← YAML Index

⚙️ YAML in DevOps — Kubernetes, Docker Compose, Ansible, GitHub Actions

📋 Reference

💡 Example

# ── Kubernetes Deployment ────────────────────────────────────
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: mywebuniversity-api
  namespace: production
  labels:
    app: mywebuniversity
    tier: backend
    version: "2.0"
spec:
  replicas: 3
  selector:
    matchLabels:
      app: mywebuniversity
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxSurge: 1
      maxUnavailable: 0
  template:
    metadata:
      labels:
        app: mywebuniversity
        tier: backend
    spec:
      containers:
        - name: api
          image: mywebuniversity/api:2.0.1
          ports:
            - containerPort: 8080
          env:
            - name: NODE_ENV
              value: production
            - name: DB_PASSWORD
              valueFrom:
                secretKeyRef:
                  name: db-secret
                  key: password
            - name: REDIS_URL
              valueFrom:
                configMapKeyRef:
                  name: app-config
                  key: redis_url
          resources:
            requests:
              cpu:    "100m"
              memory: "128Mi"
            limits:
              cpu:    "500m"
              memory: "512Mi"
          livenessProbe:
            httpGet:
              path: /health
              port: 8080
            initialDelaySeconds: 10
            periodSeconds: 30
          readinessProbe:
            httpGet:
              path: /ready
              port: 8080
            initialDelaySeconds: 5
            periodSeconds: 10
---
# ── Docker Compose ───────────────────────────────────────────
services:
  api:
    build:
      context: .
      dockerfile: Dockerfile
      args:
        NODE_VERSION: "20"
    image: mywebuniversity/api:latest
    ports:
      - "3000:3000"
    environment:
      NODE_ENV:    development
      DB_HOST:     db
      REDIS_HOST:  cache
    volumes:
      - ./src:/app/src
      - /app/node_modules
    depends_on:
      db:
        condition: service_healthy
      cache:
        condition: service_started
    restart: unless-stopped

  db:
    image: postgres:16-alpine
    environment:
      POSTGRES_DB:       mywebuniversity
      POSTGRES_USER:     admin
      POSTGRES_PASSWORD: ${DB_PASSWORD}
    volumes:
      - postgres_data:/var/lib/postgresql/data
      - ./init.sql:/docker-entrypoint-initdb.d/init.sql
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U admin -d mywebuniversity"]
      interval: 10s
      timeout:  5s
      retries:  5

  cache:
    image: redis:7-alpine
    command: redis-server --maxmemory 256mb --maxmemory-policy allkeys-lru

volumes:
  postgres_data:
---
# ── GitHub Actions CI/CD ─────────────────────────────────────
name: CI/CD Pipeline

on:
  push:
    branches: [main, develop]
  pull_request:
    branches: [main]
  schedule:
    - cron: '0 6 * * 1'   # Every Monday at 6am UTC

jobs:
  test:
    runs-on: ubuntu-latest
    strategy:
      matrix:
        python-version: ['3.10', '3.11', '3.12']
        os: [ubuntu-latest, macos-latest]
    steps:
      - uses: actions/checkout@v4
      - name: Set up Python ${{ matrix.python-version }}
        uses: actions/setup-python@v5
        with:
          python-version: ${{ matrix.python-version }}
      - name: Install dependencies
        run: |
          pip install -r requirements.txt
          pip install pytest pytest-cov
      - name: Run tests
        run: pytest --cov=. --cov-report=xml
      - name: Upload coverage
        uses: codecov/codecov-action@v4

  deploy:
    needs: test
    runs-on: ubuntu-latest
    if: github.ref == 'refs/heads/main'
    steps:
      - uses: actions/checkout@v4
      - name: Deploy to production
        env:
          SSH_KEY: ${{ secrets.DEPLOY_SSH_KEY }}
        run: |
          echo "$SSH_KEY" > /tmp/deploy_key
          chmod 600 /tmp/deploy_key
          ssh -i /tmp/deploy_key deploy@mywebuniversity.com \
            'cd /app && git pull && systemctl restart api'
---
# ── Ansible Playbook ─────────────────────────────────────────
---
- name: Configure MyWebUniversity web server
  hosts: webservers
  become: true
  vars:
    app_user:  www-data
    app_dir:   /var/www/React/prod
    node_ver:  "20"
  vars_files:
    - vars/secrets.yml

  pre_tasks:
    - name: Update apt cache
      apt:
        update_cache: true
        cache_valid_time: 3600

  tasks:
    - name: Install system packages
      apt:
        name:
          - apache2
          - python3
          - python3-pip
          - git
        state: present

    - name: Enable Apache CGI module
      apache2_module:
        name: cgid
        state: present
      notify: Restart Apache

    - name: Deploy application files
      copy:
        src:   "{{ item }}"
        dest:  "{{ app_dir }}/"
        owner: "{{ app_user }}"
        mode:  "0644"
      with_fileglob:
        - files/*.html
      notify: Reload Apache

    - name: Deploy CGI scripts
      copy:
        src:   cgi-bin/
        dest:  /usr/lib/cgi-bin/
        owner: "{{ app_user }}"
        mode:  "0755"

  handlers:
    - name: Restart Apache
      service:
        name:  apache2
        state: restarted

    - name: Reload Apache
      service:
        name:  apache2
        state: reloaded

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