client-go/kubernetes/scheme"
+	ctrl "sigs.k8s.io/controller-runtime"
+	logf "sigs.k8s.io/controller-runtime/pkg/log"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+
+	actionsv1alpha1 "github.com/summerwind/actions-runner-controller/api/v1alpha1"
+)
+
+type testEnvironment struct {
+	Namespace *corev1.Namespace
+	Responses *fake.FixedResponses
+}
+
+var (
+	workflowRunsFor3Replicas = `{"total_count": 5, "workflow_runs":[{"status":"queued"}, {"status":"queued"}, {"status":"in_progress"}, {"status":"in_progress"}, {"status":"completed"}]}"`
+	workflowRunsFor1Replicas = `{"total_count": 6, "workflow_runs":[{"status":"queued"}, {"status":"completed"}, {"status":"completed"}, {"status":"completed"}, {"status":"completed"}]}"`
+)
+
+// SetupIntegrationTest will set up a testing environment.
+// This includes:
+// * creating a Namespace to be used during the test
+// * starting all the reconcilers
+// * stopping all the reconcilers after the test ends
+// Call this function at the start of each of your tests.
+func SetupIntegrationTest(ctx context.Context) *testEnvironment {
+	var stopCh chan struct{}
+	ns := &corev1.Namespace{}
+
+	responses := &fake.FixedResponses{}
+	responses.ListRepositoryWorkflowRuns = &fake.Handler{
+		Status: 200,
+		Body:   workflowRunsFor3Replicas,
+	}
+	fakeGithubServer := fake.NewServer(fake.WithFixedResponses(responses))
+
+	BeforeEach(func() {
+		stopCh = make(chan struct{})
+		*ns = corev1.Namespace{
+			ObjectMeta: metav1.ObjectMeta{Name: "testns-" + randStringRunes(5)},
+		}
+
+		err := k8sClient.Create(ctx, ns)
+		Expect(err).NotTo(HaveOccurred(), "failed to create test namespace")
+
+		mgr, err := ctrl.NewManager(cfg, ctrl.Options{})
+		Expect(err).NotTo(HaveOccurred(), "failed to create manager")
+
+		runnersList = fake.NewRunnersList()
+		server = runnersList.GetServer()
+		ghClient := newGithubClient(server)
+
+		replicasetController := &RunnerReplicaSetReconciler{
+			Client:       mgr.GetClient(),
+			Scheme:       scheme.Scheme,
+			Log:          logf.Log,
+			Recorder:     mgr.GetEventRecorderFor("runnerreplicaset-controller"),
+			GitHubClient: ghClient,
+		}
+		err = replicasetController.SetupWithManager(mgr)
+		Expect(err).NotTo(HaveOccurred(), "failed to setup controller")
+
+		deploymentsController := &RunnerDeploymentReconciler{
+			Client:   mgr.GetClient(),
+			Scheme:   scheme.Scheme,
+			Log:      logf.Log,
+			Recorder: mgr.GetEventRecorderFor("runnerdeployment-controller"),
+		}
+		err = deploymentsController.SetupWithManager(mgr)
+		Expect(err).NotTo(HaveOccurred(), "failed to setup controller")
+
+		client := newGithubClient(fakeGithubServer)
+
+		autoscalerController := &HorizontalRunnerAutoscalerReconciler{
+			Client:       mgr.GetClient(),
+			Scheme:       scheme.Scheme,
+			Log:          logf.Log,
+			GitHubClient: client,
+			Recorder:     mgr.GetEventRecorderFor("horizontalrunnerautoscaler-controller"),
+		}
+		err = autoscalerController.SetupWithManager(mgr)
+		Expect(err).NotTo(HaveOccurred(), "failed to setup controller")
+
+		go func() {
+			defer GinkgoRecover()
+
+			err := mgr.Start(stopCh)
+			Expect(err).NotTo(HaveOccurred(), "failed to start manager")
+		}()
+	})
+
+	AfterEach(func() {
+		close(stopCh)
+
+		fakeGithubServer.Close()
+
+		err := k8sClient.Delete(ctx, ns)
+		Expect(err).NotTo(HaveOccurred(), "failed to delete test namespace")
+	})
+
+	return &testEnvironment{Namespace: ns, Responses: responses}
+}
+
+var _ = Context("Inside of a new namespace", func() {
+	ctx := context.TODO()
+	env := SetupIntegrationTest(ctx)
+	ns := env.Namespace
+	responses := env.Responses
+
+	Describe("when no existing resources exist", func() {
+
+		It("should create and scale runners", func() {
+			name := "example-runnerdeploy"
+
+			{
+				rs := &actionsv1alpha1.RunnerDeployment{
+					ObjectMeta: metav1.ObjectMeta{
+						Name:      name,
+						Namespace: ns.Name,
+					},
+					Spec: actionsv1alpha1.RunnerDeploymentSpec{
+						Replicas: intPtr(1),
+						Template: actionsv1alpha1.RunnerTemplate{
+							Spec: actionsv1alpha1.RunnerSpec{
+								Repository: "test/valid",
+								Image:      "bar",
+								Group:      "baz",
+								Env: []corev1.EnvVar{
+									{Name: "FOO", Value: "FOOVALUE"},
+								},
+							},
+						},
+					},
+				}
+
+				err := k8sClient.Create(ctx, rs)
+
+				Expect(err).NotTo(HaveOccurred(), "failed to create test RunnerDeployment resource")
+
+				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))
+
+				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(1))
+			}
+
+			{
+				// We wrap the update in the Eventually block to avoid the below error that occurs due to concurrent modification
+				// made by the controller to update .Status.AvailableReplicas and .Status.ReadyReplicas
+				//   Operation cannot be fulfilled on runnersets.actions.summerwind.dev "example-runnerset": the object has been modified; please apply your changes to the latest version and try again
+				Eventually(func() error {
+					var rd actionsv1alpha1.RunnerDeployment
+
+					err := k8sClient.Get(ctx, types.NamespacedName{Namespace: ns.Name, Name: name}, &rd)
+
+					Expect(err).NotTo(HaveOccurred(), "failed to get test RunnerDeployment resource")
+
+					rd.Spec.Replicas = intPtr(2)
+
+					return k8sClient.Update(ctx, &rd)
+				},
+					time.Second*1, time.Millisecond*500).Should(BeNil())
+
+				runnerSets := actionsv1alpha1.RunnerReplicaSetList{Items: []actionsv1alpha1.RunnerReplicaSet{}}
+
+				Eventually(
+					func() int {
+						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))
+
+				Eventually(
+					func() int {
+						err := k8sClient.List(ctx, &runnerSets, client.InNamespace(ns.Name))
+						if err != nil {
+							logf.Log.Error(err, "list runner sets")
+						}
+
+						return *runnerSets.Items[0].Spec.Replicas
+					},
+					time.Second*5, time.Millisecond*500).Should(BeEquivalentTo(2))
+			}
+
+			// Scale-up to 3 replicas
+			{
+				hra := &actionsv1alpha1.HorizontalRunnerAutoscaler{
+					ObjectMeta: metav1.ObjectMeta{
+						Name:      name,
+						Namespace: ns.Name,
+					},
+					Spec: actionsv1alpha1.HorizontalRunnerAutoscalerSpec{
+						ScaleTargetRef: actionsv1alpha1.ScaleTargetRef{
+							Name: name,
+						},
+						MinReplicas:                       intPtr(1),
+						MaxReplicas:                       intPtr(3),
+						ScaleDownDelaySecondsAfterScaleUp: nil,
+						Metrics:                           nil,
+					},
+				}
+
+				err := k8sClient.Create(ctx, hra)
+
+				Expect(err).NotTo(HaveOccurred(), "failed to create test HorizontalRunnerAutoscaler resource")
+
+				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))
+
+				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(3))
+			}
+
+			// Scale-down to 1 replica
+			{
+				responses.ListRepositoryWorkflowRuns.Body = workflowRunsFor1Replicas
+
+				var hra actionsv1alpha1.HorizontalRunnerAutoscaler
+
+				err := k8sClient.Get(ctx, types.NamespacedName{Namespace: ns.Name, Name: name}, &hra)
+
+				Expect(err).NotTo(HaveOccurred(), "failed to get test HorizontalRunnerAutoscaler resource")
+
+				hra.Annotations = map[string]string{
+					"force-update": "1",
+				}
+
+				err = k8sClient.Update(ctx, &hra)
+
+				Expect(err).NotTo(HaveOccurred(), "failed to get test HorizontalRunnerAutoscaler resource")
+
+				Eventually(
+					func() int {
+						var runnerSets actionsv1alpha1.RunnerReplicaSetList
+
+						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(1))
+			}
+		})
+	})
+})

controllers/runner_controller.go

@@ -53,8 +53,10 @@ type RunnerReconciler struct {
 }
 
 // +kubebuilder:rbac:groups=actions.summerwind.dev,resources=runners,verbs=get;list;watch;create;update;patch;delete
+// +kubebuilder:rbac:groups=actions.summerwind.dev,resources=runners/finalizers,verbs=get;list;watch;create;update;patch;delete
 // +kubebuilder:rbac:groups=actions.summerwind.dev,resources=runners/status,verbs=get;update;patch
 // +kubebuilder:rbac:groups=core,resources=pods,verbs=get;list;watch;create;update;patch;delete
+// +kubebuilder:rbac:groups=core,resources=pods/finalizers,verbs=get;list;watch;create;update;patch;delete
 // +kubebuilder:rbac:groups=core,resources=events,verbs=create;patch
 
 func (r *RunnerReconciler) Reconcile(req ctrl.Request) (ctrl.Result, error) {
@@ -118,39 +120,18 @@ func (r *RunnerReconciler) Reconcile(req ctrl.Request) (ctrl.Result, error) {
 		return ctrl.Result{}, nil
 	}
 
-	if !runner.IsRegisterable() {
-		rt, err := r.GitHubClient.GetRegistrationToken(ctx, 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")
-			return ctrl.Result{}, err
-		}
-
-		updated := runner.DeepCopy()
-		updated.Status.Registration = v1alpha1.RunnerStatusRegistration{
-			Organization: runner.Spec.Organization,
-			Repository:   runner.Spec.Repository,
-			Labels:       runner.Spec.Labels,
-			Token:        rt.GetToken(),
-			ExpiresAt:    metav1.NewTime(rt.GetExpiresAt().Time),
-		}
-
-		if err := r.Status().Update(ctx, updated); err != nil {
-			log.Error(err, "Failed to update runner status")
-			return ctrl.Result{}, err
-		}
-
-		r.Recorder.Event(&runner, corev1.EventTypeNormal, "RegistrationTokenUpdated", "Successfully update registration token")
-		log.Info("Updated registration token", "repository", runner.Spec.Repository)
-		return ctrl.Result{}, nil
-	}
-
 	var pod corev1.Pod
 	if err := r.Get(ctx, req.NamespacedName, &pod); err != nil {
 		if !errors.IsNotFound(err) {
 			return ctrl.Result{}, err
 		}
 
+		if updated, err := r.updateRegistrationToken(ctx, runner); err != nil {
+			return ctrl.Result{}, err
+		} else if updated {
+			return ctrl.Result{Requeue: true}, nil
+		}
+
 		newPod, err := r.newPod(runner)
 		if err != nil {
 			log.Error(err, "Could not create pod")
@@ -165,7 +146,11 @@ func (r *RunnerReconciler) Reconcile(req ctrl.Request) (ctrl.Result, error) {
 		r.Recorder.Event(&runner, corev1.EventTypeNormal, "PodCreated", fmt.Sprintf("Created pod '%s'", newPod.Name))
 		log.Info("Created runner pod", "repository", runner.Spec.Repository)
 	} else {
-		if runner.Status.Phase != string(pod.Status.Phase) {
+		// If pod has ended up succeeded we need to restart it
+		// Happens e.g. when dind is in runner and run completes
+		restart := pod.Status.Phase == corev1.PodSucceeded
+
+		if !restart && runner.Status.Phase != string(pod.Status.Phase) {
 			updated := runner.DeepCopy()
 			updated.Status.Phase = string(pod.Status.Phase)
 			updated.Status.Reason = pod.Status.Reason
@@ -183,8 +168,6 @@ func (r *RunnerReconciler) Reconcile(req ctrl.Request) (ctrl.Result, error) {
 			return ctrl.Result{}, err
 		}
 
-		restart := false
-
 		if pod.Status.Phase == corev1.PodRunning {
 			for _, status := range pod.Status.ContainerStatuses {
 				if status.Name != containerName {
@@ -197,18 +180,28 @@ func (r *RunnerReconciler) Reconcile(req ctrl.Request) (ctrl.Result, error) {
 			}
 		}
 
+		if updated, err := r.updateRegistrationToken(ctx, runner); err != nil {
+			return ctrl.Result{}, err
+		} else if updated {
+			return ctrl.Result{Requeue: true}, nil
+		}
+
 		newPod, err := r.newPod(runner)
 		if err != nil {
 			log.Error(err, "Could not create pod")
 			return ctrl.Result{}, err
 		}
 
-		if pod.Spec.Containers[0].Image != newPod.Spec.Containers[0].Image {
-			restart = true
-		}
-		if !reflect.DeepEqual(pod.Spec.Containers[0].Env, newPod.Spec.Containers[0].Env) {
+		runnerBusy, err := r.isRunnerBusy(ctx, 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
+		}
+
+		if !runnerBusy && (!reflect.DeepEqual(pod.Spec.Containers[0].Env, newPod.Spec.Containers[0].Env) || pod.Spec.Containers[0].Image != newPod.Spec.Containers[0].Image) {
 			restart = true
 		}
+
 		if !restart {
 			return ctrl.Result{}, err
 		}
@@ -225,6 +218,21 @@ 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)
 	if err != nil {
@@ -234,6 +242,9 @@ func (r *RunnerReconciler) unregisterRunner(ctx context.Context, org, repo, name
 	id := int64(0)
 	for _, runner := range runners {
 		if runner.GetName() == name {
+			if runner.GetBusy() {
+				return false, fmt.Errorf("runner is busy")
+			}
 			id = runner.GetID()
 			break
 		}
@@ -250,10 +261,44 @@ func (r *RunnerReconciler) unregisterRunner(ctx context.Context, org, repo, name
 	return true, nil
 }
 
+func (r *RunnerReconciler) updateRegistrationToken(ctx context.Context, runner v1alpha1.Runner) (bool, error) {
+	if runner.IsRegisterable() {
+		return false, nil
+	}
+
+	log := r.Log.WithValues("runner", runner.Name)
+
+	rt, err := r.GitHubClient.GetRegistrationToken(ctx, 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")
+		return false, err
+	}
+
+	updated := runner.DeepCopy()
+	updated.Status.Registration = v1alpha1.RunnerStatusRegistration{
+		Organization: runner.Spec.Organization,
+		Repository:   runner.Spec.Repository,
+		Labels:       runner.Spec.Labels,
+		Token:        rt.GetToken(),
+		ExpiresAt:    metav1.NewTime(rt.GetExpiresAt().Time),
+	}
+
+	if err := r.Status().Update(ctx, updated); err != nil {
+		log.Error(err, "Failed to update runner status")
+		return false, err
+	}
+
+	r.Recorder.Event(&runner, corev1.EventTypeNormal, "RegistrationTokenUpdated", "Successfully update registration token")
+	log.Info("Updated registration token", "repository", runner.Spec.Repository)
+
+	return true, nil
+}
+
 func (r *RunnerReconciler) newPod(runner v1alpha1.Runner) (corev1.Pod, error) {
 	var (
 		privileged      bool = true
-		group      int64 = 0
+		dockerdInRunner bool = runner.Spec.DockerdWithinRunnerContainer != nil && *runner.Spec.DockerdWithinRunnerContainer
 	)
 
 	runnerImage := runner.Spec.Image
@@ -261,6 +306,11 @@ func (r *RunnerReconciler) newPod(runner v1alpha1.Runner) (corev1.Pod, error) {
 		runnerImage = r.RunnerImage
 	}
 
+	runnerImagePullPolicy := runner.Spec.ImagePullPolicy
+	if runnerImagePullPolicy == "" {
+		runnerImagePullPolicy = corev1.PullAlways
+	}
+
 	env := []corev1.EnvVar{
 		{
 			Name:  "RUNNER_NAME",
@@ -278,10 +328,22 @@ func (r *RunnerReconciler) newPod(runner v1alpha1.Runner) (corev1.Pod, error) {
 			Name:  "RUNNER_LABELS",
 			Value: strings.Join(runner.Spec.Labels, ","),
 		},
+		{
+			Name:  "RUNNER_GROUP",
+			Value: runner.Spec.Group,
+		},
 		{
 			Name:  "RUNNER_TOKEN",
 			Value: runner.Status.Registration.Token,
 		},
+		{
+			Name:  "DOCKERD_IN_RUNNER",
+			Value: fmt.Sprintf("%v", dockerdInRunner),
+		},
+		{
+			Name:  "GITHUB_URL",
+			Value: r.GitHubClient.GithubBaseURL,
+		},
 	}
 
 	env = append(env, runner.Spec.Env...)
@@ -298,10 +360,35 @@ func (r *RunnerReconciler) newPod(runner v1alpha1.Runner) (corev1.Pod, error) {
 				{
 					Name:            containerName,
 					Image:           runnerImage,
-					ImagePullPolicy: "Always",
+					ImagePullPolicy: runnerImagePullPolicy,
 					Env:             env,
 					EnvFrom:         runner.Spec.EnvFrom,
-					VolumeMounts: []corev1.VolumeMount{
+					SecurityContext: &corev1.SecurityContext{
+						// Runner need to run privileged if it contains DinD
+						Privileged: runner.Spec.DockerdWithinRunnerContainer,
+					},
+					Resources: runner.Spec.Resources,
+				},
+			},
+		},
+	}
+
+	if !dockerdInRunner {
+		pod.Spec.Volumes = []corev1.Volume{
+			{
+				Name: "work",
+				VolumeSource: corev1.VolumeSource{
+					EmptyDir: &corev1.EmptyDirVolumeSource{},
+				},
+			},
+			{
+				Name: "docker",
+				VolumeSource: corev1.VolumeSource{
+					EmptyDir: &corev1.EmptyDirVolumeSource{},
+				},
+			},
+		}
+		pod.Spec.Containers[0].VolumeMounts = []corev1.VolumeMount{
 			{
 				Name:      "work",
 				MountPath: "/runner/_work",
@@ -310,13 +397,8 @@ func (r *RunnerReconciler) newPod(runner v1alpha1.Runner) (corev1.Pod, error) {
 				Name:      "docker",
 				MountPath: "/var/run",
 			},
-					},
-					SecurityContext: &corev1.SecurityContext{
-						RunAsGroup: &group,
-					},
-					Resources: runner.Spec.Resources,
-				},
-				{
+		}
+		pod.Spec.Containers = append(pod.Spec.Containers, corev1.Container{
 			Name:  "docker",
 			Image: r.DockerImage,
 			VolumeMounts: []corev1.VolumeMount{
@@ -332,27 +414,17 @@ func (r *RunnerReconciler) newPod(runner v1alpha1.Runner) (corev1.Pod, error) {
 			SecurityContext: &corev1.SecurityContext{
 				Privileged: &privileged,
 			},
-				},
-			},
-			Volumes: []corev1.Volume{
-				{
-					Name: "work",
-					VolumeSource: corev1.VolumeSource{
-						EmptyDir: &corev1.EmptyDirVolumeSource{},
-					},
-				},
-				{
-					Name: "docker",
-					VolumeSource: corev1.VolumeSource{
-						EmptyDir: &corev1.EmptyDirVolumeSource{},
-					},
-				},
-			},
-		},
+		})
+
 	}
 
 	if len(runner.Spec.Containers) != 0 {
 		pod.Spec.Containers = runner.Spec.Containers
+		for i := 0; i < len(pod.Spec.Containers); i++ {
+			if pod.Spec.Containers[i].Name == containerName {
+				pod.Spec.Containers[i].Env = append(pod.Spec.Containers[i].Env, env...)
+			}
+		}
 	}
 
 	if len(runner.Spec.VolumeMounts) != 0 {

controllers/runnerdeployment_controller.go

@@ -20,10 +20,11 @@ import (
 	"context"
 	"fmt"
 	"hash/fnv"
-	"k8s.io/apimachinery/pkg/types"
 	"sort"
 	"time"
 
+	"k8s.io/apimachinery/pkg/types"
+
 	"github.com/davecgh/go-spew/spew"
 	"github.com/go-logr/logr"
 	"k8s.io/apimachinery/pkg/runtime"
@@ -53,6 +54,7 @@ type RunnerDeploymentReconciler struct {
 }
 
 // +kubebuilder:rbac:groups=actions.summerwind.dev,resources=runnerdeployments,verbs=get;list;watch;create;update;patch;delete
+// +kubebuilder:rbac:groups=actions.summerwind.dev,resources=runnerdeployments/finalizers,verbs=get;list;watch;create;update;patch;delete
 // +kubebuilder:rbac:groups=actions.summerwind.dev,resources=runnerdeployments/status,verbs=get;update;patch
 // +kubebuilder:rbac:groups=actions.summerwind.dev,resources=runnerreplicasets,verbs=get;list;watch;create;update;patch;delete
 // +kubebuilder:rbac:groups=actions.summerwind.dev,resources=runnerreplicasets/status,verbs=get;update;patch
@@ -96,13 +98,15 @@ func (r *RunnerDeploymentReconciler) Reconcile(req ctrl.Request) (ctrl.Result, e
 
 	desiredRS, err := r.newRunnerReplicaSet(rd)
 	if err != nil {
+		r.Recorder.Event(&rd, corev1.EventTypeNormal, "RunnerAutoscalingFailure", err.Error())
+
 		log.Error(err, "Could not create runnerreplicaset")
 
 		return ctrl.Result{}, err
 	}
 
 	if newestSet == nil {
-		if err := r.Client.Create(ctx, &desiredRS); err != nil {
+		if err := r.Client.Create(ctx, desiredRS); err != nil {
 			log.Error(err, "Failed to create runnerreplicaset resource")
 
 			return ctrl.Result{}, err
@@ -118,7 +122,7 @@ func (r *RunnerDeploymentReconciler) Reconcile(req ctrl.Request) (ctrl.Result, e
 		return ctrl.Result{}, nil
 	}
 
-	desiredTemplateHash, ok := getTemplateHash(&desiredRS)
+	desiredTemplateHash, ok := getTemplateHash(desiredRS)
 	if !ok {
 		log.Info("Failed to get template hash of desired runnerreplicaset resource. It must be in an invalid state. Please manually delete the runnerreplicaset so that it is recreated")
 
@@ -126,7 +130,7 @@ func (r *RunnerDeploymentReconciler) Reconcile(req ctrl.Request) (ctrl.Result, e
 	}
 
 	if newestTemplateHash != desiredTemplateHash {
-		if err := r.Client.Create(ctx, &desiredRS); err != nil {
+		if err := r.Client.Create(ctx, desiredRS); err != nil {
 			log.Error(err, "Failed to create runnerreplicaset resource")
 
 			return ctrl.Result{}, err
@@ -184,6 +188,17 @@ func (r *RunnerDeploymentReconciler) Reconcile(req ctrl.Request) (ctrl.Result, e
 		}
 	}
 
+	if rd.Spec.Replicas == nil && desiredRS.Spec.Replicas != nil {
+		updated := rd.DeepCopy()
+		updated.Status.Replicas = desiredRS.Spec.Replicas
+
+		if err := r.Status().Update(ctx, updated); err != nil {
+			log.Error(err, "Failed to update runnerdeployment status")
+
+			return ctrl.Result{}, err
+		}
+	}
+
 	return ctrl.Result{}, nil
 }
 
@@ -241,7 +256,7 @@ func CloneAndAddLabel(labels map[string]string, labelKey, labelValue string) map
 	return newLabels
 }
 
-func (r *RunnerDeploymentReconciler) newRunnerReplicaSet(rd v1alpha1.RunnerDeployment) (v1alpha1.RunnerReplicaSet, error) {
+func (r *RunnerDeploymentReconciler) newRunnerReplicaSet(rd v1alpha1.RunnerDeployment) (*v1alpha1.RunnerReplicaSet, error) {
 	newRSTemplate := *rd.Spec.Template.DeepCopy()
 	templateHash := ComputeHash(&newRSTemplate)
 	// Add template hash label to selector.
@@ -263,10 +278,10 @@ func (r *RunnerDeploymentReconciler) newRunnerReplicaSet(rd v1alpha1.RunnerDeplo
 	}
 
 	if err := ctrl.SetControllerReference(&rd, &rs, r.Scheme); err != nil {
-		return rs, err
+		return &rs, err
 	}
 
-	return rs, nil
+	return &rs, nil
 }
 
 func (r *RunnerDeploymentReconciler) SetupWithManager(mgr ctrl.Manager) error {

controllers/runnerreplicaset_controller.go

@@ -31,6 +31,7 @@ import (
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 
 	"github.com/summerwind/actions-runner-controller/api/v1alpha1"
+	"github.com/summerwind/actions-runner-controller/github"
 )
 
 // RunnerReplicaSetReconciler reconciles a Runner object
@@ -39,9 +40,11 @@ type RunnerReplicaSetReconciler struct {
 	Log          logr.Logger
 	Recorder     record.EventRecorder
 	Scheme       *runtime.Scheme
+	GitHubClient *github.Client
 }
 
 // +kubebuilder:rbac:groups=actions.summerwind.dev,resources=runnerreplicasets,verbs=get;list;watch;create;update;patch;delete
+// +kubebuilder:rbac:groups=actions.summerwind.dev,resources=runnerreplicasets/finalizers,verbs=get;list;watch;create;update;patch;delete
 // +kubebuilder:rbac:groups=actions.summerwind.dev,resources=runnerreplicasets/status,verbs=get;update;patch
 // +kubebuilder:rbac:groups=actions.summerwind.dev,resources=runners,verbs=get;list;watch;create;update;patch;delete
 // +kubebuilder:rbac:groups=actions.summerwind.dev,resources=runners/status,verbs=get;update;patch
@@ -96,8 +99,25 @@ func (r *RunnerReplicaSetReconciler) Reconcile(req ctrl.Request) (ctrl.Result, e
 	if available > desired {
 		n := available - desired
 
+		// 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)
+			if err != nil {
+				log.Error(err, "Failed to check if runner is busy")
+				return ctrl.Result{}, err
+			}
+			if !busy {
+				notBusy = append(notBusy, runner)
+			}
+		}
+
+		if len(notBusy) < n {
+			n = len(notBusy)
+		}
+
 		for i := 0; i < n; i++ {
-			if err := r.Client.Delete(ctx, &myRunners[i]); err != nil {
+			if err := r.Client.Delete(ctx, &notBusy[i]); err != nil {
 				log.Error(err, "Failed to delete runner resource")
 
 				return ctrl.Result{}, err
@@ -166,3 +186,19 @@ 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/runnerreplicaset_controller_test.go

@@ -3,11 +3,14 @@ package controllers
 import (
 	"context"
 	"math/rand"
+	"net/http/httptest"
 	"time"
 
+	"github.com/google/go-github/v32/github"
 	corev1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/types"
 	"k8s.io/client-go/kubernetes/scheme"
+	"k8s.io/utils/pointer"
 	ctrl "sigs.k8s.io/controller-runtime"
 	logf "sigs.k8s.io/controller-runtime/pkg/log"
 
@@ -17,6 +20,12 @@ import (
 	"sigs.k8s.io/controller-runtime/pkg/client"
 
 	actionsv1alpha1 "github.com/summerwind/actions-runner-controller/api/v1alpha1"
+	"github.com/summerwind/actions-runner-controller/github/fake"
+)
+
+var (
+	runnersList *fake.RunnersList
+	server      *httptest.Server
 )
 
 // SetupTest will set up a testing environment.
@@ -41,11 +50,16 @@ func SetupTest(ctx context.Context) *corev1.Namespace {
 		mgr, err := ctrl.NewManager(cfg, ctrl.Options{})
 		Expect(err).NotTo(HaveOccurred(), "failed to create manager")
 
+		runnersList = fake.NewRunnersList()
+		server = runnersList.GetServer()
+		ghClient := newGithubClient(server)
+
 		controller := &RunnerReplicaSetReconciler{
 			Client:       mgr.GetClient(),
 			Scheme:       scheme.Scheme,
 			Log:          logf.Log,
 			Recorder:     mgr.GetEventRecorderFor("runnerreplicaset-controller"),
+			GitHubClient: ghClient,
 		}
 		err = controller.SetupWithManager(mgr)
 		Expect(err).NotTo(HaveOccurred(), "failed to setup controller")
@@ -61,6 +75,7 @@ func SetupTest(ctx context.Context) *corev1.Namespace {
 	AfterEach(func() {
 		close(stopCh)
 
+		server.Close()
 		err := k8sClient.Delete(ctx, ns)
 		Expect(err).NotTo(HaveOccurred(), "failed to delete test namespace")
 	})
@@ -124,6 +139,16 @@ var _ = Context("Inside of a new namespace", func() {
 							logf.Log.Error(err, "list runners")
 						}
 
+						for i, runner := range runners.Items {
+							runnersList.Add(&github.Runner{
+								ID:     pointer.Int64Ptr(int64(i) + 1),
+								Name:   pointer.StringPtr(runner.Name),
+								OS:     pointer.StringPtr("linux"),
+								Status: pointer.StringPtr("online"),
+								Busy:   pointer.BoolPtr(false),
+							})
+						}
+
 						return len(runners.Items)
 					},
 					time.Second*5, time.Millisecond*500).Should(BeEquivalentTo(1))
@@ -155,6 +180,16 @@ var _ = Context("Inside of a new namespace", func() {
 							logf.Log.Error(err, "list runners")
 						}
 
+						for i, runner := range runners.Items {
+							runnersList.Add(&github.Runner{
+								ID:     pointer.Int64Ptr(int64(i) + 1),
+								Name:   pointer.StringPtr(runner.Name),
+								OS:     pointer.StringPtr("linux"),
+								Status: pointer.StringPtr("online"),
+								Busy:   pointer.BoolPtr(false),
+							})
+						}
+
 						return len(runners.Items)
 					},
 					time.Second*5, time.Millisecond*500).Should(BeEquivalentTo(2))
@@ -186,6 +221,16 @@ var _ = Context("Inside of a new namespace", func() {
 							logf.Log.Error(err, "list runners")
 						}
 
+						for i, runner := range runners.Items {
+							runnersList.Add(&github.Runner{
+								ID:     pointer.Int64Ptr(int64(i) + 1),
+								Name:   pointer.StringPtr(runner.Name),
+								OS:     pointer.StringPtr("linux"),
+								Status: pointer.StringPtr("online"),
+								Busy:   pointer.BoolPtr(false),
+							})
+						}
+
 						return len(runners.Items)
 					},
 					time.Second*5, time.Millisecond*500).Should(BeEquivalentTo(0))

github/fake/fake.go

@@ -4,7 +4,10 @@ import (
 	"fmt"
 	"net/http"
 	"net/http/httptest"
+	"strconv"
+	"strings"
 	"time"
+	"unicode"
 )
 
 const (
@@ -14,109 +17,144 @@ const (
 {
   "total_count": 2,
   "runners": [
-    {"id": 1, "name": "test1", "os": "linux", "status": "online"},
-    {"id": 2, "name": "test2", "os": "linux", "status": "offline"}
+    {"id": 1, "name": "test1", "os": "linux", "status": "online", "busy": false},
+    {"id": 2, "name": "test2", "os": "linux", "status": "offline", "busy": false}
   ]
 }
 `
 )
 
-type handler struct {
+type Handler struct {
 	Status int
 	Body   string
 }
 
-func (h *handler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+func (h *Handler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 	w.WriteHeader(h.Status)
 	fmt.Fprintf(w, h.Body)
 }
 
+type MapHandler struct {
+	Status int
+	Bodies map[int]string
+}
+
+func (h *MapHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	// Parse out int key from URL path
+	key, err := strconv.Atoi(strings.TrimFunc(req.URL.Path, func(r rune) bool { return !unicode.IsNumber(r) }))
+	if err != nil {
+		w.WriteHeader(400)
+	} else if body := h.Bodies[key]; len(body) == 0 {
+		w.WriteHeader(404)
+	} else {
+		w.WriteHeader(h.Status)
+		fmt.Fprintf(w, body)
+	}
+}
+
+type ServerConfig struct {
+	*FixedResponses
+}
+
 // NewServer creates a fake server for running unit tests
-func NewServer() *httptest.Server {
-	routes := map[string]handler{
+func NewServer(opts ...Option) *httptest.Server {
+	config := ServerConfig{
+		FixedResponses: &FixedResponses{},
+	}
+
+	for _, o := range opts {
+		o(&config)
+	}
+
+	routes := map[string]http.Handler{
 		// For CreateRegistrationToken
-		"/repos/test/valid/actions/runners/registration-token": handler{
+		"/repos/test/valid/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)),
 		},
-		"/repos/test/invalid/actions/runners/registration-token": handler{
+		"/repos/test/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)),
 		},
-		"/repos/test/error/actions/runners/registration-token": handler{
+		"/repos/test/error/actions/runners/registration-token": &Handler{
 			Status: http.StatusBadRequest,
 			Body:   "",
 		},
-		"/orgs/test/actions/runners/registration-token": handler{
+		"/orgs/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)),
 		},
-		"/orgs/invalid/actions/runners/registration-token": handler{
+		"/orgs/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)),
 		},
-		"/orgs/error/actions/runners/registration-token": handler{
+		"/orgs/error/actions/runners/registration-token": &Handler{
 			Status: http.StatusBadRequest,
 			Body:   "",
 		},
 
 		// For ListRunners
-		"/repos/test/valid/actions/runners": handler{
+		"/repos/test/valid/actions/runners": &Handler{
 			Status: http.StatusOK,
 			Body:   RunnersListBody,
 		},
-		"/repos/test/invalid/actions/runners": handler{
+		"/repos/test/invalid/actions/runners": &Handler{
 			Status: http.StatusNoContent,
 			Body:   "",
 		},
-		"/repos/test/error/actions/runners": handler{
+		"/repos/test/error/actions/runners": &Handler{
 			Status: http.StatusBadRequest,
 			Body:   "",
 		},
-		"/orgs/test/actions/runners": handler{
+		"/orgs/test/actions/runners": &Handler{
 			Status: http.StatusOK,
 			Body:   RunnersListBody,
 		},
-		"/orgs/invalid/actions/runners": handler{
+		"/orgs/invalid/actions/runners": &Handler{
 			Status: http.StatusNoContent,
 			Body:   "",
 		},
-		"/orgs/error/actions/runners": handler{
+		"/orgs/error/actions/runners": &Handler{
 			Status: http.StatusBadRequest,
 			Body:   "",
 		},
 
 		// For RemoveRunner
-		"/repos/test/valid/actions/runners/1": handler{
+		"/repos/test/valid/actions/runners/1": &Handler{
 			Status: http.StatusNoContent,
 			Body:   "",
 		},
-		"/repos/test/invalid/actions/runners/1": handler{
+		"/repos/test/invalid/actions/runners/1": &Handler{
 			Status: http.StatusOK,
 			Body:   "",
 		},
-		"/repos/test/error/actions/runners/1": handler{
+		"/repos/test/error/actions/runners/1": &Handler{
 			Status: http.StatusBadRequest,
 			Body:   "",
 		},
-		"/orgs/test/actions/runners/1": handler{
+		"/orgs/test/actions/runners/1": &Handler{
 			Status: http.StatusNoContent,
 			Body:   "",
 		},
-		"/orgs/invalid/actions/runners/1": handler{
+		"/orgs/invalid/actions/runners/1": &Handler{
 			Status: http.StatusOK,
 			Body:   "",
 		},
-		"/orgs/error/actions/runners/1": handler{
+		"/orgs/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,
+
+		// For auto-scaling based on the number of queued(pending) workflow jobs
+		"/repos/test/valid/actions/runs/": config.FixedResponses.ListWorkflowJobs,
 	}
 
 	mux := http.NewServeMux()
 	for path, handler := range routes {
-		h := handler
-		mux.Handle(path, &h)
+		mux.Handle(path, handler)
 	}
 
 	return httptest.NewServer(mux)

github/fake/options.go

@@ -0,0 +1,32 @@
+package fake
+
+type FixedResponses struct {
+	ListRepositoryWorkflowRuns *Handler
+	ListWorkflowJobs           *MapHandler
+}
+
+type Option func(*ServerConfig)
+
+func WithListRepositoryWorkflowRunsResponse(status int, body string) Option {
+	return func(c *ServerConfig) {
+		c.FixedResponses.ListRepositoryWorkflowRuns = &Handler{
+			Status: status,
+			Body:   body,
+		}
+	}
+}
+
+func WithListWorkflowJobsResponse(status int, bodies map[int]string) Option {
+	return func(c *ServerConfig) {
+		c.FixedResponses.ListWorkflowJobs = &MapHandler{
+			Status: status,
+			Bodies: bodies,
+		}
+	}
+}
+
+func WithFixedResponses(responses *FixedResponses) Option {
+	return func(c *ServerConfig) {
+		c.FixedResponses = responses
+	}
+}

github/fake/runners.go

@@ -0,0 +1,74 @@
+package fake
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"strconv"
+
+	"github.com/google/go-github/v32/github"
+	"github.com/gorilla/mux"
+)
+
+type RunnersList struct {
+	runners []*github.Runner
+}
+
+func NewRunnersList() *RunnersList {
+	return &RunnersList{
+		runners: make([]*github.Runner, 0),
+	}
+}
+
+func (r *RunnersList) Add(runner *github.Runner) {
+	if !exists(r.runners, runner) {
+		r.runners = append(r.runners, 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/{id}", r.handleRemove())
+	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 {
+	return func(w http.ResponseWriter, res *http.Request) {
+		j, err := json.Marshal(github.Runners{
+			TotalCount: len(r.runners),
+			Runners:    r.runners,
+		})
+		if err != nil {
+			panic(err)
+		}
+
+		w.WriteHeader(http.StatusOK)
+		w.Write(j)
+	}
+}
+
+func (r *RunnersList) handleRemove() http.HandlerFunc {
+	return func(w http.ResponseWriter, res *http.Request) {
+		vars := mux.Vars(res)
+		for i, runner := range r.runners {
+			if runner.ID != nil && vars["id"] == strconv.FormatInt(*runner.ID, 10) {
+				r.runners = append(r.runners[:i], r.runners[i+1:]...)
+			}
+		}
+		w.WriteHeader(http.StatusOK)
+	}
+}
+
+func exists(runners []*github.Runner, runner *github.Runner) bool {
+	for _, r := range runners {
+		if *r.Name == *runner.Name {
+			return true
+		}
+	}
+	return false
+}

github/github.go

@@ -4,46 +4,75 @@ import (
 	"context"
 	"fmt"
 	"net/http"
+	"net/url"
 	"strings"
 	"sync"
 	"time"
 
 	"github.com/bradleyfalzon/ghinstallation"
-	"github.com/google/go-github/v31/github"
+	"github.com/google/go-github/v32/github"
 	"golang.org/x/oauth2"
 )
 
+// Config contains configuration for Github client
+type Config struct {
+	EnterpriseURL     string `split_words:"true"`
+	AppID             int64  `split_words:"true"`
+	AppInstallationID int64  `split_words:"true"`
+	AppPrivateKey     string `split_words:"true"`
+	Token             string
+}
+
 // Client wraps GitHub client with some additional
 type Client struct {
 	*github.Client
 	regTokens map[string]*github.RegistrationToken
 	mu        sync.Mutex
+	// GithubBaseURL to Github without API suffix.
+	GithubBaseURL string
 }
 
-// NewClient returns a client authenticated as a GitHub App.
-func NewClient(appID, installationID int64, privateKeyPath string) (*Client, error) {
-	tr, err := ghinstallation.NewKeyFromFile(http.DefaultTransport, appID, installationID, privateKeyPath)
+func (c *Config) NewClient() (*Client, error) {
+	var (
+		httpClient *http.Client
+		client     *github.Client
+	)
+	githubBaseURL := "https://github.com/"
+	if len(c.Token) > 0 {
+		httpClient = oauth2.NewClient(context.Background(), oauth2.StaticTokenSource(
+			&oauth2.Token{AccessToken: c.Token},
+		))
+	} else {
+		tr, err := ghinstallation.NewKeyFromFile(http.DefaultTransport, c.AppID, c.AppInstallationID, c.AppPrivateKey)
 		if err != nil {
 			return nil, fmt.Errorf("authentication failed: %v", err)
 		}
-
-	return &Client{
-		Client:    github.NewClient(&http.Client{Transport: tr}),
-		regTokens: map[string]*github.RegistrationToken{},
-		mu:        sync.Mutex{},
-	}, nil
+		if len(c.EnterpriseURL) > 0 {
+			githubAPIURL, err := getEnterpriseApiUrl(c.EnterpriseURL)
+			if err != nil {
+				return nil, fmt.Errorf("enterprise url incorrect: %v", err)
+			}
+			tr.BaseURL = githubAPIURL
+		}
+		httpClient = &http.Client{Transport: tr}
 	}
 
-// NewClientWithAccessToken returns a client authenticated with personal access token.
-func NewClientWithAccessToken(token string) (*Client, error) {
-	tc := oauth2.NewClient(context.Background(), oauth2.StaticTokenSource(
-		&oauth2.Token{AccessToken: token},
-	))
+	if len(c.EnterpriseURL) > 0 {
+		var err error
+		client, err = github.NewEnterpriseClient(c.EnterpriseURL, c.EnterpriseURL, httpClient)
+		if err != nil {
+			return nil, fmt.Errorf("enterprise client creation failed: %v", err)
+		}
+		githubBaseURL = fmt.Sprintf("%s://%s%s", client.BaseURL.Scheme, client.BaseURL.Host, strings.TrimSuffix(client.BaseURL.Path, "api/v3/"))
+	} else {
+		client = github.NewClient(httpClient)
+	}
 
 	return &Client{
-		Client:    github.NewClient(tc),
+		Client:        client,
 		regTokens:     map[string]*github.RegistrationToken{},
 		mu:            sync.Mutex{},
+		GithubBaseURL: githubBaseURL,
 	}, nil
 }
 
@@ -83,7 +112,7 @@ func (c *Client) GetRegistrationToken(ctx context.Context, org, repo, name strin
 	return rt, nil
 }
 
-// RemoveRunner removes a runner with specified runner ID from repocitory.
+// 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)
 
@@ -119,7 +148,7 @@ func (c *Client) ListRunners(ctx context.Context, org, repo string) ([]*github.R
 		list, res, err := c.listRunners(ctx, owner, repo, &opts)
 
 		if err != nil {
-			return runners, fmt.Errorf("failed to remove runner: %v", err)
+			return runners, fmt.Errorf("failed to list runners: %v", err)
 		}
 
 		runners = append(runners, list.Runners...)
@@ -197,3 +226,21 @@ func splitOwnerAndRepo(repo string) (string, string, error) {
 	}
 	return chunk[0], chunk[1], nil
 }
+
+func getEnterpriseApiUrl(baseURL string) (string, error) {
+	baseEndpoint, err := url.Parse(baseURL)
+	if err != nil {
+		return "", err
+	}
+	if !strings.HasSuffix(baseEndpoint.Path, "/") {
+		baseEndpoint.Path += "/"
+	}
+	if !strings.HasSuffix(baseEndpoint.Path, "/api/v3/") &&
+		!strings.HasPrefix(baseEndpoint.Host, "api.") &&
+		!strings.Contains(baseEndpoint.Host, ".api.") {
+		baseEndpoint.Path += "api/v3/"
+	}
+
+	// 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
+}

github/github_beta.go

@@ -10,7 +10,7 @@ import (
 	"net/url"
 	"reflect"
 
-	"github.com/google/go-github/v31/github"
+	"github.com/google/go-github/v32/github"
 	"github.com/google/go-querystring/query"
 )
 

github/github_test.go

@@ -7,14 +7,17 @@ import (
 	"testing"
 	"time"
 
-	"github.com/google/go-github/v31/github"
+	"github.com/google/go-github/v32/github"
 	"github.com/summerwind/actions-runner-controller/github/fake"
 )
 
 var server *httptest.Server
 
 func newTestClient() *Client {
-	client, err := NewClientWithAccessToken("token")
+	c := Config{
+		Token: "token",
+	}
+	client, err := c.NewClient()
 	if err != nil {
 		panic(err)
 	}
@@ -41,9 +44,9 @@ func TestGetRegistrationToken(t *testing.T) {
 		token string
 		err   bool
 	}{
-		{org: "test", repo: "valid", token: fake.RegistrationToken, err: false},
-		{org: "test", repo: "invalid", token: "", err: true},
-		{org: "test", repo: "error", token: "", err: true},
+		{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},
@@ -68,9 +71,9 @@ func TestListRunners(t *testing.T) {
 		length int
 		err    bool
 	}{
-		{org: "test", repo: "valid", length: 2, err: false},
-		{org: "test", repo: "invalid", length: 0, err: true},
-		{org: "test", repo: "error", length: 0, err: true},
+		{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},
@@ -94,9 +97,9 @@ func TestRemoveRunner(t *testing.T) {
 		repo string
 		err  bool
 	}{
-		{org: "test", repo: "valid", err: false},
-		{org: "test", repo: "invalid", err: true},
-		{org: "test", repo: "error", err: true},
+		{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},

go.mod

@@ -1,13 +1,15 @@
 module github.com/summerwind/actions-runner-controller
 
-go 1.13
+go 1.15
 
 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/v31 v31.0.0
+	github.com/google/go-github/v32 v32.1.1-0.20200822031813-d57a3a84ba04
 	github.com/google/go-querystring v1.0.0
+	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/stretchr/testify v1.4.0 // indirect
@@ -15,5 +17,6 @@ require (
 	k8s.io/api v0.0.0-20190918155943-95b840bb6a1f
 	k8s.io/apimachinery v0.0.0-20190913080033-27d36303b655
 	k8s.io/client-go v0.0.0-20190918160344-1fbdaa4c8d90
+	k8s.io/utils v0.0.0-20190801114015-581e00157fb1
 	sigs.k8s.io/controller-runtime v0.4.0
 )

go.sum

@@ -116,11 +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/v29 v29.0.2 h1:opYN6Wc7DOz7Ku3Oh4l7prmkOMwEcQxpFtxdU8N8Pts=
 github.com/google/go-github/v29 v29.0.2/go.mod h1:CHKiKKPHJ0REzfwc14QMklvtHwCveD0PxlMjLlzAM5E=
-github.com/google/go-github/v31 v31.0.0 h1:JJUxlP9lFK+ziXKimTCprajMApV1ecWD4NB6CCb0plo=
-github.com/google/go-github/v31 v31.0.0/go.mod h1:NQPZol8/1sMoWYGN2yaALIBytu17gAWfhbweiEed3pM=
+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-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=
@@ -136,6 +135,8 @@ github.com/googleapis/gnostic v0.0.0-20170729233727-0c5108395e2d/go.mod h1:sJBsC
 github.com/googleapis/gnostic v0.3.1 h1:WeAefnSUHlBb0iJKwxFDZdbfGwkd7xRNuV+IpXMJhYk=
 github.com/googleapis/gnostic v0.3.1/go.mod h1:on+2t9HRStVgn95RSsFWFz+6Q0Snyqv1awfrALZdbtU=
 github.com/gophercloud/gophercloud v0.1.0/go.mod h1:vxM41WHh5uqHVBMZHzuwNOHh8XEoIEcSTewFxm1c5g8=
+github.com/gorilla/mux v1.8.0 h1:i40aqfkR1h2SlN9hojwV5ZA91wcXFOvkdNIeFDP5koI=
+github.com/gorilla/mux v1.8.0/go.mod h1:DVbg23sWSpFRCP0SfiEN6jmj59UnW/n46BH5rLB71So=
 github.com/gorilla/websocket v1.4.0/go.mod h1:E7qHFY5m1UJ88s3WnNqhKjPHQ0heANvMoAMk2YaljkQ=
 github.com/gregjones/httpcache v0.0.0-20170728041850-787624de3eb7/go.mod h1:FecbI9+v66THATjSRHfNgh1IVFe/9kFxbXtjV0ctIMA=
 github.com/grpc-ecosystem/go-grpc-middleware v0.0.0-20190222133341-cfaf5686ec79/go.mod h1:FiyG127CGDf3tlThmgyCl78X/SZQqEOJBCDaAfeWzPs=
@@ -157,6 +158,8 @@ github.com/json-iterator/go v1.1.6/go.mod h1:+SdeFBvtyEkXs7REEP0seUULqWtbJapLOCV
 github.com/json-iterator/go v1.1.7 h1:KfgG9LzI+pYjr4xvmz/5H4FXjokeP+rlHLhv3iH62Fo=
 github.com/json-iterator/go v1.1.7/go.mod h1:KdQUCv79m/52Kvf8AW2vK1V8akMuk1QjK/uOdHXbAo4=
 github.com/jstemmer/go-junit-report v0.0.0-20190106144839-af01ea7f8024/go.mod h1:6v2b51hI/fHJwM22ozAgKL4VKDeJcHhJFhtBdhmNjmU=
+github.com/kelseyhightower/envconfig v1.4.0 h1:Im6hONhd3pLkfDFsbRgu68RDNkGF1r3dvMUtDTo2cv8=
+github.com/kelseyhightower/envconfig v1.4.0/go.mod h1:cccZRl6mQpaq41TPp5QxidR+Sa3axMbJDNb//FQX6Gg=
 github.com/kisielk/errcheck v1.2.0/go.mod h1:/BMXB+zMLi60iA8Vv6Ksmxu/1UDYcXs4uQLJ+jE2L00=
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
 github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=

main.go

@@ -20,8 +20,9 @@ import (
 	"flag"
 	"fmt"
 	"os"
-	"strconv"
+	"time"
 
+	"github.com/kelseyhightower/envconfig"
 	actionsv1alpha1 "github.com/summerwind/actions-runner-controller/api/v1alpha1"
 	"github.com/summerwind/actions-runner-controller/controllers"
 	"github.com/summerwind/actions-runner-controller/github"
@@ -57,82 +58,48 @@ func main() {
 
 		metricsAddr          string
 		enableLeaderElection bool
+		syncPeriod           time.Duration
 
 		runnerImage string
 		dockerImage string
-
-		ghToken             string
-		ghAppID             int64
-		ghAppInstallationID int64
-		ghAppPrivateKey     string
 	)
 
+	var c github.Config
+	err = envconfig.Process("github", &c)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, "Error: Environment variable read failed.")
+	}
+
 	flag.StringVar(&metricsAddr, "metrics-addr", ":8080", "The address the metric endpoint binds to.")
 	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.StringVar(&runnerImage, "runner-image", defaultRunnerImage, "The image name of self-hosted runner container.")
 	flag.StringVar(&dockerImage, "docker-image", defaultDockerImage, "The image name of docker sidecar container.")
-	flag.StringVar(&ghToken, "github-token", "", "The personal access token of GitHub.")
-	flag.Int64Var(&ghAppID, "github-app-id", 0, "The application ID of GitHub App.")
-	flag.Int64Var(&ghAppInstallationID, "github-app-installation-id", 0, "The installation ID of GitHub App.")
-	flag.StringVar(&ghAppPrivateKey, "github-app-private-key", "", "The path of a private key file to authenticate as a GitHub App")
+	flag.StringVar(&c.Token, "github-token", c.Token, "The personal access token of GitHub.")
+	flag.Int64Var(&c.AppID, "github-app-id", c.AppID, "The application ID of GitHub App.")
+	flag.Int64Var(&c.AppInstallationID, "github-app-installation-id", c.AppInstallationID, "The installation ID of GitHub App.")
+	flag.StringVar(&c.AppPrivateKey, "github-app-private-key", c.AppPrivateKey, "The path of a private key file to authenticate as a GitHub App")
+	flag.DurationVar(&syncPeriod, "sync-period", 10*time.Minute, "Determines the minimum frequency at which K8s resources managed by this controller are reconciled. When you use autoscaling, set to a lower value like 10 minute, because this corresponds to the minimum time to react on demand change")
 	flag.Parse()
 
-	if ghToken == "" {
-		ghToken = os.Getenv("GITHUB_TOKEN")
-	}
-	if ghAppID == 0 {
-		appID, err := strconv.ParseInt(os.Getenv("GITHUB_APP_ID"), 10, 64)
-		if err == nil {
-			ghAppID = appID
-		}
-	}
-	if ghAppInstallationID == 0 {
-		appInstallationID, err := strconv.ParseInt(os.Getenv("GITHUB_APP_INSTALLATION_ID"), 10, 64)
-		if err == nil {
-			ghAppInstallationID = appInstallationID
-		}
-	}
-	if ghAppPrivateKey == "" {
-		ghAppPrivateKey = os.Getenv("GITHUB_APP_PRIVATE_KEY")
-	}
-
-	if ghAppID != 0 {
-		if ghAppInstallationID == 0 {
-			fmt.Fprintln(os.Stderr, "Error: The installation ID must be specified.")
-			os.Exit(1)
-		}
-
-		if ghAppPrivateKey == "" {
-			fmt.Fprintln(os.Stderr, "Error: The path of a private key file must be specified.")
-			os.Exit(1)
-		}
-
-		ghClient, err = github.NewClient(ghAppID, ghAppInstallationID, ghAppPrivateKey)
-		if err != nil {
-			fmt.Fprintf(os.Stderr, "Error: Failed to create GitHub client: %v\n", err)
-			os.Exit(1)
-		}
-	} else if ghToken != "" {
-		ghClient, err = github.NewClientWithAccessToken(ghToken)
-		if err != nil {
-			fmt.Fprintf(os.Stderr, "Error: Failed to create GitHub client: %v\n", err)
-			os.Exit(1)
-		}
-	} else {
-		fmt.Fprintln(os.Stderr, "Error: GitHub App credentials or personal access token must be specified.")
-		os.Exit(1)
-	}
-
-	ctrl.SetLogger(zap.New(func(o *zap.Options) {
+	logger := zap.New(func(o *zap.Options) {
 		o.Development = true
-	}))
+	})
+
+	ghClient, err = c.NewClient()
+	if err != nil {
+		fmt.Fprintln(os.Stderr, "Error: Client creation failed.", err)
+		os.Exit(1)
+	}
+
+	ctrl.SetLogger(logger)
 
 	mgr, err := ctrl.NewManager(ctrl.GetConfigOrDie(), ctrl.Options{
 		Scheme:             scheme,
 		MetricsBindAddress: metricsAddr,
 		LeaderElection:     enableLeaderElection,
 		Port:               9443,
+		SyncPeriod:         &syncPeriod,
 	})
 	if err != nil {
 		setupLog.Error(err, "unable to start manager")
@@ -157,6 +124,7 @@ func main() {
 		Client:       mgr.GetClient(),
 		Log:          ctrl.Log.WithName("controllers").WithName("RunnerReplicaSet"),
 		Scheme:       mgr.GetScheme(),
+		GitHubClient: ghClient,
 	}
 
 	if err = runnerSetReconciler.SetupWithManager(mgr); err != nil {
@@ -175,6 +143,18 @@ func main() {
 		os.Exit(1)
 	}
 
+	horizontalRunnerAutoscaler := &controllers.HorizontalRunnerAutoscalerReconciler{
+		Client:       mgr.GetClient(),
+		Log:          ctrl.Log.WithName("controllers").WithName("HorizontalRunnerAutoscaler"),
+		Scheme:       mgr.GetScheme(),
+		GitHubClient: ghClient,
+	}
+
+	if err = horizontalRunnerAutoscaler.SetupWithManager(mgr); err != nil {
+		setupLog.Error(err, "unable to create controller", "controller", "HorizontalRunnerAutoscaler")
+		os.Exit(1)
+	}
+
 	if err = (&actionsv1alpha1.Runner{}).SetupWebhookWithManager(mgr); err != nil {
 		setupLog.Error(err, "unable to create webhook", "webhook", "Runner")
 		os.Exit(1)

runner/Dockerfile

@@ -1,7 +1,8 @@
 FROM ubuntu:18.04
 
-ARG RUNNER_VERSION
-ARG DOCKER_VERSION
+ARG TARGETPLATFORM
+ARG RUNNER_VERSION=2.272.0
+ARG DOCKER_VERSION=19.03.12
 
 ENV DEBIAN_FRONTEND=noninteractive
 RUN apt update -y \
@@ -36,26 +37,38 @@ RUN apt update -y \
   zstd \
   && rm -rf /var/lib/apt/lists/*
 
-RUN curl -L -o docker.tgz https://download.docker.com/linux/static/stable/x86_64/docker-${DOCKER_VERSION}.tgz \
+RUN export ARCH=$(echo ${TARGETPLATFORM} | cut -d / -f2) \
+  && curl -L -o /usr/local/bin/dumb-init https://github.com/Yelp/dumb-init/releases/download/v1.2.2/dumb-init_1.2.2_${ARCH} \
+  && chmod +x /usr/local/bin/dumb-init
+
+# Docker download supports arm64 as aarch64 & amd64 as x86_64
+RUN export ARCH=$(echo ${TARGETPLATFORM} | cut -d / -f2) \
+  && if [ "$ARCH" = "arm64" ]; then export ARCH=aarch64 ; fi \
+  && if [ "$ARCH" = "amd64" ]; then export ARCH=x86_64 ; fi \
+  && curl -L -o docker.tgz https://download.docker.com/linux/static/stable/${ARCH}/docker-${DOCKER_VERSION}.tgz \
   && tar zxvf docker.tgz \
   && install -o root -g root -m 755 docker/docker /usr/local/bin/docker \
   && rm -rf docker docker.tgz \
-  && curl -L -o /usr/local/bin/dumb-init https://github.com/Yelp/dumb-init/releases/download/v1.2.2/dumb-init_1.2.2_amd64 \
-  && chmod +x /usr/local/bin/dumb-init \
   && adduser --disabled-password --gecos "" --uid 1000 runner \
+  && groupadd docker \
   && usermod -aG sudo runner \
+  && usermod -aG docker runner \
   && echo "%sudo   ALL=(ALL:ALL) NOPASSWD:ALL" > /etc/sudoers
 
-RUN mkdir -p /runner \
+# Runner download supports amd64 as x64
+RUN export ARCH=$(echo ${TARGETPLATFORM} | cut -d / -f2) \
+  && if [ "$ARCH" = "amd64" ]; then export ARCH=x64 ; fi \
+  && mkdir -p /runner \
   && cd /runner \
-  && curl -L -o runner.tar.gz https://github.com/actions/runner/releases/download/v${RUNNER_VERSION}/actions-runner-linux-x64-${RUNNER_VERSION}.tar.gz \
+  && curl -L -o runner.tar.gz https://github.com/actions/runner/releases/download/v${RUNNER_VERSION}/actions-runner-linux-${ARCH}-${RUNNER_VERSION}.tar.gz \
   && tar xzf ./runner.tar.gz \
   && rm runner.tar.gz \
   && ./bin/installdependencies.sh \
   && rm -rf /var/lib/apt/lists/*
 
 COPY entrypoint.sh /runner
+COPY patched /runner/patched
 
-USER runner:runner
+USER runner
 ENTRYPOINT ["/usr/local/bin/dumb-init", "--"]
 CMD ["/runner/entrypoint.sh"]

runner/Makefile

@@ -1,11 +1,52 @@
 NAME ?= summerwind/actions-runner
+DIND_RUNNER_NAME ?= ${NAME}-dind
+TAG ?= latest
 
-RUNNER_VERSION ?= 2.169.1
-DOCKER_VERSION ?= 19.03.8
+RUNNER_VERSION ?= 2.273.5
+DOCKER_VERSION ?= 19.03.12
+
+# default list of platforms for which multiarch image is built
+ifeq (${PLATFORMS}, )
+	export PLATFORMS="linux/amd64,linux/arm64"
+endif
+
+# if IMG_RESULT is unspecified, by default the image will be pushed to registry
+ifeq (${IMG_RESULT}, load)
+	export PUSH_ARG="--load"
+    # if load is specified, image will be built only for the build machine architecture.
+    export PLATFORMS="local"
+else ifeq (${IMG_RESULT}, cache)
+	# if cache is specified, image will only be available in the build cache, it won't be pushed or loaded
+	# therefore no PUSH_ARG will be specified
+else
+	export PUSH_ARG="--push"
+endif
 
 docker-build:
-	docker build --build-arg RUNNER_VERSION=${RUNNER_VERSION} --build-arg DOCKER_VERSION=${DOCKER_VERSION} -t ${NAME}:latest -t ${NAME}:v${RUNNER_VERSION} .
+	docker build --build-arg RUNNER_VERSION=${RUNNER_VERSION} --build-arg DOCKER_VERSION=${DOCKER_VERSION} -t ${NAME}:${TAG} -t ${NAME}:v${RUNNER_VERSION} .
+	docker build --build-arg RUNNER_VERSION=${RUNNER_VERSION} --build-arg DOCKER_VERSION=${DOCKER_VERSION} -t ${DIND_RUNNER_NAME}:${TAG} -t ${DIND_RUNNER_NAME}:v${RUNNER_VERSION} -f dindrunner.Dockerfile .
+
 
 docker-push:
-	docker push ${NAME}:latest
+	docker push ${NAME}:${TAG}
 	docker push ${NAME}:v${RUNNER_VERSION}
+	docker push ${DIND_RUNNER_NAME}:${TAG}
+	docker push ${DIND_RUNNER_NAME}:v${RUNNER_VERSION}
+
+docker-buildx:
+	export DOCKER_CLI_EXPERIMENTAL=enabled
+	@if ! docker buildx ls | grep -q container-builder; then\
+		docker buildx create --platform ${PLATFORMS} --name container-builder --use;\
+	fi
+	docker buildx build --platform ${PLATFORMS} \
+		--build-arg RUNNER_VERSION=${RUNNER_VERSION} \
+		--build-arg DOCKER_VERSION=${DOCKER_VERSION} \
+		-t "${NAME}:latest" \
+		-f Dockerfile \
+		. ${PUSH_ARG}
+	docker buildx build --platform ${PLATFORMS} \
+		--build-arg RUNNER_VERSION=${RUNNER_VERSION} \
+		--build-arg DOCKER_VERSION=${DOCKER_VERSION} \
+		-t "${DIND_RUNNER_NAME}:latest" \
+		-f dindrunner.Dockerfile \
+		. ${PUSH_ARG}

runner/dindrunner.Dockerfile

@@ -0,0 +1,100 @@
+FROM ubuntu:20.04
+
+ENV DEBIAN_FRONTEND=noninteractive
+# Dev + DinD dependencies
+RUN apt update \
+    && apt install -y software-properties-common \
+    && add-apt-repository -y ppa:git-core/ppa \
+    && apt install -y \
+    build-essential \
+    curl \
+    ca-certificates \
+    dnsutils \
+    ftp \
+    git \
+    iproute2 \
+    iptables \
+    iputils-ping \
+    jq \
+    libunwind8 \
+    locales \
+    netcat \
+    openssh-client \
+    parallel \
+    rsync \
+    shellcheck \
+    sudo \
+    supervisor \
+    telnet \
+    time \
+    tzdata \
+    unzip \
+    upx \
+    wget \
+    zip \
+    zstd \
+    && rm -rf /var/lib/apt/list/*
+
+# Runner user
+RUN adduser --disabled-password --gecos "" --uid 1000 runner \
+    && groupadd docker \
+    && usermod -aG sudo runner \
+    && usermod -aG docker runner \
+    && echo "%sudo   ALL=(ALL:ALL) NOPASSWD:ALL" > /etc/sudoers
+
+ARG TARGETPLATFORM
+ARG RUNNER_VERSION=2.272.0
+ARG DOCKER_CHANNEL=stable
+ARG DOCKER_VERSION=19.03.13
+ARG DEBUG=false
+
+# Docker installation
+RUN export ARCH=$(echo ${TARGETPLATFORM} | cut -d / -f2) \
+    && if [ "$ARCH" = "arm64" ]; then export ARCH=aarch64 ; fi \
+    && if [ "$ARCH" = "amd64" ]; then export ARCH=x86_64 ; fi \
+	&& if ! curl -L -o docker.tgz "https://download.docker.com/linux/static/${DOCKER_CHANNEL}/${ARCH}/docker-${DOCKER_VERSION}.tgz"; then \
+		echo >&2 "error: failed to download 'docker-${DOCKER_VERSION}' from '${DOCKER_CHANNEL}' for '${ARCH}'"; \
+		exit 1; \
+	fi; \
+    echo "Downloaded Docker from https://download.docker.com/linux/static/${DOCKER_CHANNEL}/${ARCH}/docker-${DOCKER_VERSION}.tgz"; \
+	tar --extract \
+		--file docker.tgz \
+		--strip-components 1 \
+		--directory /usr/local/bin/ \
+	; \
+	rm docker.tgz; \
+	dockerd --version; \
+	docker --version
+
+# Runner download supports amd64 as x64
+RUN export ARCH=$(echo ${TARGETPLATFORM} | cut -d / -f2) \
+    && if [ "$ARCH" = "amd64" ]; then export ARCH=x64 ; fi \
+    && mkdir -p /runner \
+     && cd /runner \
+    && curl -L -o runner.tar.gz https://github.com/actions/runner/releases/download/v${RUNNER_VERSION}/actions-runner-linux-${ARCH}-${RUNNER_VERSION}.tar.gz \
+    && tar xzf ./runner.tar.gz \
+    && rm runner.tar.gz \
+    && ./bin/installdependencies.sh \
+    && rm -rf /var/lib/apt/lists/*
+
+
+COPY modprobe startup.sh /usr/local/bin/
+COPY supervisor/ /etc/supervisor/conf.d/
+COPY logger.sh /opt/bash-utils/logger.sh
+COPY entrypoint.sh /usr/local/bin/
+
+RUN chmod +x /usr/local/bin/startup.sh /usr/local/bin/entrypoint.sh /usr/local/bin/modprobe
+
+RUN export ARCH=$(echo ${TARGETPLATFORM} | cut -d / -f2) \
+    && curl -L -o /usr/local/bin/dumb-init https://github.com/Yelp/dumb-init/releases/download/v1.2.2/dumb-init_1.2.2_${ARCH} \
+    && chmod +x /usr/local/bin/dumb-init
+
+VOLUME /var/lib/docker
+
+COPY patched /runner/patched
+
+# No group definition, as that makes it harder to run docker.
+USER runner
+
+ENTRYPOINT ["/usr/local/bin/dumb-init", "--"]
+CMD ["startup.sh"]

runner/entrypoint.sh

@@ -1,11 +1,22 @@
 #!/bin/bash
 
+if [ -z "${GITHUB_URL}" ]; then
+  echo "Working with public GitHub" 1>&2
+  GITHUB_URL="https://github.com/"
+else
+  length=${#GITHUB_URL}
+  last_char=${GITHUB_URL:length-1:1}
+
+  [[ $last_char != "/" ]] && GITHUB_URL="$GITHUB_URL/"; :
+  echo "Github endpoint URL ${GITHUB_URL}"
+fi
+
 if [ -z "${RUNNER_NAME}" ]; then
   echo "RUNNER_NAME must be set" 1>&2
   exit 1
 fi
 
-if [ -n "${RUNNER_ORG}" -a -n "${RUNNER_REPO}" ]; then
+if [ -n "${RUNNER_ORG}" ] && [ -n "${RUNNER_REPO}" ]; then
   ATTACH="${RUNNER_ORG}/${RUNNER_REPO}"
 elif [ -n "${RUNNER_ORG}" ]; then
   ATTACH="${RUNNER_ORG}"
@@ -25,8 +36,18 @@ if [ -z "${RUNNER_TOKEN}" ]; then
   exit 1
 fi
 
+if [ -z "${RUNNER_REPO}" ] && [ -n "${RUNNER_ORG}" ] && [ -n "${RUNNER_GROUP}" ];then
+  RUNNER_GROUP_ARG="--runnergroup ${RUNNER_GROUP}"
+fi
+
 cd /runner
-./config.sh --unattended --replace --name "${RUNNER_NAME}" --url "https://github.com/${ATTACH}" --token "${RUNNER_TOKEN}" ${LABEL_ARG}
+./config.sh --unattended --replace --name "${RUNNER_NAME}" --url "${GITHUB_URL}${ATTACH}" --token "${RUNNER_TOKEN}" ${RUNNER_GROUP_ARG} ${LABEL_ARG}
+
+for f in runsvc.sh RunnerService.js; do
+  diff {bin,patched}/${f} || :
+  sudo mv bin/${f}{,.bak}
+  sudo mv {patched,bin}/${f}
+done
 
 unset RUNNER_NAME RUNNER_REPO RUNNER_TOKEN
-exec ./run.sh --once
+exec ./bin/runsvc.sh --once

runner/logger.sh

@@ -0,0 +1,24 @@
+#!/bin/sh
+# Logger from this post http://www.cubicrace.com/2016/03/log-tracing-mechnism-for-shell-scripts.html
+
+function INFO(){
+    local function_name="${FUNCNAME[1]}"
+    local msg="$1"
+    timeAndDate=`date`
+    echo "[$timeAndDate] [INFO] [${0}] $msg"
+}
+
+
+function DEBUG(){
+    local function_name="${FUNCNAME[1]}"
+    local msg="$1"
+    timeAndDate=`date`
+    echo "[$timeAndDate] [DEBUG] [${0}] $msg"
+}
+
+function ERROR(){
+    local function_name="${FUNCNAME[1]}"
+    local msg="$1"
+    timeAndDate=`date`
+    echo "[$timeAndDate] [ERROR]  $msg"
+}

runner/modprobe

@@ -0,0 +1,20 @@
+ #!/bin/sh
+set -eu
+
+# "modprobe" without modprobe
+# https://twitter.com/lucabruno/status/902934379835662336
+
+# this isn't 100% fool-proof, but it'll have a much higher success rate than simply using the "real" modprobe
+
+# Docker often uses "modprobe -va foo bar baz"
+# so we ignore modules that start with "-"
+for module; do
+	if [ "${module#-}" = "$module" ]; then
+		ip link show "$module" || true
+		lsmod | grep "$module" || true
+	fi
+done
+
+# remove /usr/local/... from PATH so we can exec the real modprobe as a last resort
+export PATH='/usr/sbin:/usr/bin:/sbin:/bin'
+exec modprobe "$@"

runner/patched/RunnerService.js

@@ -0,0 +1,91 @@
+#!/usr/bin/env node
+// Copyright (c) GitHub. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+var childProcess = require("child_process");
+var path = require("path")
+
+var supported = ['linux', 'darwin']
+
+if (supported.indexOf(process.platform) == -1) {
+    console.log('Unsupported platform: ' + process.platform);
+    console.log('Supported platforms are: ' + supported.toString());
+    process.exit(1);
+}
+
+var stopping = false;
+var listener = null;
+
+var runService = function() {
+    var listenerExePath = path.join(__dirname, '../bin/Runner.Listener');
+    var interactive = process.argv[2] === "interactive";
+
+    if(!stopping) {
+        try {
+            if (interactive) {
+                console.log('Starting Runner listener interactively');
+                listener = childProcess.spawn(listenerExePath, ['run'].concat(process.argv.slice(3)), { env: process.env });
+            } else {
+                console.log('Starting Runner listener with startup type: service');
+                listener = childProcess.spawn(listenerExePath, ['run', '--startuptype', 'service'].concat(process.argv.slice(2)), { env: process.env });
+            }
+
+            console.log('Started listener process');
+
+            listener.stdout.on('data', (data) => {
+                process.stdout.write(data.toString('utf8'));
+            });
+
+            listener.stderr.on('data', (data) => {
+                process.stdout.write(data.toString('utf8'));
+            });
+
+            listener.on('close', (code) => {
+                console.log(`Runner listener exited with error code ${code}`);
+
+                if (code === 0) {
+                    console.log('Runner listener exit with 0 return code, stop the service, no retry needed.');
+                    stopping = true;
+                } else if (code === 1) {
+                    console.log('Runner listener exit with terminated error, stop the service, no retry needed.');
+                    stopping = true;
+                } else if (code === 2) {
+                    console.log('Runner listener exit with retryable error, re-launch runner in 5 seconds.');
+                } else if (code === 3) {
+                    console.log('Runner listener exit because of updating, re-launch runner in 5 seconds.');
+                } else {
+                    console.log('Runner listener exit with undefined return code, re-launch runner in 5 seconds.');
+                }
+
+                if(!stopping) {
+                    setTimeout(runService, 5000);
+                }
+            });
+
+        } catch(ex) {
+            console.log(ex);
+        }
+    }
+}
+
+runService();
+console.log('Started running service');
+
+var gracefulShutdown = function(code) {
+    console.log('Shutting down runner listener');
+    stopping = true;
+    if (listener) {
+        console.log('Sending SIGINT to runner listener to stop');
+        listener.kill('SIGINT');
+
+        // TODO wait for 30 seconds and send a SIGKILL
+    }
+}
+
+process.on('SIGINT', () => {
+    gracefulShutdown(0);
+});
+
+process.on('SIGTERM', () => {
+    gracefulShutdown(0);
+});

runner/patched/runsvc.sh

@@ -0,0 +1,20 @@
+#!/bin/bash
+
+# convert SIGTERM signal to SIGINT
+# for more info on how to propagate SIGTERM to a child process see: http://veithen.github.io/2014/11/16/sigterm-propagation.html
+trap 'kill -INT $PID' TERM INT
+
+if [ -f ".path" ]; then
+    # configure
+    export PATH=`cat .path`
+    echo ".path=${PATH}"
+fi
+
+# insert anything to setup env when running as a service
+
+# run the host process which keep the listener alive
+./externals/node12/bin/node ./bin/RunnerService.js $* &
+PID=$!
+wait $PID
+trap - TERM INT
+wait $PID

runner/startup.sh

@@ -0,0 +1,37 @@
+#!/bin/bash
+source /opt/bash-utils/logger.sh
+
+function wait_for_process () {
+    local max_time_wait=30
+    local process_name="$1"
+    local waited_sec=0
+    while ! pgrep "$process_name" >/dev/null && ((waited_sec < max_time_wait)); do
+        INFO "Process $process_name is not running yet. Retrying in 1 seconds"
+        INFO "Waited $waited_sec seconds of $max_time_wait seconds"
+        sleep 1
+        ((waited_sec=waited_sec+1))
+        if ((waited_sec >= max_time_wait)); then
+            return 1
+        fi
+    done
+    return 0
+}
+
+INFO "Starting supervisor"
+sudo /usr/bin/supervisord -n >> /dev/null 2>&1 &
+
+INFO "Waiting for processes to be running"
+processes=(dockerd)
+
+for process in "${processes[@]}"; do
+    wait_for_process "$process"
+    if [ $? -ne 0 ]; then
+        ERROR "$process is not running after max time"
+        exit 1
+    else 
+        INFO "$process is running"
+    fi
+done
+
+# Wait processes to be running
+entrypoint.sh

runner/supervisor/dockerd.conf

@@ -0,0 +1,6 @@
+[program:dockerd]
+command=/usr/local/bin/dockerd
+autostart=true
+autorestart=true
+stderr_logfile=/var/log/dockerd.err.log
+stdout_logfile=/var/log/dockerd.out.log