Github org runner exporter

Prometheus metrics exporter for GitHub actions self-hosted runners.

Settings

Variable	Required	Description
PRIVATE_GITHUB_TOKEN	Yes	Github token with read org permissions
OWNER	Yes	Github organization name
REFRESH_INTERVAL	No	Internval time in seconds betwen api requests (Default: 20)
LOG_LEVEL	No	Log level: DEBUG, INFO, WARNING or ERROR (Default: INFO)

Authenticating with Github App

The runner exporter requires an API authentication, the recommended way is to create a Github App from the Organization Settings with read-only permission for Self-hosted runners, after creating the App you have to install it to the Organization.

You can create the app from the link https://github.com/organizations/MYORG/settings/apps

Variable	Required	Description
GITHUB_APP_ID	Yes	Github App ID
GITHUB_PRIVATE_KEY	Yes	Github App private key, you can generate a
API_URL	No	URL to your github API, for Github Enterprise, set it with your API url, like https://github.myenterprise.com/api/v3/orgs/MYORG/ (Default: https://api.github.com)

Authenticating with a Private Token

It’s also possible to authenticate using a Private user token, but it’s not recommended.

Variable	Required	Description
PRIVATE_GITHUB_TOKEN	Yes	Github token with read org permissions

How to deploy

Once you have created the Github APP, installed it and downloaded the private key file, you can generate a Kubernetes secrets to store it, like:

kubectl create secret generic runner-exporter \
        --from-literal=OWNER=organization_name \
        --from-literal=GITHUB_APP_ID=app_id \
        --from-literal=GITHUB_PRIVATE_KEY="-----KEY-----
xxxxxxxx
xxxxxxxx
xxxxxxxx
-----END KEY-----"

Add the helm repo:

helm repo add tchelovilar https://tchelovilar.github.io/github-org-runner-exporter/
helm repo update

Install the helm chart:

helm install github-runner-exporter --set envFromSecret=runner-exporter tchelovilar/prometheus-org-runner-exporter

Grafana Dashboard

Import the grafana dashboard file grafana/dashboard.json

Runners Auto Scaling

The generated metrics can be used by Keda to scale up the Github Runners, on this example keda will add an extra pod when the number of Pods is the same of active replicas. Be careful, the auto scaler will always scale down the most recent pod, which can interrupt long-running jobs, be sure that you have the Github Runners properly configured to proceed with the scale-down.

apiVersion: keda.sh/v1alpha1
kind: ScaledObject
metadata:
  name: github-runner
spec:
  advanced:
    horizontalPodAutoscalerConfig:
      behavior:
        scaleDown:
          policies:
          - periodSeconds: 15
            type: Percent
            value: 100
          stabilizationWindowSeconds: 1800 # Seconds before start to scale down
  maxReplicaCount: 8
  minReplicaCount: 1
  scaleTargetRef:
    kind: Deployment
    name: github-runner # Kubernetes Deployment name
  triggers:
  - metadata:
      query: sum(github_runner_org_busy{busy="true", labels="docker,scale"})
      serverAddress: http://prometheus-server.prometheus.svc.cluster.local:9090  # Prometheus server address
      threshold: "0.9"
    type: prometheus