k8s deployment of pgadmin with server setup from env variable

pgadmin.yaml

---
apiVersion: v1
kind: Service
metadata:
  labels:
    app: pgadmin
  name: pgadmin
spec:
  ports:
    - name: pgadmin
      port: 80
      targetPort: 80
  selector:
    app: pgadmin
  type: NodePort
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: pgadmin
spec:
  replicas: 1
  selector:
    matchLabels:
      app: pgadmin
  template:
    metadata:
      labels:
        app: pgadmin
    spec:
      initContainers:
        - name: server-setup
          image: busybox
          command: ["sh", "-c"]
          args:
            - |
              # pgpass file is relative to user storage
              echo '{"Servers":{"1":{"Name":"db",  "Group": "Servers","Host":"'"${POSTGRES_SERVER}"'","Port":5432,"MaintenanceDB":"postgres","Username":"postgres","PassFile":"../../../../../pgpass","SSLMode":"prefer"}}}' >/data/servers.json
              echo ${POSTGRES_SERVER}:5432:*:postgres:${POSTGRES_PASSWORD} > /data/pgpass
              chmod 0600 /data/pgpass
              chown 5050:5050 /data/pgpass
          volumeMounts:
            - name: config-volume
              mountPath: /data/
          env:
            - name: POSTGRES_SERVER
              valueFrom:
                secretKeyRef:
                  key: host
                  name: my-secret-rds
            - name: POSTGRES_PASSWORD
              valueFrom:
                secretKeyRef:
                  key: password
                  name: my-secret-rds
            - name: POSTGRES_DB
              value: postgres
      containers:
        - env:
            - name: PGADMIN_DEFAULT_EMAIL
              value: [email protected]
            - name: PGADMIN_DEFAULT_PASSWORD
              value: mypass
            - name: PGADMIN_PORT
              value: "80"
          image: dpage/pgadmin4:latest
          imagePullPolicy: IfNotPresent
          name: pgadmin
          ports:
            - containerPort: 80
          resources:
            limits:
              memory: 4096Mi
          volumeMounts:
            - mountPath: "/pgadmin4/servers.json"
              subPath: "servers.json"
              name: config-volume
              readOnly: true
            - mountPath: "/pgpass"
              subPath: "pgpass"
              name: config-volume
              readOnly: true
      volumes:
        - name: config-volume
          emptyDir: {}