Can't reach database server at postgres-srv:5432 Please make sure your database server is running at postgres-srv:5432.

depl.yaml

apiVersion: v1
kind: ConfigMap
metadata:
  name: postgres-config
  labels:
    app: postgres
data:
  POSTGRES_DB: postgresdb
  POSTGRES_USER: postgres
  POSTGRES_PASSWORD: root
---
kind: PersistentVolume
apiVersion: v1
metadata:
  name: postgres-pv-volume
  labels:
    app: postgres
    type: local
spec:
  storageClassName: manual
  capacity:
    storage: 5Gi
  accessModes:
    - ReadWriteMany
  hostPath:
    path: /var/lib/data
---
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: postgres-pv-claim
  labels:
    app: postgres
spec:
  storageClassName: manual
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 5Gi
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: postgres
spec:
  replicas: 1
  selector:
    matchLabels:
      app: postgres
  template:
    metadata:
      labels:
        app: postgres
    spec:
      containers:
        - name: postgres
          image: postgres:latest
          imagePullPolicy: "IfNotPresent"
          envFrom:
            - configMapRef:
                name: postgres-config
          volumeMounts:
            - mountPath: /var/lib/postgresql/data
              name: postgredb
      volumes:
        - name: postgredb
          persistentVolumeClaim:
            claimName: postgres-pv-claim

Service:

apiVersion: v1
kind: Service
metadata:
  name: postgres-srv
spec:
  selector:
    app: postgres
  ports:
    - name: db
      protocol: TCP
      port: 5432
      targetPort: 5432

postgres-srv      ClusterIP   10.108.208.56    <none>        5432/TCP            4m59s

Connection Url:

DATABASE_URL="postgresql://postgres:root@postgres-srv:5432/postgresdb?schema=public"