Kubernetes Day-to-Day Operational Tasks

1. Troubleshooting Pods

• Check Status: kubectl get pods. Look for status other than Running (e.g., CrashLoopBackOff, Pending, ImagePullBackOff).
• Describe: kubectl describe pod <pod_name>. Check the "Events" section at the bottom for errors like scheduling failures or probe failures.
• Logs: kubectl logs <pod_name>. Add -p to see logs from the previous instance if the pod crashed.

2. Cluster Maintenance

• Node Status: kubectl get nodes. Ensure all nodes are Ready.
• Top Nodes/Pods: kubectl top nodes and kubectl top pods to see resource consumption (requires Metrics Server).
• Cordon/Drain: Before maintenance on a node (e.g., OS upgrade):
  • kubectl cordon <node_name>: Mark node as unschedulable.
  • kubectl drain <node_name> --ignore-daemonsets: Evict all pods to other nodes.

3. Deployment Management

• Scale: Manually scale a deployment.
  • kubectl scale deployment my-app --replicas=5
• Rollout Restart: Restart all pods in a deployment (useful to pick up config changes).
  • kubectl rollout restart deployment my-app
• Rollback: Undo a failed deployment.
  • kubectl rollout undo deployment my-app

4. Context Switching

• Switch Context: kubectl config use-context <context_name> (or use tools like kubectx) to switch between dev, staging, and prod clusters.
• Switch Namespace: kubectl config set-context --current --namespace=<namespace> (or use kubens).