Examples.md

Kubernetes YAML Configuration Examples

1. Pod Configuration

apiVersion: v1
kind: Pod
metadata:
  name: nginx-pod
  labels:
    app: nginx
spec:
  containers:
  - name: nginx
    image: nginx:latest
    ports:
    - containerPort: 80
    resources:
      requests:
        cpu: 100m
        memory: 128Mi
      limits:
        cpu: 250m
        memory: 256Mi

2. Deployment Configuration

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:latest
        ports:
        - containerPort: 80
        readinessProbe:
          httpGet:
            path: /
            port: 80
          initialDelaySeconds: 5
          periodSeconds: 10
        livenessProbe:
          httpGet:
            path: /
            port: 80
          initialDelaySeconds: 15
          periodSeconds: 20

3. Service Configuration

apiVersion: v1
kind: Service
metadata:
  name: nginx-service
spec:
  selector:
    app: nginx
  type: LoadBalancer
  ports:
  - protocol: TCP
    port: 80
    targetPort: 80

4. ConfigMap

apiVersion: v1
kind: ConfigMap
metadata:
  name: app-config
data:
  DATABASE_HOST: postgres-service
  DATABASE_PORT: "5432"
  LOG_LEVEL: info

5. Secret

apiVersion: v1
kind: Secret
metadata:
  name: app-secrets
type: Opaque
stringData:
  DB_PASSWORD: your-secure-password
  API_KEY: your-api-key

6. Persistent Volume Claim

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: database-storage
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 5Gi

7. StatefulSet

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: postgres-statefulset
spec:
  serviceName: "postgres"
  replicas: 3
  selector:
    matchLabels:
      app: postgres
  template:
    metadata:
      labels:
        app: postgres
    spec:
      containers:
      - name: postgres
        image: postgres:13
        ports:
        - containerPort: 5432
        volumeMounts:
        - name: postgres-storage
          mountPath: /var/lib/postgresql/data
  volumeClaimTemplates:
  - metadata:
      name: postgres-storage
    spec:
      accessModes: [ "ReadWriteOnce" ]
      resources:
        requests:
          storage: 5Gi

8. Horizontal Pod Autoscaler

apiVersion: autoscaling/v2beta1
kind: HorizontalPodAutoscaler
metadata:
  name: nginx-autoscaler
spec:
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: nginx-deployment
  minReplicas: 1
  maxReplicas: 10
  metrics:
  - type: Resource
    resource:
      name: cpu
      targetAverageUtilization: 70

9. Network Policy

apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: allow-nginx
spec:
  podSelector:
    matchLabels:
      app: nginx
  ingress:
  - from:
    - podSelector:
        matchLabels:
          allow-nginx-access: "true"
    ports:
    - protocol: TCP
      port: 80

10. Role and RoleBinding

# Role
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  namespace: default
  name: pod-reader
rules:
- apiGroups: [""]
  resources: ["pods"]
  verbs: ["get", "watch", "list"]

# RoleBinding
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: read-pods
  namespace: default
subjects:
- kind: User
  name: jane
  apiGroup: rbac.authorization.k8s.io
roleRef:
  kind: Role
  name: pod-reader
  apiGroup: rbac.authorization.k8s.io

11. Ingress

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: minimal-ingress
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /
spec:
  rules:
  - http:
      paths:
      - path: /service1
        pathType: Prefix
        backend:
          service:
            name: service1
            port:
              number: 80

Important Notes

• Always validate YAML files using kubectl apply --dry-run=client -f your-file.yaml
• Use proper indentation (2 or 4 spaces)
• Match API versions with your Kubernetes cluster
• Keep sensitive information in Secrets
• Use labels and selectors effectively
• Follow least privilege principle in RBAC