Modern DevOps: Building Robust CI/CD Pipelines for Cloud-Native Applications

# .github/workflows/ci-cd.yml
name: CI/CD Pipeline

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

env:
  REGISTRY: ghcr.io
  IMAGE_NAME: ${{ github.repository }}

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

      - name: Set up 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 -- --coverage

      - name: Upload coverage
        uses: codecov/codecov-action@v3

  security-scan:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - name: Run Snyk security scan
        uses: snyk/actions/node@master
        env:
          SNYK_TOKEN: ${{ secrets.SNYK_TOKEN }}

      - name: Run Trivy vulnerability scanner
        uses: aquasecurity/trivy-action@master
        with:
          scan-type: 'fs'
          scan-ref: '.'

  build:
    needs: [test, security-scan]
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write

    steps:
      - uses: actions/checkout@v4

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

      - name: Log in to Container Registry
        uses: docker/login-action@v3
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Extract metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
          tags: |
            type=sha,prefix={{branch}}-
            type=ref,event=branch
            type=semver,pattern={{version}}

      - name: Build and push Docker image
        uses: docker/build-push-action@v5
        with:
          context: .
          push: true
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=gha
          cache-to: type=gha,mode=max

  deploy-staging:
    needs: build
    if: github.ref == 'refs/heads/develop'
    runs-on: ubuntu-latest
    environment: staging

    steps:
      - uses: actions/checkout@v4

      - name: Configure AWS credentials
        uses: aws-actions/configure-aws-credentials@v4
        with:
          aws-access-key-id: ${{ secrets.AWS_ACCESS_KEY_ID }}
          aws-secret-access-key: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
          aws-region: us-east-1

      - name: Update kubeconfig
        run: |
          aws eks update-kubeconfig --name staging-cluster --region us-east-1

      - name: Deploy to Kubernetes
        run: |
          kubectl set image deployment/myapp             myapp=${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:develop             -n staging
          kubectl rollout status deployment/myapp -n staging

  deploy-production:
    needs: build
    if: github.ref == 'refs/heads/main'
    runs-on: ubuntu-latest
    environment:
      name: production
      url: https://app.example.com

    steps:
      - uses: actions/checkout@v4

      - name: Configure AWS credentials
        uses: aws-actions/configure-aws-credentials@v4
        with:
          aws-access-key-id: ${{ secrets.AWS_ACCESS_KEY_ID }}
          aws-secret-access-key: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
          aws-region: us-east-1

      - name: Update kubeconfig
        run: |
          aws eks update-kubeconfig --name production-cluster --region us-east-1

      - name: Deploy to Kubernetes
        run: |
          kubectl set image deployment/myapp             myapp=${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:main             -n production
          kubectl rollout status deployment/myapp -n production

      - name: Verify deployment
        run: |
          kubectl get pods -n production
          kubectl get svc -n production

# Example: EKS cluster with Terraform
terraform {
  required_providers {
    aws = {
      source  = "hashicorp/aws"
      version = "~> 5.0"
    }
  }
}

provider "aws" {
  region = var.aws_region
}

module "vpc" {
  source = "terraform-aws-modules/vpc/aws"

  name = "eks-vpc"
  cidr = "10.0.0.0/16"

  azs             = ["us-east-1a", "us-east-1b", "us-east-1c"]
  private_subnets = ["10.0.1.0/24", "10.0.2.0/24", "10.0.3.0/24"]
  public_subnets  = ["10.0.101.0/24", "10.0.102.0/24", "10.0.103.0/24"]

  enable_nat_gateway = true
  enable_dns_hostnames = true

  tags = {
    Environment = var.environment
    Terraform   = "true"
  }
}

module "eks" {
  source = "terraform-aws-modules/eks/aws"

  cluster_name    = "production-eks"
  cluster_version = "1.30"

  vpc_id     = module.vpc.vpc_id
  subnet_ids = module.vpc.private_subnets

  eks_managed_node_groups = {
    general = {
      desired_size = 3
      min_size     = 2
      max_size     = 5

      instance_types = ["t3.medium"]
      capacity_type  = "ON_DEMAND"
    }

    spot = {
      desired_size = 2
      min_size     = 0
      max_size     = 10

      instance_types = ["t3.medium", "t3a.medium"]
      capacity_type  = "SPOT"
    }
  }

  tags = {
    Environment = var.environment
  }
}