CI CD Setup

CI/CD Setup

You are an expert at setting up CI/CD pipelines.

When To Use

• User says "Set up CI", "GitHub Actions"
• User asks to "Automate testing/deployment"
• New project needs CI/CD
• Adding deployment automation

Inputs

• Test command
• Build command
• Deployment target (if any)
• Branch strategy

Outputs

• .github/workflows/ci.yml
• Optional: deployment workflow
• Documentation

Basic CI Workflow

name: CI

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

jobs:
  test:
    runs-on: ubuntu-latest

    steps:
      - uses: actions/checkout@v4

      - name: Set up Python
        uses: actions/setup-python@v5
        with:
          python-version: "3.12"
          cache: "pip"

      - name: Install dependencies
        run: pip install -r requirements.txt

      - name: Run tests
        run: pytest --cov=src --cov-report=xml

      - name: Upload coverage
        uses: codecov/codecov-action@v4
        with:
          file: coverage.xml

Workflow Stages

Language-Specific Workflows

Python

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-python@v5
        with:
          python-version: "3.12"
          cache: "pip"
      - run: pip install -r requirements.txt
      - run: pytest

Node.js

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: "20"
          cache: "npm"
      - run: npm ci
      - run: npm test

Go

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-go@v5
        with:
          go-version: "1.21"
      - run: go test ./...

Full CI/CD Example

name: CI/CD

on:
  push:
    branches: [main]
    tags: ['v*']
  pull_request:
    branches: [main]

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-python@v5
        with:
          python-version: "3.12"
          cache: "pip"
      - run: pip install -r requirements.txt
      - run: pytest

  build:
    needs: test
    runs-on: ubuntu-latest
    if: github.ref == 'refs/heads/main' || startsWith(github.ref, 'refs/tags/')
    steps:
      - uses: actions/checkout@v4
      - name: Build Docker image
        run: docker build -t myapp:${{ github.sha }} .
      - name: Push to registry
        run: |
          echo ${{ secrets.DOCKER_PASSWORD }} | docker login -u ${{ secrets.DOCKER_USERNAME }} --password-stdin
          docker push myapp:${{ github.sha }}

  deploy-staging:
    needs: build
    runs-on: ubuntu-latest
    if: github.ref == 'refs/heads/main'
    environment: staging
    steps:
      - name: Deploy to staging
        run: |
          ssh user@staging "docker pull myapp:${{ github.sha }} && docker-compose up -d"

  deploy-production:
    needs: build
    runs-on: ubuntu-latest
    if: startsWith(github.ref, 'refs/tags/')
    environment: production
    steps:
      - name: Deploy to production
        run: |
          ssh user@production "docker pull myapp:${{ github.sha }} && docker-compose up -d"

Caching

pip

- uses: actions/setup-python@v5
  with:
    cache: "pip"

npm

- uses: actions/setup-node@v4
  with:
    cache: "npm"

Custom cache

- uses: actions/cache@v4
  with:
    path: ~/.cache/custom
    key: custom-${{ runner.os }}-${{ hashFiles('**/lockfile') }}

Secrets Management

steps:
  - name: Deploy
    env:
      API_KEY: ${{ secrets.API_KEY }}
    run: ./deploy.sh

Add secrets in: Settings → Secrets and variables → Actions

Branch Protection

Recommended settings:

• Require pull request reviews
• Require status checks to pass
• Require branches to be up to date
• Include administrators

Anti-Patterns

• No caching (slow builds)
• Secrets in workflow files
• No branch protection
• Missing status checks before merge
• Running tests only on main (should run on PRs)
• No environment separation

Keywords

CI, CD, GitHub Actions, pipeline, automate testing, deploy, workflow