CI Workflow Validation Skill

Validate GitHub Actions workflow files.

When to Use

• Creating new workflow
• Modifying existing workflow
• Workflow syntax errors
• Before committing workflow changes

Validation Methods

1. GitHub CLI

# View workflow
gh workflow view <workflow-name>

# List workflows
gh workflow list

# Check workflow syntax (via API)
gh api repos/{owner}/{repo}/actions/workflows

2. actionlint

# Install
pip install actionlint

# Validate workflows
actionlint .github/workflows/*.yml

3. yamllint

# Validate YAML syntax
yamllint .github/workflows/*.yml

Common Issues

1. Syntax Errors

# ❌ Wrong
on: [push pull_request]

# ✅ Correct
on: [push, pull_request]

2. Invalid Actions

# ❌ Wrong version
- uses: actions/checkout@v99

# ✅ Correct
- uses: actions/checkout@v4

3. Missing Required Fields

# ❌ Missing 'runs-on'
jobs:
  test:
    steps:
      - run: echo "test"

# ✅ Complete
jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - run: echo "test"

Best Practices

• Use specific action versions (@v4, not @main)
• Pin to commit SHA for security
• Use if conditions to save CI time
• Set explicit timeouts
• Cache dependencies

Example:

jobs:
  test:
    runs-on: ubuntu-latest
    timeout-minutes: 10
    steps:
      - uses: actions/checkout@v4
      - uses: actions/cache@v3
        with:
          path: ~/.cache/pip
          key: ${{ runner.os }}-pip-${{ hashFiles('**/requirements.txt') }}

See GitHub Actions documentation for complete reference.