operating-k8s-local

# Operating K8s Local

## Quick Start

```bash
# Start cluster with resources
minikube start --memory=8192 --cpus=4

# Enable essential addons
minikube addons enable ingress
minikube addons enable metrics-server

# Point Docker to Minikube
eval $(minikube docker-env)

# Build and deploy
docker build -t myapp:local .
kubectl apply -f k8s/
```

## Minikube Essentials

### Cluster Management

```bash
minikube start                          # Start with defaults
minikube start --memory=8192 --cpus=4   # With resources
minikube start --driver=docker          # Specific driver
minikube status                         # Check status
minikube stop                           # Stop (preserves state)
minikube delete                         # Delete completely
```

### Multiple Clusters

```bash
minikube start -p my-cluster    # Named cluster
minikube profile my-cluster     # Switch clusters
minikube profile list           # List all
```

### Addons

```bash
minikube addons list                    # List available
minikube addons enable ingress          # REQUIRED for external access
minikube addons enable metrics-server   # For kubectl top
minikube addons enable dashboard        # Web UI
minikube addons enable storage-provisioner  # For PVCs
```

### Accessing Services

```bash
# Method 1: NodePort
minikube service my-service --url

# Method 2: LoadBalancer (requires tunnel)
minikube tunnel  # Run in separate terminal

# Method 3: Port forward
kubectl port-forward svc/my-service 8080:80
```

### Using Local Docker Images

```bash
# Point to Minikube's Docker
eval $(minikube docker-env)

# Build directly into Minikube
docker build -t my-app:local .

# Use imagePullPolicy: Never in manifests
# Reset to local Docker
eval $(minikube docker-env -u)
```

## kubectl Essentials

### Context Management

```bash
kubectl config current-context              # Current context
kubectl config get-contexts                 # List all
kubectl config use-context minikube         # Switch
kubectl config set-context --current --namespace=my-ns  # Set default ns
```

### Getting Information

```bash
kubectl get pods                    # Current namespace
kubectl get pods -A                 # All namespaces
kubectl get pods -o wide            # With node/IP
kubectl get all                     # All resources
kubectl describe pod my-pod         # Detailed info
kubectl get events --sort-by='.lastTimestamp'  # Recent events
```

### Logs

```bash
kubectl logs my-pod                 # Current logs
kubectl logs my-pod -f              # Follow
kubectl logs my-pod -c container    # Specific container
kubectl logs my-pod --previous      # After crash
kubectl logs my-pod --tail=50       # Last 50 lines
```

### Creating Resources

```bash
kubectl apply -f manifest.yaml
kubectl create deployment nginx --image=nginx
kubectl create configmap my-config --from-literal=key=value
kubectl create secret generic my-secret --from-literal=password=secret

# Generate YAML
kubectl create deployment nginx --image=nginx --dry-run=client -o yaml
```

### Modifying Resources

```bash
kubectl edit deployment my-deploy
kubectl scale deployment my-deploy --replicas=3
kubectl set image deployment/my-deploy container=image:v2
kubectl rollout restart deployment/my-deploy
```

### Debugging

```bash
kubectl exec -it my-pod -- /bin/sh          # Shell into pod
kubectl exec my-pod -- env                   # Run command
kubectl port-forward pod/my-pod 8080:80     # Forward port
kubectl top pods                             # Resource usage
kubectl top nodes
```

## Resource Manifests

### Deployment

```yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-deploy
spec:
  replicas: 3
  selector:
    matchLabels:
      app: my-app
  template:
    metadata:
      labels:
        app: my-app
    spec:
      containers:
        - name: main
          image: my-app:local
          imagePullPolicy: Never  # For local images
          ports:
            - containerPort: 8000
          livenessProbe:
            httpGet:
              path: /health
              port: 8000
            initialDelaySeconds: 30
          readinessProbe:
            httpGet:
              path: /health
              port: 8000
            initialDelaySeconds: 5
```

### Service

```yaml
apiVersion: v1
kind: Service
metadata:
  name: my-service
spec:
  type: ClusterIP  # or NodePort, LoadBalancer
  selector:
    app: my-app
  ports:
    - port: 80
      targetPort: 8000
```

### ConfigMap & Secret

```yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: my-config
data:
  DATABASE_HOST: postgres
  DATABASE_PORT: "5432"
---
apiVersion: v1
kind: Secret
metadata:
  name: my-secret
type: Opaque
stringData:
  password: mysecretpassword
```

### Ingress

```yaml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: my-ingress
spec:
  ingressClassName: nginx
  rules:
    - host: myapp.local
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: my-service
                port:
                  number: 80
```

## Local Development Workflow

```bash
# 1. Start Minikube
minikube start --memory=8192 --cpus=4

# 2. Enable addons
minikube addons enable ingress
minikube addons enable metrics-server

# 3. Point to Minikube Docker
eval $(minikube docker-env)

# 4. Build images
docker build -t myapp/api:local ./api
docker build -t myapp/web:local ./web

# 5. Deploy
kubectl apply -f k8s/

# 6. Access
minikube service myapp-web --url
# Or with ingress:
echo "$(minikube ip) myapp.local" | sudo tee -a /etc/hosts
```

## Debugging Quick Reference

```bash
# Pod not starting?
kubectl describe pod my-pod      # Check Events section

# Container crashing?
kubectl logs my-pod --previous   # Logs from crashed container

# Network issues?
kubectl exec -it my-pod -- nslookup my-service
kubectl exec -it my-pod -- wget -qO- http://my-service:80

# Resource issues?
kubectl top pods
kubectl top nodes
```

## Verification

Run: `python scripts/verify.py`

## Related Skills

- `containerizing-applications` - Docker and Helm charts
- `deploying-cloud-k8s` - Cloud Kubernetes deployment