Kubernetes Deployment Strategies for Production

Kubernetes has revolutionized how we deploy and manage applications at scale. In this comprehensive guide, I'll walk you through proven deployment strategies that ensure zero-downtime deployments and robust monitoring.

Understanding Deployment Strategies

Rolling Updates

The default strategy in Kubernetes, rolling updates gradually replace old pods with new ones:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-app
spec:
  replicas: 3
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxUnavailable: 1
      maxSurge: 1

Blue-Green Deployments

Blue-green deployments maintain two identical production environments:

1. Blue: Current production environment
2. Green: New version environment

Switch traffic from blue to green once testing is complete.

Canary Deployments

Gradually roll out changes to a subset of users:

apiVersion: argoproj.io/v1alpha1
kind: Rollout
metadata:
  name: canary-demo
spec:
  replicas: 5
  strategy:
    canary:
      steps:
        - setWeight: 20
        - pause: { duration: 10m }
        - setWeight: 40
        - pause: { duration: 10m }
        - setWeight: 60
        - pause: { duration: 10m }
        - setWeight: 80
        - pause: { duration: 10m }

Monitoring and Observability

Health Checks

Implement proper health checks:

livenessProbe:
  httpGet:
    path: /health
    port: 8080
  initialDelaySeconds: 30
  periodSeconds: 10

readinessProbe:
  httpGet:
    path: /ready
    port: 8080
  initialDelaySeconds: 5
  periodSeconds: 5

Metrics and Logging

• Prometheus: Metrics collection
• Grafana: Visualization
• ELK Stack: Centralized logging
• Jaeger: Distributed tracing

Best Practices

1. Resource Limits: Always set CPU and memory limits
2. Security: Use RBAC and network policies
3. Backup: Regular etcd backups
4. Updates: Keep cluster components updated
5. Documentation: Maintain deployment runbooks

Conclusion

Successful Kubernetes deployments require careful planning, proper monitoring, and adherence to best practices. Start with rolling updates and gradually implement more sophisticated strategies as your needs grow.