Concourse GitHub Commit Resource

A Concourse resource type for GitHub commits.

The check script detects new commits on any branch on a GitHub repository. This includes commits for work-in-progress branches, but does not include commits on any other GitHub repository, such as forks.

The in script (used in get steps) creates several files corresponding to a single commit on any branch of a GitHub repository:

• ref contains the sha of the commit
• author contains the name of the committer from GitHub's API
• message contains the commit message from GitHub's API
• state contains the current combined status of the commit, if any
• repo contains the pulled repository checked out at the specified commit
• combined_status contains the full combined_status JSON from GitHub's API
• commit contains the full commit JSON from GitHub's API

These files should be sufficient to replace some workflows for the popular git resource provided by Concourse.

The out script (used in put steps) allows one to add a status to a commit in GitHub. For example, you might add a "pending" status at the beginning of a build or test run and add a "success" step at the end of the build.

The following example runs tests for every new commit, and updates the status for a check on a GitHub commit (pending, and then success/failure/error).

resource_types:
  - name: github-commit
    type: registry-image
    source:
      repository: govuk/github-commit

resources:
  - name: commit
    type: github-commit
    source:
      repository: alphagov/frontend
      access_token: ((github_access_token))
      path: commit # relative path to the commit, must match the resource name.

jobs:
  - name: run-tests
    plan:
    - get: github-commit
      trigger: true
    - put: github-commit
      params:
        context: run-tests # corresponds to GitHub Status API context field
        status: pending # puts a pending status on the GitHub commit
    - task: run-tests
      file: repo/run-tests.yml
    on_success:
      put: commit
      params: {status: success, context: run-tests} # puts a success status on the GitHub commit
    on_failure:
      put: commit
      params: {status: failure, context: run-tests}
    on_abort:
      put: commit
      params: {status: error, context: run-tests}
    on_error:
      put: commit
      params: {status: error, context: run-tests}

The output of this project is a container image pushed to DockerHub, for use in Concourse pipelines as a Resource Type.

Read Implementing a Resource Type for an understanding of how this project fits into a Concourse pipeline.

Tests for this project run in GitHub Actions, but can also be run locally:

bundle exec rubocop
bundle exec rspec

Concourse pipelines pull the resource type as a Docker image; we also publish the lib part of the project as a gem.

Please consider incrementing the version when making a change. Both artefacts are version-controlled by the VERSION file, which is used by a Concourse pipeline that publishes the artefacts to RubyGems.org and DockerHub.

• DockerHub: https://hub.docker.com/r/govuk/github-commit
• RubyGems: https://rubygems.org/gems/github_commit