Serverless GitHub Self-Hosted Runners

A Serverless Architecture AWS CDK application to run GitHub Actions Self-Hosted Runners in ECS Fargate

This project creates the nessasary resources in AWS to run GitHub Self-Hosted runners. More information here https://docs.github.com/en/free-pro-team@latest/actions/hosting-your-own-runners/about-self-hosted-runners

Under the hood the brilliant containerised version of actions-runner is provided by https://github.com/myoung34/docker-github-actions-runner

Getting Started

Install the dependancies for both CDK and the Lambdas:

npm install
cd src && npm install
cd ..

edit the cdk.json github_repos parameter and add the names of the repo(s) you wish to run self-hosted runners against

Build and deploy the CDK app:

npm run build
cdk deploy -c vpc_name=example.vpc.dev -c github_owner=ExampleGithubOrgName

alternatively vpc_name and github_owner can be configured in the cdk.json

Limitations

• Docker Container type actions cannot run in Fargate. Use Javascript type actions: https://docs.github.com/en/actions/creating-actions/about-actions#types-of-actions
• Docker Build, Run, etc commands cannot run in Fargate. #1 Builds may be done using a dedicated kaniko task
• Only Supports GitHub Organisation level runners. #2 Support Repository and Enterprise level runners
• Scaling up/down runners may lag by a minute as its run by a cron event. #3 An option to scale up via a webhook trigger
• The maximum number of pending/in-progress workflows per repository cannot exceed 100. #4 Implement limited pagination for octokit API call

Alternatives

• https://github.com/philips-labs/terraform-aws-github-runner
• https://github.com/intercept6/aws-cdk-actions-self-hosted