Post coverage comment workflow (django-commons/django-unicorn)

The Post coverage comment workflow from django-commons/django-unicorn, explained and optimized by Latchkey.

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Source: django-commons/django-unicorn.github/workflows/coverage.ymlLicense MITView source

What it does

This is the Post coverage comment workflow from the django-commons/django-unicorn repository, a real project running GitHub Actions. It is shown here with attribution under its MIT license.

Below, Latchkey shows a faster, safer version produced by its optimization engine.

The workflow

workflow (.yml)

name: Post coverage comment

on:
  workflow_run:
    workflows: ["CI"]
    types:
      - completed

jobs:
  test:
    name: Run tests & display coverage
    runs-on: ubuntu-latest
    if: github.event.workflow_run.event == 'pull_request' && github.event.workflow_run.conclusion == 'success'
    permissions:
      # Gives the action the necessary permissions for publishing new
      # comments in pull requests.
      pull-requests: write
      # Gives the action the necessary permissions for editing existing
      # comments (to avoid publishing multiple comments in the same PR)
      contents: write
      # Gives the action the necessary permissions for looking up the
      # workflow that launched this workflow, and download the related
      # artifact that contains the comment to be published
      actions: read
    steps:
      # DO NOT run actions/checkout here, for security reasons
      # For details, refer to https://securitylab.github.com/research/github-actions-preventing-pwn-requests/
      - name: Post comment
        uses: py-cov-action/python-coverage-comment-action@v3
        with:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          GITHUB_PR_RUN_ID: ${{ github.event.workflow_run.id }}
          # Update those if you changed the default values:
          # COMMENT_ARTIFACT_NAME: python-coverage-comment-action
          # COMMENT_FILENAME: python-coverage-comment-action.txt

The same workflow, on Latchkey

Removes redundant runs and caps runaway jobs. Added and changed lines are highlighted.

name: Post coverage comment
 
on:
  workflow_run:
    workflows: ["CI"]
    types:
      - completed
 
jobs:
  test:
    timeout-minutes: 30
    name: Run tests & display coverage
    runs-on: latchkey-small
    if: github.event.workflow_run.event == 'pull_request' && github.event.workflow_run.conclusion == 'success'
    permissions:
      # Gives the action the necessary permissions for publishing new
      # comments in pull requests.
      pull-requests: write
      # Gives the action the necessary permissions for editing existing
      # comments (to avoid publishing multiple comments in the same PR)
      contents: write
      # Gives the action the necessary permissions for looking up the
      # workflow that launched this workflow, and download the related
      # artifact that contains the comment to be published
      actions: read
    steps:
      # DO NOT run actions/checkout here, for security reasons
      # For details, refer to https://securitylab.github.com/research/github-actions-preventing-pwn-requests/
      - name: Post comment
        uses: py-cov-action/python-coverage-comment-action@v3
        with:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          GITHUB_PR_RUN_ID: ${{ github.event.workflow_run.id }}
          # Update those if you changed the default values:
          # COMMENT_ARTIFACT_NAME: python-coverage-comment-action
          # COMMENT_FILENAME: python-coverage-comment-action.txt

What changed

Run on Latchkey managed runners with one line (runs-on), which apply the fixes below automatically and self-heal transient failures. This example uses latchkey-small; pick the runner size that fits the job.
Add a job timeout so a hung step cannot burn hours of runner time.

1 third-party action is referenced by a movable tag. Pin it to the commit SHA (Latchkey resolves and applies this automatically) so a repointed tag cannot change what runs.

This workflow runs 1 job per trigger. On Latchkey the same minutes cost up to 58% less than GitHub-hosted, with zero queue time.