/blue-green-deployment

allowed-tools: Read, Write, Edit, Bash
argument-hint: [strategy] | setup | deploy | switch | rollback | status
description: Implement blue-green deployment strategy with zero-downtime switching, health validation, and automatic rollback

Blue-Green Deployment Strategy

Implement blue-green deployment: $ARGUMENTS

Current Infrastructure State

• Load balancer config: @nginx.conf or @haproxy.cfg or cloud LB configuration
• Current deployment: !`curl -s https://api.example.com/version 2>/dev/null || echo "Version endpoint needed"`
• Container orchestration: !`kubectl get deployments 2>/dev/null || docker service ls 2>/dev/null || echo "Container platform detection needed"`
• Health endpoints: !`curl -s https://api.example.com/health 2>/dev/null | jq -r '.status // "Unknown"' || echo "Health check setup needed"`
• DNS configuration: Check for DNS management capabilities

Task

Implement production-grade blue-green deployment with comprehensive validation and monitoring.

Blue-Green Architecture Components

1. **Infrastructure Setup**

Load Balancer Configuration (NGINX)

upstream blue {
    server blue-app-1:3000;
    server blue-app-2:3000;
    server blue-app-3:3000;
}

upstream green {
    server green-app-1:3000;
    server green-app-2:3000;
    server green-app-3:3000;
}

# Current active environment
upstream active {
    server blue-app-1:3000;
    server blue-app-2:3000;
    server blue-app-3:3000;
}

server {
    listen 80;
    server_name example.com;

    location / {
        proxy_pass http://active;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Environment $environment;
        
        # Health check configuration
        proxy_connect_timeout 5s;
        proxy_send_timeout 5s;
        proxy_read_timeout 5s;
        
        # Retry configuration
        proxy_next_upstream error timeout invalid_header http_500 http_502 http_503;
        proxy_next_upstream_tries 2;
    }

    # Health check endpoint
    location /health {
        access_log off;
        proxy_pass http://active/health;
        proxy_connect_timeout 1s;
        proxy_send_timeout 1s;
        proxy_read_timeout 1s;
    }

    # Environment indicator
    location /environment {
        access_log off;
        return 200 $environment;
        add_header Content-Type text/plain;
    }
}

HAProxy Configuration

global
    daemon
    log 127.0.0.1:514 local0
    stats socket /var/run/haproxy.sock mode 600 level admin

defaults
    mode http
    timeout connect 5000ms
    timeout client 50000ms
    timeout server 50000ms
    option httplog
    option dontlognull

# Blue environment
backend blue_backend
    balance roundrobin
    option httpchk GET /health
    http-check expect status 200
    server blue1 blue-app-1:3000 check
    server blue2 blue-app-2:3000 check
    server blue3 blue-app-3:3000 check

# Green environment
backend green_backend
    balance roundrobin
    option httpchk GET /health
    http-check expect status 200
    server green1 green-app-1:3000 check
    server green2 green-app-2:3000 check
    server green3 green-app-3:3000 check

# Frontend with switching logic
frontend main_frontend
    bind *:80
    # Environment switching via ACL
    use_backend blue_backend if { var(txn.environment) -m str blue }
    use_backend green_backend if { var(txn.environment) -m str green }
    default_backend blue_backend  # Default to blue

# Stats interface
frontend stats
    bind *:8404
    stats enable
    stats uri /stats
    stats refresh 5s

2. **Kubernetes Blue-Green Implementation**

Blue-Green Service Management

# blue-service.yaml
apiVersion: v1
kind: Service
metadata:
  name: app-service-blue
  labels:
    app: myapp
    environment: blue
spec:
  selector:
    app: myapp
    environment: blue
  ports:
    - port: 80
      targetPort: 3000
  type: ClusterIP

---
# green-service.yaml
apiVersion: v1
kind: Service
metadata:
  name: app-service-green
  labels:
    app: myapp
    environment: green
spec:
  selector:
    app: myapp
    environment: green
  ports:
    - port: 80
      targetPort: 3000
  type: ClusterIP

---
# active-service.yaml (points to current active environment)
apiVersion: v1
kind: Service
metadata:
  name: app-service-active
  labels:
    app: myapp
    environment: active
spec:
  selector:
    app: myapp
    environment: blue  # Switch this to 'green' during deployment
  ports:
    - port: 80
      targetPort: 3000
  type: LoadBalancer

Blue-Green Deployments

# blue-deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: app-blue
  labels:
    app: myapp
    environment: blue
spec:
  replicas: 3
  selector:
    matchLabels:
      app: myapp
      environment: blue
  template:
    metadata:
      labels:
        app: myapp
        environment: blue
    spec:
      containers:
      - name: app
        image: myapp:v1.0.0
        ports:
        - containerPort: 3000
        env:
        - name: ENVIRONMENT
          value: "blue"
        - name: VERSION
          value: "v1.0.0"
        livenessProbe:
          httpGet:
            path: /health
            port: 3000
          initialDelaySeconds: 30
          periodSeconds: 10
        readinessProbe:
          httpGet:
            path: /ready
            port: 3000
          initialDelaySeconds: 5
          periodSeconds: 5
        resources:
          requests:
            memory: "128Mi"
            cpu: "100m"
          limits:
            memory: "512Mi"
            cpu: "500m"

---
# green-deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: app-green
  labels:
    app: myapp
    environment: green
spec:
  replicas: 3
  selector:
    matchLabels:
      app: myapp
      environment: green
  template:
    metadata:
      labels:
        app: myapp
        environment: green