GitHub Actions Core Knowledge

Deep Knowledge: Use mcp__documentation__fetch_docs with technology: github-actions for comprehensive documentation.

Basic CI Workflow

# .github/workflows/ci.yml
name: CI

on:
  push:
    branches: [main]
  pull_request:
    branches: [main]

jobs:
  test:
    runs-on: ubuntu-latest

    steps:
      - uses: actions/checkout@v4

      - name: Setup Node.js
        uses: actions/setup-node@v4
        with:
          node-version: '20'
          cache: 'npm'

      - name: Install dependencies
        run: npm ci

      - name: Run linter
        run: npm run lint

      - name: Run tests
        run: npm test

      - name: Build
        run: npm run build

With Database

jobs:
  test:
    runs-on: ubuntu-latest

    services:
      postgres:
        image: postgres:16
        env:
          POSTGRES_USER: test
          POSTGRES_PASSWORD: test
          POSTGRES_DB: testdb
        ports:
          - 5432:5432
        options: >-
          --health-cmd pg_isready
          --health-interval 10s
          --health-timeout 5s
          --health-retries 5

    env:
      DATABASE_URL: postgresql://test:test@localhost:5432/testdb

    steps:
      - uses: actions/checkout@v4
      - run: npm ci
      - run: npx prisma migrate deploy
      - run: npm test

Deploy Workflow

name: Deploy

on:
  push:
    branches: [main]

jobs:
  deploy:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - name: Deploy to Vercel
        uses: amondnet/vercel-action@v25
        with:
          vercel-token: ${{ secrets.VERCEL_TOKEN }}
          vercel-org-id: ${{ secrets.VERCEL_ORG_ID }}
          vercel-project-id: ${{ secrets.VERCEL_PROJECT_ID }}
          vercel-args: '--prod'

Matrix Strategy

jobs:
  test:
    strategy:
      matrix:
        node: [18, 20, 22]
        os: [ubuntu-latest, macos-latest]
    runs-on: ${{ matrix.os }}
    steps:
      - uses: actions/setup-node@v4
        with:
          node-version: ${{ matrix.node }}

Reusable Workflows

# .github/workflows/test.yml
on:
  workflow_call:

jobs:
  test:
    runs-on: ubuntu-latest
    steps: [...]

# Usage in another workflow
jobs:
  call-tests:
    uses: ./.github/workflows/test.yml

When NOT to Use This Skill

Skip this skill when:

• Using GitLab CI/CD (.gitlab-ci.yml) - different syntax
• Using Jenkins, CircleCI, Travis CI - different platforms
• Setting up local development environments - use docker-compose skill
• Building Docker images only (no CI needed) - use docker skill
• Working with Bitbucket Pipelines - different platform

Anti-Patterns

Quick Troubleshooting

Production Readiness

Security Best Practices

# Secure workflow
name: CI

on:
  push:
    branches: [main]
  pull_request:
    branches: [main]

permissions:
  contents: read
  pull-requests: write

jobs:
  build:
    runs-on: ubuntu-latest
    timeout-minutes: 15

    steps:
      - uses: actions/checkout@v4
        with:
          persist-credentials: false

      # Pin actions to SHA for security
      - uses: actions/setup-node@60edb5dd545a775178f52524783378180af0d1f8 # v4.0.2
        with:
          node-version: '20'

      # Use environment secrets
      - name: Deploy
        env:
          API_KEY: ${{ secrets.API_KEY }}
        run: |
          # Never echo secrets
          ./deploy.sh

Caching Strategy

jobs:
  build:
    steps:
      - uses: actions/checkout@v4

      - uses: actions/setup-node@v4
        with:
          node-version: '20'
          cache: 'npm'

      # Custom caching
      - name: Cache dependencies
        uses: actions/cache@v4
        with:
          path: |
            ~/.npm
            node_modules
          key: ${{ runner.os }}-node-${{ hashFiles('**/package-lock.json') }}
          restore-keys: |
            ${{ runner.os }}-node-

      # Turbo cache for monorepos
      - name: Cache Turbo
        uses: actions/cache@v4
        with:
          path: .turbo
          key: ${{ runner.os }}-turbo-${{ github.sha }}
          restore-keys: |
            ${{ runner.os }}-turbo-

Artifact Management

jobs:
  build:
    steps:
      - name: Build
        run: npm run build

      - name: Upload build artifacts
        uses: actions/upload-artifact@v4
        with:
          name: build-${{ github.sha }}
          path: dist/
          retention-days: 7

  deploy:
    needs: build
    steps:
      - name: Download artifacts
        uses: actions/download-artifact@v4
        with:
          name: build-${{ github.sha }}
          path: dist/

Environment Protection

jobs:
  deploy-staging:
    runs-on: ubuntu-latest
    environment: staging

  deploy-production:
    runs-on: ubuntu-latest
    needs: deploy-staging
    environment:
      name: production
      url: https://example.com
    concurrency:
      group: production-deploy
      cancel-in-progress: false

Error Handling

jobs:
  build:
    steps:
      - name: Run tests
        id: tests
        continue-on-error: true
        run: npm test

      - name: Upload test results
        if: always()
        uses: actions/upload-artifact@v4
        with:
          name: test-results
          path: coverage/

      - name: Check test status
        if: steps.tests.outcome == 'failure'
        run: |
          echo "Tests failed"
          exit 1

      - name: Notify on failure
        if: failure()
        uses: slackapi/slack-github-action@v1
        with:
          payload: |
            {"text": "Build failed: ${{ github.repository }}"}
        env:
          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK }}

Dependabot Configuration

# .github/dependabot.yml
version: 2
updates:
  - package-ecosystem: "npm"
    directory: "/"
    schedule:
      interval: "weekly"
    groups:
      development-dependencies:
        patterns:
          - "@types/*"
          - "eslint*"
          - "prettier*"

  - package-ecosystem: "github-actions"
    directory: "/"
    schedule:
      interval: "weekly"

Release Workflow

name: Release

on:
  push:
    tags:
      - 'v*'

jobs:
  release:
    runs-on: ubuntu-latest
    permissions:
      contents: write

    steps:
      - uses: actions/checkout@v4

      - name: Build
        run: npm run build

      - name: Create Release
        uses: softprops/action-gh-release@v2
        with:
          files: dist/*
          generate_release_notes: true

Monitoring Metrics

Checklist

• Minimal permissions declared
• Actions pinned to SHA
• Secrets not exposed in logs
• Caching configured
• Timeouts set
• Error notifications
• Environment protection rules
• Dependabot enabled
• Branch protection rules
• Concurrency controls

Reference Documentation

• Caching
• Secrets