kubernetes

## What I do - Create and manage Kubernetes manifests - Deploy applications using kubectl and Helm - Configure services, ingress, and networking - Set up persistent storage - Implement config maps and secrets - Manage deployments with rolling updates - Configure resource limits and auto-scaling ## When to use me When deploying containerized applications to Kubernetes clusters. ## Pod ```yaml apiVersion: v1 kind: Pod metadata: name: my-app labels: app: my-app spec: containers: - name: app image: my-app:latest ports: - containerPort: 8080 resources: requests: memory: "64Mi" cpu: "250m" limits: memory: "128Mi" cpu: "500m" ``` ## Deployment ```yaml apiVersion: apps/v1 kind: Deployment metadata: name: my-app spec: replicas: 3 selector: matchLabels: app: my-app template: metadata: labels: app: my-app spec: containers: - name: app image: my-app:v1 ports: - containerPort: 8080 env: - name: DATABASE_URL valueFrom: secretKeyRef: name: db-credentials key: url ``` ## Service ```yaml apiVersion: v1 kind: Service metadata: name: my-app spec: selector: app: my-app ports: - port: 80 targetPort: 8080 type: ClusterIP # or NodePort, LoadBalancer ``` ## Ingress ```yaml apiVersion: networking.k8s.io/v1 kind: Ingress metadata: name: my-app annotations: nginx.ingress.kubernetes.io/rewrite-target: / spec: rules: - host: myapp.example.com http: paths: - path: / pathType: Prefix backend: service: name: my-app port: number: 80 ``` ## ConfigMap & Secrets ```yaml apiVersion: v1 kind: ConfigMap metadata: name: app-config data: database.json: | {"host": "localhost", "port": 5432} --- apiVersion: v1 kind: Secret metadata: name: app-secret type: Opaque stringData: api-key: your-api-key-here ``` ## StatefulSet ```yaml apiVersion: apps/v1 kind: StatefulSet metadata: name: mysql spec: serviceName: mysql replicas: 3 selector: matchLabels: app: mysql template: spec: containers: - name: mysql image: mysql:8 volumeMounts: - name: data mountPath: /var/lib/mysql volumeClaimTemplates: - metadata: name: data spec: accessModes: ["ReadWriteOnce"] resources: requests: storage: 10Gi ``` ## Helm Chart ```bash # Install helm install my-release my-chart/ # Upgrade helm upgrade my-release my-chart/ --set image.tag=v2 # Values helm install my-release my-chart/ -f values.yaml ``` ```yaml # values.yaml replicaCount: 3 image: repository: my-app tag: latest pullPolicy: IfNotPresent service: type: ClusterIP port: 80 resources: limits: cpu: 500m memory: 256Mi ```