GitHub Actions: CI/CD Pipeline einfach erklärt

GitHub Actions: CI/CD für Einsteiger

GitHub Actions automatisiert Ihren gesamten Software-Entwicklungsprozess. Builds, Tests, Deployments – alles direkt in GitHub. Diese Anleitung zeigt Ihnen den Einstieg.

Was ist CI/CD?

Continuous Integration (CI): Automatisches Bauen und Testen bei jedem Push.

Continuous Deployment (CD): Automatisches Deployment nach erfolgreichem Test.

Vorteile:

• Fehler früh erkennen
• Konsistente Builds
• Schnellere Releases
• Weniger manuelle Arbeit

Ihr erster Workflow

Erstellen Sie .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 tests
        run: npm test

Was passiert hier?

• Trigger bei Push und Pull Request auf main
• Ubuntu-Runner wird gestartet
• Repository wird ausgecheckt
• Node.js wird installiert
• Dependencies werden installiert
• Tests werden ausgeführt

Workflow-Syntax verstehen

Trigger (on)

on:
  # Bei jedem Push
  push:

  # Nur bestimmte Branches
  push:
    branches: [main, develop]

  # Bei Tags
  push:
    tags: ['v*']

  # Pull Requests
  pull_request:
    branches: [main]

  # Zeitgesteuert (Cron)
  schedule:
    - cron: '0 0 * * *'  # Täglich um Mitternacht

  # Manuell auslösbar
  workflow_dispatch:

  # Bei Release
  release:
    types: [published]

Jobs und Steps

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - name: Step 1
        run: echo "Hello"

  test:
    runs-on: ubuntu-latest
    needs: build  # Wartet auf build
    steps:
      - name: Step 1
        run: echo "Testing"

  deploy:
    runs-on: ubuntu-latest
    needs: [build, test]  # Wartet auf beide
    if: github.ref == 'refs/heads/main'
    steps:
      - name: Deploy
        run: echo "Deploying"

Praxisbeispiele

Node.js Projekt mit Tests

name: Node.js CI

on:
  push:
    branches: [main]
  pull_request:

jobs:
  test:
    runs-on: ubuntu-latest

    strategy:
      matrix:
        node-version: [18, 20, 22]

    steps:
      - uses: actions/checkout@v4

      - name: Use Node.js ${{ matrix.node-version }}
        uses: actions/setup-node@v4
        with:
          node-version: ${{ matrix.node-version }}
          cache: 'npm'

      - run: npm ci
      - run: npm run build --if-present
      - run: npm test

  lint:
    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 run lint

Python mit pytest

name: Python CI

on: [push, pull_request]

jobs:
  test:
    runs-on: ubuntu-latest

    steps:
      - uses: actions/checkout@v4

      - name: Set up Python
        uses: actions/setup-python@v5
        with:
          python-version: '3.11'
          cache: 'pip'

      - name: Install dependencies
        run: |
          python -m pip install --upgrade pip
          pip install -r requirements.txt
          pip install pytest pytest-cov

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

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

Docker Build und Push

name: Docker

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

jobs:
  build:
    runs-on: ubuntu-latest

    steps:
      - uses: actions/checkout@v4

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3

      - name: Login to Docker Hub
        uses: docker/login-action@v3
        with:
          username: ${{ secrets.DOCKER_USERNAME }}
          password: ${{ secrets.DOCKER_PASSWORD }}

      - name: Build and push
        uses: docker/build-push-action@v5
        with:
          context: .
          push: true
          tags: |
            username/app:latest
            username/app:${{ github.sha }}
          cache-from: type=gha
          cache-to: type=gha,mode=max

Deployment zu Vercel

name: Deploy to Vercel

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'

Deployment zu Server via SSH

name: Deploy to Server

on:
  push:
    branches: [main]

jobs:
  deploy:
    runs-on: ubuntu-latest

    steps:
      - uses: actions/checkout@v4

      - name: Deploy via SSH
        uses: appleboy/ssh-action@v1.0.0
        with:
          host: ${{ secrets.SERVER_HOST }}
          username: ${{ secrets.SERVER_USER }}
          key: ${{ secrets.SSH_PRIVATE_KEY }}
          script: |
            cd /var/www/app
            git pull origin main
            npm ci
            npm run build
            pm2 restart app

Secrets und Umgebungsvariablen

Secrets einrichten

Repository → Settings → Secrets and variables → Actions → New repository secret

Secrets verwenden

steps:
  - name: Use secret
    env:
      API_KEY: ${{ secrets.API_KEY }}
    run: |
      curl -H "Authorization: Bearer $API_KEY" https://api.example.com

Umgebungsspezifische Secrets

jobs:
  deploy:
    runs-on: ubuntu-latest
    environment: production  # Nutzt production-Secrets

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

Caching für schnellere Builds

npm Cache

- uses: actions/setup-node@v4
  with:
    node-version: '20'
    cache: 'npm'  # Automatisches Caching!

Manuelles Caching

- name: Cache dependencies
  uses: actions/cache@v4
  with:
    path: ~/.cache/pip
    key: ${{ runner.os }}-pip-${{ hashFiles('requirements.txt') }}
    restore-keys: |
      ${{ runner.os }}-pip-

Artifacts speichern

Build-Artifacts hochladen

- name: Build
  run: npm run build

- name: Upload artifact
  uses: actions/upload-artifact@v4
  with:
    name: build
    path: dist/
    retention-days: 5

Artifacts in anderem Job nutzen

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - run: npm run build
      - uses: actions/upload-artifact@v4
        with:
          name: build
          path: dist/

  deploy:
    needs: build
    runs-on: ubuntu-latest
    steps:
      - uses: actions/download-artifact@v4
        with:
          name: build
          path: dist/
      - run: ./deploy.sh

Matrix Builds

Testen Sie auf mehreren Plattformen/Versionen gleichzeitig:

jobs:
  test:
    runs-on: ${{ matrix.os }}

    strategy:
      matrix:
        os: [ubuntu-latest, windows-latest, macos-latest]
        node: [18, 20, 22]
        exclude:
          - os: macos-latest
            node: 18

    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: ${{ matrix.node }}
      - run: npm test

Bedingte Ausführung

jobs:
  deploy:
    if: github.event_name == 'push' && github.ref == 'refs/heads/main'

  notify:
    if: failure()  # Nur bei Fehler
    needs: [build, test]

Wiederverwendbare Workflows

Workflow definieren

# .github/workflows/reusable-test.yml
name: Reusable Test Workflow

on:
  workflow_call:
    inputs:
      node-version:
        required: true
        type: string

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: ${{ inputs.node-version }}
      - run: npm ci && npm test

Workflow aufrufen

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

on: [push]

jobs:
  test:
    uses: ./.github/workflows/reusable-test.yml
    with:
      node-version: '20'

Fehlersuche und Debugging

Debug-Logging aktivieren

Repository → Settings → Secrets → Add:

• ACTIONS_RUNNER_DEBUG = true
• ACTIONS_STEP_DEBUG = true

Lokales Testen mit act

# act installieren (macOS)
brew install act

# Workflow lokal ausführen
act push

Best Practices

1. Caching nutzen – Spart Build-Zeit
2. Secrets nie hart codieren – Immer Repository Secrets
3. Concurrency limitieren – Verhindert parallele Deployments
4. Timeout setzen – Hängende Jobs stoppen
5. Spezifische Versionen – @v4 statt @latest

jobs:
  deploy:
    runs-on: ubuntu-latest
    timeout-minutes: 10
    concurrency:
      group: production
      cancel-in-progress: false

Fazit

GitHub Actions ist ein mächtiges CI/CD-Tool, das direkt in GitHub integriert ist. Starten Sie mit einfachen Workflows und erweitern Sie schrittweise.

Bei komplexeren DevOps-Anforderungen unterstützt Balane Tech Sie gerne bei der Einrichtung professioneller CI/CD-Pipelines.