Add GitHub Actions to publish helm chart (#257)

* Add chart workflows (#1)

* Add chart workflows

* Fix publishing step in CI

Signed-off-by: David Young <davidy@funkypenguin.co.nz>

* Update CI on push-to-master (#3)

* Put helm installation step in the correct CI job

Signed-off-by: David Young <davidy@funkypenguin.co.nz>

* Put helm installation step in the correct CI job (#4)

* Update on-push-master-publish-chart.yml

* Remove references to certmanager dependency

Signed-off-by: David Young <davidy@funkypenguin.co.nz>

* Add ability to customize kube-rbac-proxy image

Signed-off-by: David Young <davidy@funkypenguin.co.nz>

* Only install cert-manager if we're going to spin up KinD

Signed-off-by: David Young <davidy@funkypenguin.co.nz>

.github/workflows/build-runner.yml

@@ -27,7 +27,7 @@ jobs:
           - name: actions-runner-dind
             dockerfile: dindrunner.Dockerfile
     env:
-      RUNNER_VERSION: 2.274.2
+      RUNNER_VERSION: 2.275.1
       DOCKER_VERSION: 19.03.12
       DOCKERHUB_USERNAME: ${{ github.repository_owner }}
     steps:

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

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

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

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

README.md

@@ -25,7 +25,7 @@ kubectl apply -f https://github.com/summerwind/actions-runner-controller/release
 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>
+kubectl set env deploy controller-manager -c manager GITHUB_ENTERPRISE_URL=<GHEC/S URL> --namespace actions-runner-system
 ```
 
 [Enterprise level](https://docs.github.com/en/enterprise-server@2.22/actions/hosting-your-own-runners/adding-self-hosted-runners#adding-a-self-hosted-runner-to-an-enterprise) runners are not working yet as there's no API definition for those.
@@ -267,6 +267,28 @@ spec:
     - summerwind/actions-runner-controller
 ```
 
+If you do not want to manage an explicit list of repositories to scale, an alternate autoscaling scheme that can be applied is the PercentageRunnersBusy scheme. The number of desired pods are evaulated by checking how many runners are currently busy and applying a scaleup or scale down factor if certain thresholds are met. By setting the metric type to PercentageRunnersBusy, the HorizontalRunnerAutoscaler will query github for the number of busy runners which live in the RunnerDeployment namespace. Scaleup and scaledown thresholds are the percentage of busy runners at which the number of desired runners are re-evaluated. Scaleup and scaledown factors are the multiplicative factor applied to the current number of runners used to calculate the number of desired runners. This scheme is also especially useful if you want multiple controllers in various clusters, each responsible for scaling their own runner pods per namespace.
+
+```yaml
+---
+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: PercentageRunnersBusy
+    scaleUpThreshold: '0.75'
+    scaleDownThreshold: '0.3'
+    scaleUpFactor: '1.4'
+    scaleDownFactor: '0.7'
+```
+
 ## 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.
@@ -321,7 +343,7 @@ spec:
         requests:
           cpu: "2.0"
           memory: "4Gi"
-      # If set to false, there are no privileged container and you cannot use docker. 
+      # If set to false, there are no privileged container and you cannot use docker.
       dockerEnabled: false
       # If set to true, runner pod container only 1 container that's expected to be able to run docker, too.
       # image summerwind/actions-runner-dind or custom one should be used with true -value
@@ -387,7 +409,7 @@ Note that if you specify `self-hosted` in your workflow, then this will run your
 
 ## Runner Groups
 
-Runner groups can be used to limit which repositories are able to use the GitHub Runner at an Organisation level.
+Runner groups can be used to limit which repositories are able to use the GitHub Runner at an Organisation level. Runner groups have to be [created in GitHub first](https://docs.github.com/en/actions/hosting-your-own-runners/managing-access-to-self-hosted-runners-using-groups) before they can be referenced.
 
 To add the runner to the group `NewGroup`, specify the group in your `Runner` or `RunnerDeployment` spec.
 
@@ -446,11 +468,11 @@ The virtual environments from GitHub contain a lot more software packages (diffe
 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:
 
 ```shell
-FROM summerwind/actions-runner:v2.169.1
+FROM summerwind/actions-runner:latest
 
 RUN sudo apt update -y \
-  && apt install YOUR_PACKAGE
-  && rm -rf /var/lib/apt/lists/*
+  && sudo apt install YOUR_PACKAGE
+  && sudo rm -rf /var/lib/apt/lists/*
 ```
 
 You can then configure the runner to use a custom docker image by configuring the `image` field of a `Runner` or `RunnerDeployment`:

api/v1alpha1/horizontalrunnerautoscaler_types.go

@@ -56,6 +56,26 @@ type MetricSpec struct {
 	// For example, a repository name is the REPO part of `github.com/USER/REPO`.
 	// +optional
 	RepositoryNames []string `json:"repositoryNames,omitempty"`
+
+	// ScaleUpThreshold is the percentage of busy runners greater than which will
+	// trigger the hpa to scale runners up.
+	// +optional
+	ScaleUpThreshold string `json:"scaleUpThreshold,omitempty"`
+
+	// ScaleDownThreshold is the percentage of busy runners less than which will
+	// trigger the hpa to scale the runners down.
+	// +optional
+	ScaleDownThreshold string `json:"scaleDownThreshold,omitempty"`
+
+	// ScaleUpFactor is the multiplicative factor applied to the current number of runners used
+	// to determine how many pods should be added.
+	// +optional
+	ScaleUpFactor string `json:"scaleUpFactor,omitempty"`
+
+	// ScaleDownFactor is the multiplicative factor applied to the current number of runners used
+	// to determine how many pods should be removed.
+	// +optional
+	ScaleDownFactor string `json:"scaleDownFactor,omitempty"`
 }
 
 type HorizontalRunnerAutoscalerStatus struct {

api/v1alpha1/runnerdeployment_types.go

@@ -22,6 +22,7 @@ import (
 
 const (
 	AutoscalingMetricTypeTotalNumberOfQueuedAndInProgressWorkflowRuns = "TotalNumberOfQueuedAndInProgressWorkflowRuns"
+	AutoscalingMetricTypePercentageRunnersBusy                        = "PercentageRunnersBusy"
 )
 
 // RunnerReplicaSetSpec defines the desired state of RunnerDeployment

charts/.ci/ct-config.yaml

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

charts/.ci/lint-config.yaml

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

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

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

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

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

charts/actions-runner-controller/Chart.yaml

@@ -15,9 +15,22 @@ type: application
 # This is the chart version. This version number should be incremented each time you make changes
 # to the chart and its templates, including the app version.
 # Versions are expected to follow Semantic Versioning (https://semver.org/)
-version: 0.1.0
+version: 0.1.2
 
 # This is the version number of the application being deployed. This version number should be
 # incremented each time you make changes to the application. Versions are not expected to
 # follow Semantic Versioning. They should reflect the version the application is using.
-appVersion: 0.11.2
+appVersion: 0.16.0
+
+home: https://github.com/summerwind/actions-runner-controller
+
+sources:
+    - https://github.com/summerwind/actions-runner-controller
+
+maintainers:
+    - name: summerwind
+      email: contact@summerwind.jp
+      url: https://github.com/summerwind
+    - name: funkypenguin
+      email: davidy@funkypenguin.co.nz
+      url: https://www.funkypenguin.co.nz

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

@@ -0,0 +1,27 @@
+# This file sets some opinionated values for kube-score to use
+# when parsing the chart
+image:
+  pullPolicy: Always
+
+podSecurityContext:
+  fsGroup: 2000
+
+securityContext: 
+  capabilities:
+    drop:
+    - ALL
+  readOnlyRootFilesystem: true
+  runAsNonRoot: true
+  runAsUser: 2000
+
+resources: 
+  limits:
+    cpu: 100m
+    memory: 128Mi
+  requests:
+    cpu: 100m
+    memory: 128Mi  
+
+# Set the following to true to create a dummy secret, allowing the manager pod to start
+# This is only useful in CI
+createDummySecret: true

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

@@ -64,6 +64,24 @@ spec:
                     items:
                       type: string
                     type: array
+                  scaleDownFactor:
+                    description: ScaleDownFactor is the multiplicative factor applied
+                      to the current number of runners used to determine how many
+                      pods should be removed.
+                    type: string
+                  scaleDownThreshold:
+                    description: ScaleDownThreshold is the percentage of busy runners
+                      less than which will trigger the hpa to scale the runners down.
+                    type: string
+                  scaleUpFactor:
+                    description: ScaleUpFactor is the multiplicative factor applied
+                      to the current number of runners used to determine how many
+                      pods should be added.
+                    type: string
+                  scaleUpThreshold:
+                    description: ScaleUpThreshold is the percentage of busy runners
+                      greater than which will trigger the hpa to scale runners up.
+                    type: string
                   type:
                     description: Type is the type of metric to be used for autoscaling.
                       The only supported Type is TotalNumberOfQueuedAndInProgressWorkflowRuns

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

@@ -40,6 +40,9 @@ helm.sh/chart: {{ include "actions-runner-controller.chart" . }}
 app.kubernetes.io/version: {{ .Chart.AppVersion | quote }}
 {{- end }}
 app.kubernetes.io/managed-by: {{ .Release.Service }}
+{{- range $k, $v := .Values.labels }}
+{{ $k }}: {{ $v }}
+{{- end }}
 {{- end }}
 
 {{/*
@@ -86,7 +89,7 @@ Create the name of the service account to use
 {{- end }}
 
 {{- define "actions-runner-controller.authProxyServiceName" -}}
-{{- include "actions-runner-controller.fullname" . }}-controller-manager-metrics-service
+{{- include "actions-runner-controller.fullname" . }}-metrics-service
 {{- end }}
 
 {{- define "actions-runner-controller.selfsignedIssuerName" -}}

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

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

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

@@ -33,6 +33,7 @@ spec:
         - "--metrics-addr=127.0.0.1:8080"
         - "--enable-leader-election"
         - "--sync-period={{ .Values.syncPeriod }}"
+        - "--docker-image={{ .Values.image.dindSidecarRepositoryAndTag }}"
         command:
         - "/manager"
         env:
@@ -65,10 +66,14 @@ spec:
           protocol: TCP
         resources:
           {{- toYaml .Values.resources | nindent 12 }}
+        securityContext:
+          {{- toYaml .Values.securityContext | nindent 12 }}          
         volumeMounts:
         - mountPath: "/etc/actions-runner-controller"
           name: controller-manager
           readOnly: true
+        - mountPath: /tmp
+          name: tmp         
         - mountPath: /tmp/k8s-webhook-server/serving-certs
           name: cert
           readOnly: true
@@ -77,11 +82,16 @@ spec:
         - "--upstream=http://127.0.0.1:8080/"
         - "--logtostderr=true"
         - "--v=10"
-        image: gcr.io/kubebuilder/kube-rbac-proxy:v0.4.1
+        image: "{{ .Values.kube_rbac_proxy.image.repository }}:{{ .Values.kube_rbac_proxy.image.tag }}"
         name: kube-rbac-proxy
+        imagePullPolicy: {{ .Values.image.pullPolicy }}
         ports:
         - containerPort: 8443
           name: https
+        resources:
+          {{- toYaml .Values.resources | nindent 12 }}   
+        securityContext:
+          {{- toYaml .Values.securityContext | nindent 12 }}     
       terminationGracePeriodSeconds: 10
       volumes:
       - name: controller-manager
@@ -91,6 +101,8 @@ spec:
         secret:
           defaultMode: 420
           secretName: webhook-server-cert
+      - name: tmp
+        emptyDir: {}
       {{- with .Values.nodeSelector }}
       nodeSelector:
         {{- toYaml . | nindent 8 }}

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

@@ -0,0 +1,14 @@
+{{- if or .Values.authSecret.enabled }}
+apiVersion: v1
+kind: Secret
+metadata:
+  name: controller-manager
+  namespace: {{ .Release.Namespace }}
+  labels:
+    {{- include "actions-runner-controller.labels" . | nindent 4 }}
+type: Opaque
+data:
+{{- range $k, $v := .Values.authSecret }}
+  {{ $k }}: {{ $v | toString | b64enc }}
+{{- end }} 
+{{- end }}

charts/actions-runner-controller/values.yaml

@@ -2,15 +2,34 @@
 # This is a YAML-formatted file.
 # Declare variables to be passed into your templates.
 
+labels: {}
+
 replicaCount: 1
 
 syncPeriod: 10m
 
+# Only 1 authentication method can be deployed at a time
+# Uncomment the configuration you are applying and fill in the details
+authSecret:
+  enabled: false
+  ### GitHub Apps Configuration
+  #github_app_id: ""
+  #github_app_installation_id: ""
+  #github_app_private_key: |
+  ### GitHub PAT Configuration
+  #github_token: ""
+
 image:
   repository: summerwind/actions-runner-controller
+  # Overrides the manager image tag whose default is the chart appVersion if the tag key is commented out
+  tag: "latest"
+  dindSidecarRepositoryAndTag: "docker:dind"
   pullPolicy: IfNotPresent
-  # Overrides the image tag whose default is the chart appVersion.
-  tag: ""
+
+kube_rbac_proxy:
+  image:
+    repository: gcr.io/kubebuilder/kube-rbac-proxy
+    tag: v0.4.1
 
 imagePullSecrets: []
 nameOverride: ""
@@ -83,4 +102,4 @@ affinity: {}
 # Leverage a PriorityClass to ensure your pods survive resource shortages
 # ref: https://kubernetes.io/docs/concepts/configuration/pod-priority-preemption/
 # PriorityClass: system-cluster-critical
-priorityClassName: ""
+priorityClassName: ""

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

@@ -64,6 +64,24 @@ spec:
                     items:
                       type: string
                     type: array
+                  scaleDownFactor:
+                    description: ScaleDownFactor is the multiplicative factor applied
+                      to the current number of runners used to determine how many
+                      pods should be removed.
+                    type: string
+                  scaleDownThreshold:
+                    description: ScaleDownThreshold is the percentage of busy runners
+                      less than which will trigger the hpa to scale the runners down.
+                    type: string
+                  scaleUpFactor:
+                    description: ScaleUpFactor is the multiplicative factor applied
+                      to the current number of runners used to determine how many
+                      pods should be added.
+                    type: string
+                  scaleUpThreshold:
+                    description: ScaleUpThreshold is the percentage of busy runners
+                      greater than which will trigger the hpa to scale runners up.
+                    type: string
                   type:
                     description: Type is the type of metric to be used for autoscaling.
                       The only supported Type is TotalNumberOfQueuedAndInProgressWorkflowRuns

controllers/autoscaling.go

@@ -4,9 +4,19 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"math"
+	"strconv"
 	"strings"
 
 	"github.com/summerwind/actions-runner-controller/api/v1alpha1"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+)
+
+const (
+	defaultScaleUpThreshold   = 0.8
+	defaultScaleDownThreshold = 0.3
+	defaultScaleUpFactor      = 1.3
+	defaultScaleDownFactor    = 0.7
 )
 
 func (r *HorizontalRunnerAutoscalerReconciler) determineDesiredReplicas(rd v1alpha1.RunnerDeployment, hra v1alpha1.HorizontalRunnerAutoscaler) (*int, error) {
@@ -16,8 +26,20 @@ func (r *HorizontalRunnerAutoscalerReconciler) determineDesiredReplicas(rd v1alp
 		return nil, fmt.Errorf("horizontalrunnerautoscaler %s/%s is missing maxReplicas", hra.Namespace, hra.Name)
 	}
 
-	var repos [][]string
+	metrics := hra.Spec.Metrics
+	if len(metrics) == 0 || metrics[0].Type == v1alpha1.AutoscalingMetricTypeTotalNumberOfQueuedAndInProgressWorkflowRuns {
+		return r.calculateReplicasByQueuedAndInProgressWorkflowRuns(rd, hra)
+	} else if metrics[0].Type == v1alpha1.AutoscalingMetricTypePercentageRunnersBusy {
+		return r.calculateReplicasByPercentageRunnersBusy(rd, hra)
+	} else {
+		return nil, fmt.Errorf("validting autoscaling metrics: unsupported metric type %q", metrics[0].Type)
+	}
+}
 
+func (r *HorizontalRunnerAutoscalerReconciler) calculateReplicasByQueuedAndInProgressWorkflowRuns(rd v1alpha1.RunnerDeployment, hra v1alpha1.HorizontalRunnerAutoscaler) (*int, error) {
+
+	var repos [][]string
+	metrics := hra.Spec.Metrics
 	repoID := rd.Spec.Template.Spec.Repository
 	if repoID == "" {
 		orgName := rd.Spec.Template.Spec.Organization
@@ -25,13 +47,7 @@ func (r *HorizontalRunnerAutoscalerReconciler) determineDesiredReplicas(rd v1alp
 			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 {
+		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")
 		}
 
@@ -135,3 +151,99 @@ func (r *HorizontalRunnerAutoscalerReconciler) determineDesiredReplicas(rd v1alp
 
 	return &replicas, nil
 }
+
+func (r *HorizontalRunnerAutoscalerReconciler) calculateReplicasByPercentageRunnersBusy(rd v1alpha1.RunnerDeployment, hra v1alpha1.HorizontalRunnerAutoscaler) (*int, error) {
+	ctx := context.Background()
+	orgName := rd.Spec.Template.Spec.Organization
+	minReplicas := *hra.Spec.MinReplicas
+	maxReplicas := *hra.Spec.MaxReplicas
+	metrics := hra.Spec.Metrics[0]
+	scaleUpThreshold := defaultScaleUpThreshold
+	scaleDownThreshold := defaultScaleDownThreshold
+	scaleUpFactor := defaultScaleUpFactor
+	scaleDownFactor := defaultScaleDownFactor
+
+	if metrics.ScaleUpThreshold != "" {
+		sut, err := strconv.ParseFloat(metrics.ScaleUpThreshold, 64)
+		if err != nil {
+			return nil, errors.New("validating autoscaling metrics: spec.autoscaling.metrics[].scaleUpThreshold cannot be parsed into a float64")
+		}
+		scaleUpThreshold = sut
+	}
+	if metrics.ScaleDownThreshold != "" {
+		sdt, err := strconv.ParseFloat(metrics.ScaleDownThreshold, 64)
+		if err != nil {
+			return nil, errors.New("validating autoscaling metrics: spec.autoscaling.metrics[].scaleDownThreshold cannot be parsed into a float64")
+		}
+
+		scaleDownThreshold = sdt
+	}
+	if metrics.ScaleUpFactor != "" {
+		suf, err := strconv.ParseFloat(metrics.ScaleUpFactor, 64)
+		if err != nil {
+			return nil, errors.New("validating autoscaling metrics: spec.autoscaling.metrics[].scaleUpFactor cannot be parsed into a float64")
+		}
+		scaleUpFactor = suf
+	}
+	if metrics.ScaleDownFactor != "" {
+		sdf, err := strconv.ParseFloat(metrics.ScaleDownFactor, 64)
+		if err != nil {
+			return nil, errors.New("validating autoscaling metrics: spec.autoscaling.metrics[].scaleDownFactor cannot be parsed into a float64")
+		}
+		scaleDownFactor = sdf
+	}
+
+	// return the list of runners in namespace. Horizontal Runner Autoscaler should only be responsible for scaling resources in its own ns.
+	var runnerList v1alpha1.RunnerList
+	if err := r.List(ctx, &runnerList, client.InNamespace(rd.Namespace)); err != nil {
+		return nil, err
+	}
+	runnerMap := make(map[string]struct{})
+	for _, items := range runnerList.Items {
+		runnerMap[items.Name] = struct{}{}
+	}
+
+	// ListRunners will return all runners managed by GitHub - not restricted to ns
+	runners, err := r.GitHubClient.ListRunners(ctx, orgName, "")
+	if err != nil {
+		return nil, err
+	}
+	numRunners := len(runnerList.Items)
+	numRunnersBusy := 0
+	for _, runner := range runners {
+		if _, ok := runnerMap[*runner.Name]; ok && runner.GetBusy() {
+			numRunnersBusy++
+		}
+	}
+
+	var desiredReplicas int
+	fractionBusy := float64(numRunnersBusy) / float64(numRunners)
+	if fractionBusy >= scaleUpThreshold {
+		desiredReplicas = int(math.Ceil(float64(numRunners) * scaleUpFactor))
+	} else if fractionBusy < scaleDownThreshold {
+		desiredReplicas = int(float64(numRunners) * scaleDownFactor)
+	} else {
+		desiredReplicas = *rd.Spec.Replicas
+	}
+
+	if desiredReplicas < minReplicas {
+		desiredReplicas = minReplicas
+	} else if desiredReplicas > maxReplicas {
+		desiredReplicas = maxReplicas
+	}
+
+	r.Log.V(1).Info(
+		"Calculated desired replicas",
+		"computed_replicas_desired", desiredReplicas,
+		"spec_replicas_min", minReplicas,
+		"spec_replicas_max", maxReplicas,
+		"current_replicas", rd.Spec.Replicas,
+		"num_runners", numRunners,
+		"num_runners_busy", numRunnersBusy,
+	)
+
+	rd.Status.Replicas = &desiredReplicas
+	replicas := desiredReplicas
+
+	return &replicas, nil
+}

controllers/runner_controller.go

@@ -426,6 +426,9 @@ func (r *RunnerReconciler) newPod(runner v1alpha1.Runner) (corev1.Pod, error) {
 	}
 
 	if !dockerdInRunner && dockerEnabled {
+		runnerVolumeName := "runner"
+		runnerVolumeMountPath := "/runner"
+
 		pod.Spec.Volumes = []corev1.Volume{
 			{
 				Name: "work",
@@ -434,7 +437,7 @@ func (r *RunnerReconciler) newPod(runner v1alpha1.Runner) (corev1.Pod, error) {
 				},
 			},
 			{
-				Name: "externals",
+				Name: runnerVolumeName,
 				VolumeSource: corev1.VolumeSource{
 					EmptyDir: &corev1.EmptyDirVolumeSource{},
 				},
@@ -452,8 +455,8 @@ func (r *RunnerReconciler) newPod(runner v1alpha1.Runner) (corev1.Pod, error) {
 				MountPath: workDir,
 			},
 			{
-				Name:      "externals",
-				MountPath: "/runner/externals",
+				Name:      runnerVolumeName,
+				MountPath: runnerVolumeMountPath,
 			},
 			{
 				Name:      "certs-client",
@@ -484,8 +487,8 @@ func (r *RunnerReconciler) newPod(runner v1alpha1.Runner) (corev1.Pod, error) {
 					MountPath: workDir,
 				},
 				{
-					Name:      "externals",
-					MountPath: "/runner/externals",
+					Name:      runnerVolumeName,
+					MountPath: runnerVolumeMountPath,
 				},
 				{
 					Name:      "certs-client",

controllers/runnerreplicaset_controller.go

@@ -52,7 +52,7 @@ type RunnerReplicaSetReconciler struct {
 
 func (r *RunnerReplicaSetReconciler) Reconcile(req ctrl.Request) (ctrl.Result, error) {
 	ctx := context.Background()
-	log := r.Log.WithValues("runner", req.NamespacedName)
+	log := r.Log.WithValues("runnerreplicaset", req.NamespacedName)
 
 	var rs v1alpha1.RunnerReplicaSet
 	if err := r.Get(ctx, req.NamespacedName, &rs); err != nil {

github/github.go

@@ -182,7 +182,7 @@ func (c *Client) createRegistrationToken(ctx context.Context, owner, repo string
 		return c.Client.Actions.CreateRegistrationToken(ctx, owner, repo)
 	}
 
-	return CreateOrganizationRegistrationToken(ctx, c, owner)
+	return c.Client.Actions.CreateOrganizationRegistrationToken(ctx, owner)
 }
 
 func (c *Client) removeRunner(ctx context.Context, owner, repo string, runnerID int64) (*github.Response, error) {
@@ -190,7 +190,7 @@ func (c *Client) removeRunner(ctx context.Context, owner, repo string, runnerID
 		return c.Client.Actions.RemoveRunner(ctx, owner, repo, runnerID)
 	}
 
-	return RemoveOrganizationRunner(ctx, c, owner, runnerID)
+	return c.Client.Actions.RemoveOrganizationRunner(ctx, owner, runnerID)
 }
 
 func (c *Client) listRunners(ctx context.Context, owner, repo string, opts *github.ListOptions) (*github.Runners, *github.Response, error) {
@@ -198,7 +198,7 @@ func (c *Client) listRunners(ctx context.Context, owner, repo string, opts *gith
 		return c.Client.Actions.ListRunners(ctx, owner, repo, opts)
 	}
 
-	return ListOrganizationRunners(ctx, c, owner, opts)
+	return c.Client.Actions.ListOrganizationRunners(ctx, owner, opts)
 }
 
 // Validates owner and repo arguments. Both are optional, but at least one should be specified

github/github_beta.go

@@ -1,95 +0,0 @@
-package github
-
-// this contains BETA API clients, that are currently not (yet) in go-github
-// once these functions have been added there, they can be removed from here
-// code was reused from https://github.com/google/go-github
-
-import (
-	"context"
-	"fmt"
-	"net/url"
-	"reflect"
-
-	"github.com/google/go-github/v33/github"
-	"github.com/google/go-querystring/query"
-)
-
-// CreateOrganizationRegistrationToken creates a token that can be used to add a self-hosted runner on an organization.
-//
-// GitHub API docs: https://developer.github.com/v3/actions/self-hosted-runners/#create-a-registration-token-for-an-organization
-func CreateOrganizationRegistrationToken(ctx context.Context, client *Client, owner string) (*github.RegistrationToken, *github.Response, error) {
-	u := fmt.Sprintf("orgs/%v/actions/runners/registration-token", owner)
-
-	req, err := client.NewRequest("POST", u, nil)
-	if err != nil {
-		return nil, nil, err
-	}
-
-	registrationToken := new(github.RegistrationToken)
-	resp, err := client.Do(ctx, req, registrationToken)
-	if err != nil {
-		return nil, resp, err
-	}
-
-	return registrationToken, resp, nil
-}
-
-// ListOrganizationRunners lists all the self-hosted runners for an organization.
-//
-// GitHub API docs: https://developer.github.com/v3/actions/self-hosted-runners/#list-self-hosted-runners-for-an-organization
-func ListOrganizationRunners(ctx context.Context, client *Client, owner string, opts *github.ListOptions) (*github.Runners, *github.Response, error) {
-	u := fmt.Sprintf("orgs/%v/actions/runners", owner)
-	u, err := addOptions(u, opts)
-	if err != nil {
-		return nil, nil, err
-	}
-
-	req, err := client.NewRequest("GET", u, nil)
-	if err != nil {
-		return nil, nil, err
-	}
-
-	runners := &github.Runners{}
-	resp, err := client.Do(ctx, req, &runners)
-	if err != nil {
-		return nil, resp, err
-	}
-
-	return runners, resp, nil
-}
-
-// RemoveOrganizationRunner forces the removal of a self-hosted runner in a repository using the runner id.
-//
-// GitHub API docs: https://developer.github.com/v3/actions/self_hosted_runners/#remove-a-self-hosted-runner
-func RemoveOrganizationRunner(ctx context.Context, client *Client, owner string, runnerID int64) (*github.Response, error) {
-	u := fmt.Sprintf("orgs/%v/actions/runners/%v", owner, runnerID)
-
-	req, err := client.NewRequest("DELETE", u, nil)
-	if err != nil {
-		return nil, err
-	}
-
-	return client.Do(ctx, req, nil)
-}
-
-// addOptions adds the parameters in opt as URL query parameters to s. opt
-// must be a struct whose fields may contain "url" tags.
-func addOptions(s string, opts interface{}) (string, error) {
-	v := reflect.ValueOf(opts)
-	if v.Kind() == reflect.Ptr && v.IsNil() {
-		return s, nil
-	}
-
-	u, err := url.Parse(s)
-	if err != nil {
-		return s, err
-	}
-
-	qs, err := query.Values(opts)
-	if err != nil {
-		return s, err
-	}
-
-	u.RawQuery = qs.Encode()
-	return u.String(), nil
-}

runner/Dockerfile

@@ -4,6 +4,8 @@ ARG TARGETPLATFORM
 ARG RUNNER_VERSION=2.274.2
 ARG DOCKER_VERSION=19.03.12
 
+RUN test -n "$TARGETPLATFORM" || (echo "TARGETPLATFORM must be set" && false)
+
 ENV DEBIAN_FRONTEND=noninteractive
 RUN apt update -y \
   && apt install -y software-properties-common \
@@ -42,7 +44,8 @@ RUN export ARCH=$(echo ${TARGETPLATFORM} | cut -d / -f2) \
   && chmod +x /usr/local/bin/dumb-init
 
 # Docker download supports arm64 as aarch64 & amd64 as x86_64
-RUN export ARCH=$(echo ${TARGETPLATFORM} | cut -d / -f2) \
+RUN set -vx; \
+  export ARCH=$(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-${DOCKER_VERSION}.tgz \
@@ -55,6 +58,8 @@ RUN export ARCH=$(echo ${TARGETPLATFORM} | cut -d / -f2) \
   && usermod -aG docker runner \
   && echo "%sudo   ALL=(ALL:ALL) NOPASSWD:ALL" > /etc/sudoers
 
+ENV RUNNER_ASSETS_DIR=/runnertmp
+
 # Runner download supports amd64 as x64. Externalstmp is needed for making mount points work inside DinD.
 #
 # libyaml-dev is required for ruby/setup-ruby action.
@@ -62,8 +67,8 @@ RUN export ARCH=$(echo ${TARGETPLATFORM} | cut -d / -f2) \
 # to avoid rerunning apt-update on its own.
 RUN export ARCH=$(echo ${TARGETPLATFORM} | cut -d / -f2) \
   && if [ "$ARCH" = "amd64" ]; then export ARCH=x64 ; fi \
-  && mkdir -p /runner \
-  && cd /runner \
+  && mkdir -p "$RUNNER_ASSETS_DIR" \
+  && cd "$RUNNER_ASSETS_DIR" \
   && curl -L -o runner.tar.gz https://github.com/actions/runner/releases/download/v${RUNNER_VERSION}/actions-runner-linux-${ARCH}-${RUNNER_VERSION}.tar.gz \
   && tar xzf ./runner.tar.gz \
   && rm runner.tar.gz \
@@ -72,14 +77,14 @@ RUN export ARCH=$(echo ${TARGETPLATFORM} | cut -d / -f2) \
   && apt-get install -y libyaml-dev \
   && rm -rf /var/lib/apt/lists/*
 
-RUN echo AGENT_TOOLSDIRECTORY=/opt/hostedtoolcache > /runner.env \
+RUN echo AGENT_TOOLSDIRECTORY=/opt/hostedtoolcache > .env \
   && mkdir /opt/hostedtoolcache \
   && chgrp runner /opt/hostedtoolcache \
   && chmod g+rwx /opt/hostedtoolcache
 
-COPY entrypoint.sh /runner
-COPY patched /runner/patched
+COPY entrypoint.sh /
+COPY patched $RUNNER_ASSETS_DIR/patched
 
 USER runner
 ENTRYPOINT ["/usr/local/bin/dumb-init", "--"]
-CMD ["/runner/entrypoint.sh"]
+CMD ["/entrypoint.sh"]

runner/Makefile

@@ -23,15 +23,13 @@ else
 endif
 
 docker-build:
-	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 build --build-arg TARGETPLATFORM=amd64 --build-arg RUNNER_VERSION=${RUNNER_VERSION} --build-arg DOCKER_VERSION=${DOCKER_VERSION} -t ${NAME}:${TAG} .
+	docker build --build-arg TARGETPLATFORM=amd64 --build-arg RUNNER_VERSION=${RUNNER_VERSION} --build-arg DOCKER_VERSION=${DOCKER_VERSION} -t ${DIND_RUNNER_NAME}:${TAG} -f dindrunner.Dockerfile .
 
 
 docker-push:
 	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

runner/dindrunner.Dockerfile

@@ -48,6 +48,8 @@ ARG DOCKER_CHANNEL=stable
 ARG DOCKER_VERSION=19.03.13
 ARG DEBUG=false
 
+RUN test -n "$TARGETPLATFORM" || (echo "TARGETPLATFORM must be set" && false)
+
 # Docker installation
 RUN export ARCH=$(echo ${TARGETPLATFORM} | cut -d / -f2) \
     && if [ "$ARCH" = "arm64" ]; then export ARCH=aarch64 ; fi \
@@ -66,6 +68,8 @@ RUN export ARCH=$(echo ${TARGETPLATFORM} | cut -d / -f2) \
 	dockerd --version; \
 	docker --version
 
+ENV RUNNER_ASSETS_DIR=/runnertmp
+
 # Runner download supports amd64 as x64
 #
 # libyaml-dev is required for ruby/setup-ruby action.
@@ -73,8 +77,8 @@ RUN export ARCH=$(echo ${TARGETPLATFORM} | cut -d / -f2) \
 # to avoid rerunning apt-update on its own.
 RUN export ARCH=$(echo ${TARGETPLATFORM} | cut -d / -f2) \
     && if [ "$ARCH" = "amd64" ]; then export ARCH=x64 ; fi \
-    && mkdir -p /runner \
-     && cd /runner \
+    && mkdir -p "$RUNNER_ASSETS_DIR" \
+     && cd "$RUNNER_ASSETS_DIR" \
     && curl -L -o runner.tar.gz https://github.com/actions/runner/releases/download/v${RUNNER_VERSION}/actions-runner-linux-${ARCH}-${RUNNER_VERSION}.tar.gz \
     && tar xzf ./runner.tar.gz \
     && rm runner.tar.gz \
@@ -100,7 +104,7 @@ RUN export ARCH=$(echo ${TARGETPLATFORM} | cut -d / -f2) \
 
 VOLUME /var/lib/docker
 
-COPY patched /runner/patched
+COPY patched $RUNNER_ASSETS_DIR/patched
 
 # No group definition, as that makes it harder to run docker.
 USER runner

runner/entrypoint.sh

@@ -44,9 +44,18 @@ if [ -z "${RUNNER_REPO}" ] && [ -n "${RUNNER_ORG}" ] && [ -n "${RUNNER_GROUP}" ]
   RUNNER_GROUP_ARG="--runnergroup ${RUNNER_GROUP}"
 fi
 
+# Hack due to https://github.com/summerwind/actions-runner-controller/issues/252#issuecomment-758338483
+if [ ! -d /runner ]; then
+  echo "/runner should be an emptyDir mount. Please fix the pod spec." 1>&2
+  exit 1
+fi
+
+sudo chown -R runner:docker /runner
+mv /runnertmp/* /runner/
+
 cd /runner
 ./config.sh --unattended --replace --name "${RUNNER_NAME}" --url "${GITHUB_URL}${ATTACH}" --token "${RUNNER_TOKEN}" ${RUNNER_GROUP_ARG} ${LABEL_ARG} ${WORKDIR_ARG}
-
+mkdir ./externals
 # Hack due to the DinD volumes
 mv ./externalstmp/* ./externals/