apiVersion: apps/v1
kind: Deployment
metadata:
  name: postgres-deployment
spec:
  replicas: 1
  selector:
    matchLabels:
      component: postgres
  template:
    metadata:
      labels:
        component: postgres
    spec:
      volumes:
        - name: postgres-storage
          persistentVolumeClaim:
            claimName: database-persistent-volume-claim
      containers:
        - name: postgres
          image: postgres
          ports:
            - containerPort: 5432
          volumeMounts:
            - name: postgres-storage
              mountPath: /var/lib/postgresql/data
              subPath: postgres
          env:
            - name: PGPASSWORD
              valueFrom:
                secretKeyRef:
                  name: pgpassword # Kubernetes wird nach dem Objekt Secret "pgpassword" suchen "k create secret generic pgpassword --from-literal PGPASSWORD=password123"
                  key: PGPASSWORD # In unserem Fall das Objekt Secret mit dem Namen "pgpassword" beinhaltet den Schlüssel PGPASSWORD mit dem Wert password123