How to Lint YAML with yamllint in GitHub Actions

YAML is whitespace-sensitive and unforgiving; yamllint turns a silent indentation bug into a clear CI failure.

Run yamllint across the repo with a tuned config so structural and style issues fail the job.

Steps

• Install yamllint with pip.
• Add a .yamllint config to relax rules like line length where appropriate.
• Run yamllint . and let failures fail the build.

Workflow

name: yamllint
on: [pull_request]
jobs:
  yamllint:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-python@v5
        with:
          python-version: '3.12'
      - run: pip install yamllint
      - run: yamllint -c .yamllint .

Notes

• Relax line-length in .yamllint so long URLs in config do not fail the lint.
• On Latchkey managed runners YAML lint jobs run cheaper and self-heal if a runner dies.

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