Kubernetes – Hands-on

Pods, ReplicaSets, Deployments, Services, Ingress, ConfigMaps, and Secrets.

kubectl get pods -A
kubectl describe pod/my-pod
kubectl apply -f deployment.yaml
kubectl logs deploy/myapp -f
kubectl exec -it deploy/myapp -- sh

get lists resources; describe shows details and events; apply creates or updates from YAML; logs -f streams logs; exec runs a command inside a container.

# deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata: { name: nginx }
spec:
  replicas: 2
  selector: { matchLabels: { app: nginx } }
  template:
    metadata: { labels: { app: nginx } }
    spec:
      containers:
        - name: nginx
          image: nginx:alpine
---
# service.yaml
apiVersion: v1
kind: Service
metadata: { name: nginx }
spec:
  type: ClusterIP
  selector: { app: nginx }
  ports: [{ port: 80, targetPort: 80 }]

kubectl get ns
kubectl config get-contexts
kubectl config use-context my-cluster

helm repo add bitnami https://charts.bitnami.com/bitnami
helm install my-nginx oci://registry-1.docker.io/bitnamicharts/nginx

# configmap.yaml
apiVersion: v1
kind: ConfigMap
metadata: { name: nginx-html }
data:
  index.html: |
    <h1>Hello from ConfigMap</h1>
---
# deployment mounts the config
apiVersion: apps/v1
kind: Deployment
metadata: { name: nginx }
spec:
  replicas: 1
  selector: { matchLabels: { app: nginx } }
  template:
    metadata: { labels: { app: nginx } }
    spec:
      containers:
        - name: nginx
          image: nginx:alpine
          volumeMounts:
            - name: html
              mountPath: /usr/share/nginx/html
      volumes:
        - name: html
          configMap: { name: nginx-html }