Simple YAML Linter/Validator Workflow for GitHub Actions

Here's a quick tip if you work with YAML on GitHub!

The GitHub Actions Ubuntu runners comes with yamllint installed, meaning it's super simple to create linting/validating workflows to ensure your YAML is valid!

name: Validate YAML

on:
  push:
  pull_request:

jobs:
  validate-yaml:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - name: Validate YAML file
        run: yamllint my-file.yml

Comments

[Ismael Hommani]

And one day it is not available anymore ^^.
I'd rather be explicit about the dependency you need rather than relying on "by conincedence" installed tools on the runner.
Consider your pipeline as an application. Follow the factor II from 12 factors: 12factor.net/dependencies

[CodeWithCaen]

Is it no longer available, or are you speaking generally?

[Ismael Hommani]

Generally but it happens to me once for a different tool.

[Ismael Hommani]

For instance, even if it works rightaway on the runner I avoid to do that:

jobs:
  format_github_action_files:
    runs-on: ubuntu-22.04
    steps:
      - name: Check out repository
        uses: actions/checkout@v4

      - name: format gha files'
        id: gha_fmt
        run: yamlfmt ${{ inputs.gha_definition_files_folder }}

but rather do that:

jobs:
  format_github_action_files:
    runs-on: ubuntu-22.04
    steps:
      - name: Check out repository
        uses: actions/checkout@v4

      - uses: actions/setup-go@v5
        with:
          go-version: '>=1.17.0'

      - name: install yamlfmt
        id: yamlfmt_install
        run: go install github.com/google/yamlfmt/cmd/yamlfmt@latest

      - name: format gha files'
        id: gha_fmt
        run: |-
          yamlfmt ${{ inputs.gha_definition_files_folder }}