kubernetes-operations

# Kubernetes Operations

Expert knowledge for Kubernetes cluster management, deployment, and troubleshooting with mastery of kubectl and cloud-native patterns.

## Core Expertise

**Kubernetes Operations**
- **Workload Management**: Deployments, StatefulSets, DaemonSets, Jobs, and CronJobs
- **Networking**: Services, Ingress, NetworkPolicies, and DNS configuration
- **Configuration & Storage**: ConfigMaps, Secrets, PersistentVolumes, and PersistentVolumeClaims
- **Troubleshooting**: Debugging pods, analyzing logs, and inspecting cluster events

## Cluster Operations Process

1. **Manifest First**: Always prefer declarative YAML manifests for resource management
2. **Validate & Dry-Run**: Use `kubectl apply --dry-run=client` to validate changes
3. **Inspect & Verify**: After applying changes, verify with `kubectl get`, `kubectl describe`, `kubectl logs`
4. **Monitor Health**: Continuously check status of nodes, pods, and services
5. **Clean Up**: Ensure old or unused resources are properly garbage collected

## Essential Commands

```bash
# Resource management
kubectl apply -f manifest.yaml
kubectl get pods -A
kubectl describe pod <pod-name>
kubectl logs -f <pod-name>
kubectl exec -it <pod-name> -- /bin/bash

# Debugging
kubectl get events --sort-by='.lastTimestamp'
kubectl top nodes
kubectl top pods --containers
kubectl port-forward <pod-name> 8080:80

# Deployment management
kubectl rollout status deployment/<name>
kubectl rollout history deployment/<name>
kubectl rollout undo deployment/<name>

# Cluster inspection
kubectl cluster-info
kubectl get nodes -o wide
kubectl api-resources
```

## Key Debugging Patterns

**Pod Debugging**
```bash
# Pod inspection
kubectl describe pod <pod-name>
kubectl get pod <pod-name> -o yaml
kubectl logs <pod-name> --previous

# Interactive debugging
kubectl exec -it <pod-name> -- /bin/bash
kubectl debug <pod-name> -it --image=busybox
kubectl port-forward <pod-name> 8080:80
```

**Networking Troubleshooting**
```bash
# Service debugg