Kubernetes Resources

apiVersion: apps/v1
kind: Deployment
metadata:
  name: web-application
  namespace: production
  labels:
    app: web-application
spec:
  replicas: 3
  selector:
    matchLabels:
      app: web-application
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxSurge: 1
      maxUnavailable: 0
  template:
    metadata:
      labels:
        app: web-application
    spec:
      containers:
      - name: web-application
        image: nginx:1.25-alpine
        ports:
        - containerPort: 80
          name: http
        resources:
          limits:
            cpu: "500m"
            memory: "512Mi"
          requests:
            cpu: "100m"
            memory: "128Mi"
        livenessProbe:
          httpGet:
            path: /health
            port: http
          initialDelaySeconds: 30
          periodSeconds: 10
        readinessProbe:
          httpGet:
            path: /ready
            port: http
          initialDelaySeconds: 5
          periodSeconds: 5

apiVersion: v1
kind: Service
metadata:
  name: web-application
  namespace: production
  labels:
    app: web-application
spec:
  type: ClusterIP
  selector:
    app: web-application
  ports:
  - name: http
    port: 80
    targetPort: 80
    protocol: TCP
  - name: https
    port: 443
    targetPort: 443
    protocol: TCP

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: web-application
  namespace: production
  annotations:
    traefik.ingress.kubernetes.io/router.entrypoints: websecure
    traefik.ingress.kubernetes.io/router.tls: "true"
    traefik.ingress.kubernetes.io/router.middlewares: production-redirect@kubernetescrd
spec:
  ingressClassName: traefik
  tls:
  - hosts:
    - app.example.com
    secretName: app-tls-secret
  rules:
  - host: app.example.com
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: web-application
            port:
              number: 80

apiVersion: v1
kind: ConfigMap
metadata:
  name: app-config
  namespace: production
data:
  # Simple key-value pairs
  DATABASE_HOST: "postgres.database.svc.cluster.local"
  DATABASE_PORT: "5432"
  LOG_LEVEL: "info"

  # File-based configuration
  nginx.conf: |
    server {
        listen 80;
        server_name _;

        location / {
            root /usr/share/nginx/html;
            index index.html;
            try_files $uri $uri/ /index.html;
        }

        location /api {
            proxy_pass http://backend:8080;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
        }
    }

apiVersion: v1
kind: Secret
metadata:
  name: app-secrets
  namespace: production
type: Opaque
stringData:
  # Use stringData for plain text (auto-encoded to base64)
  DATABASE_USER: "app_user"
  DATABASE_PASSWORD: "secure-password-here"
  API_KEY: "your-api-key"

---
# For TLS certificates
apiVersion: v1
kind: Secret
metadata:
  name: app-tls-secret
  namespace: production
type: kubernetes.io/tls
data:
  # Base64-encoded certificate and key
  tls.crt: LS0tLS1CRUdJTi...
  tls.key: LS0tLS1CRUdJTi...

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: app-data
  namespace: production
spec:
  accessModes:
    - ReadWriteOnce
  storageClassName: longhorn
  resources:
    requests:
      storage: 10Gi

---
# For shared storage (ReadWriteMany)
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: shared-data
  namespace: production
spec:
  accessModes:
    - ReadWriteMany
  storageClassName: longhorn-nfs
  resources:
    requests:
      storage: 50Gi

apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: app-network-policy
  namespace: production
spec:
  podSelector:
    matchLabels:
      app: web-application
  policyTypes:
  - Ingress
  - Egress
  ingress:
  # Allow traffic from ingress controller
  - from:
    - namespaceSelector:
        matchLabels:
          name: traefik
    ports:
    - protocol: TCP
      port: 80
  # Allow traffic from same namespace
  - from:
    - podSelector: {}
  egress:
  # Allow DNS resolution
  - to:
    - namespaceSelector: {}
    ports:
    - protocol: UDP
      port: 53
  # Allow database access
  - to:
    - namespaceSelector:
        matchLabels:
          name: database
    ports:
    - protocol: TCP
      port: 5432

apiVersion: autoscaling/v2
kind: HorizontalPodAutoscaler
metadata:
  name: web-application-hpa
  namespace: production
spec:
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: web-application
  minReplicas: 2
  maxReplicas: 10
  metrics:
  - type: Resource
    resource:
      name: cpu
      target:
        type: Utilization
        averageUtilization: 70
  - type: Resource
    resource:
      name: memory
      target:
        type: Utilization
        averageUtilization: 80
  behavior:
    scaleDown:
      stabilizationWindowSeconds: 300
      policies:
      - type: Percent
        value: 10
        periodSeconds: 60
    scaleUp:
      stabilizationWindowSeconds: 0
      policies:
      - type: Percent
        value: 100
        periodSeconds: 15