Kubernetes deployment con ConfigMap, Secrets, PV + PVC

El Namespace organiza los recursos.
ConfigMap y Secret pasan variables de configuración y credenciales.
PV + PVC gestionan almacenamiento persistente.
Deployment + Service crean y exponen la app internamente.
Ingress + Nginx Controller permiten acceder desde fuera, usando el hostname myapp.local o la IP del LoadBalancer del controlador.

# 1. Namespace
00-namespace.yaml
apiVersion: v1
kind: Namespace
metadata:
  name: myapp-namespace

# 2. ConfigMap
01-configmap.yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: myapp-config
  namespace: myapp-namespace
data:
  APP_ENV: "production"
  APP_MESSAGE: "Hola desde ConfigMap!"

# 3. Secret
02-secret.yaml
apiVersion: v1
kind: Secret
metadata:
  name: myapp-secret
  namespace: myapp-namespace
type: Opaque
data:
  DB_PASSWORD: c3VwZXJwYXNzd29yZA==   # "superpassword" en base64
  API_KEY: YXBpa2V5MTIzNDU=           # "apikey12345" en base64

# 4. PersistentVolume
03-pv.yaml
apiVersion: v1
kind: PersistentVolume
metadata:
  name: app-pv
spec:
  capacity:
    storage: 1Gi
  accessModes:
    - ReadWriteOnce
  hostPath:
    path: /data/app

# 5. PersistentVolumeClaim
04-pvc.yaml
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: app-pvc
  namespace: myapp-namespace
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 1Gi

# 6. Deployment
05-deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: myapp-deployment
  namespace: myapp-namespace
spec:
  replicas: 2
  selector:
    matchLabels:
      app: myapp
  template:
    metadata:
      labels:
        app: myapp
    spec:
      containers:
      - name: myapp
        image: nginx:latest
        ports:
        - containerPort: 80
        env:
        - name: APP_ENV
          valueFrom:
            configMapKeyRef:
              name: myapp-config
              key: APP_ENV
        - name: APP_MESSAGE
          valueFrom:
            configMapKeyRef:
              name: myapp-config
              key: APP_MESSAGE
        - name: DB_PASSWORD
          valueFrom:
            secretKeyRef:
              name: myapp-secret
              key: DB_PASSWORD
        - name: API_KEY
          valueFrom:
            secretKeyRef:
              name: myapp-secret
              key: API_KEY
        volumeMounts:
        - name: app-storage
          mountPath: /usr/share/nginx/html/data
      volumes:
      - name: app-storage
        persistentVolumeClaim:
          claimName: app-pvc

# 7. Service
06-service.yaml
apiVersion: v1
kind: Service
metadata:
  name: myapp-service
  namespace: myapp-namespace
spec:
  selector:
    app: myapp
  ports:
    - port: 80
      targetPort: 80
  type: ClusterIP

# 8. Ingress
07-ingress.yaml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: myapp-ingress
  namespace: myapp-namespace
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /
spec:
  ingressClassName: nginx
  rules:
  - host: myapp.local
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: myapp-service
            port:
              number: 80

# 9. Ingress Nginx Controller (externo)
08-ingress-controller.yaml
apiVersion: v1
kind: Namespace
metadata:
  name: ingress-nginx
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: ingress-nginx-controller
  namespace: ingress-nginx
spec:
  replicas: 1
  selector:
    matchLabels:
      app: ingress-nginx-controller
  template:
    metadata:
      labels:
        app: ingress-nginx-controller
    spec:
      containers:
      - name: controller
        image: registry.k8s.io/ingress-nginx/controller:v1.11.0
        args:
        - "/nginx-ingress-controller"
        - "--ingress-class=nginx"
        ports:
        - containerPort: 80
        - containerPort: 443
---
apiVersion: v1
kind: Service
metadata:
  name: ingress-nginx-controller
  namespace: ingress-nginx
spec:
  type: LoadBalancer
  selector:
    app: ingress-nginx-controller
  ports:
  - name: http
    port: 80
    targetPort: 80
  - name: https
    port: 443
    targetPort: 443

# Aplicar todo
kubectl apply -f .