GitHub API

The GitHub CLI¹ (gh) is a command-line interface to GitHub right from your terminal. Anything the gh CLI can do, you can do with it in GitHub Actions – it is pre-installed on all runners.

Let’s try automatically adding an issue comment when a label is added to the issue.²

.github/workflows/add-comment.yml

name: Add comment

1on:
  issues:
    types:
      - labeled

jobs:
  add-comment:
2    if: github.event.label.name == 'help wanted'
    runs-on: ubuntu-latest
    permissions:
      issues: write
    steps:
3      - name: Add comment
        run: gh issue comment "$NUMBER" --body "$BODY"
        env:
4          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
5          GH_REPO: ${{ github.repository }}
6          NUMBER: ${{ github.event.issue.number }}
7          BODY: >
            This issue is available for anyone to work on.
            **Make sure to reference this issue in your pull request.**
            :sparkles: Thank you for your contribution! :sparkles:

1: Run this workflow when an issue is labeled.
2: Only run this job if the issues was labeled with “help wanted”.
3: Use the gh cli to add a comment to the issue. $NUMBER and $BODY are filled in from the environment variables specified by env.
4: Set the GH_TOKEN environment variable to the default GITHUB_TOKEN secret³, which is automatically created by GitHub for each workflow run. This token is used by the gh CLI to authenticate and comment on the issue. Permissions are limited by default⁴.
5: The name of this repo, which is a required environment variable for gh CLI⁵.
6: The issue number from the event that triggered this workflow run.
7: The body of the comment to add. Use markdown syntax just like you would if you were typing an issue comment through the web interface.

Create an issue in your repo and add the “help wanted” label. Go the the Actions tab and see if the workflow is running. Once it completes, go back to your issue – did it create the comment like you expected?

Peruse the GitHub CLI manual. What other processes could you automate for managing issues, PRs, and projects?

Footnotes

GitHub CLI manual https://cli.github.com/manual/↩︎
This action was adapted from https://docs.github.com/en/actions/use-cases-and-examples/project-management/commenting-on-an-issue-when-a-label-is-added ↩︎
GITHUB_TOKEN https://docs.github.com/en/actions/security-for-github-actions/security-guides/automatic-token-authentication ↩︎
Default permissions for GITHUB_TOKEN https://docs.github.com/en/actions/security-for-github-actions/security-guides/automatic-token-authentication#permissions-for-the-github_token ↩︎
Environment variables needed by gh cli https://cli.github.com/manual/gh_help_environment ↩︎