Postgres on Azure kubernetes volume permission error

Question

I'm trying to deploy Postgresql on Azure Kubernetes with data persistency. So I'm using PVC. I searched lots of posts on here, most of them offered yaml files like below, but it's giving the error below;

chmod: changing permissions of '/var/lib/postgresql/data/pgdata': Operation not permitted
The files belonging to this database system will be owned by user "postgres".
This user must also own the server process.

The database cluster will be initialized with locale "en_US.utf8".
The default database encoding has accordingly been set to "UTF8".
The default text search configuration will be set to "english".

Data page checksums are disabled.

initdb: error: could not change permissions of directory "/var/lib/postgresql/data/pgdata": Operation not permitted
fixing permissions on existing directory /var/lib/postgresql/data/pgdata ...

deployment yaml file is below;

apiVersion: apps/v1
kind: Deployment
metadata:
  name: postgresql
spec:
  replicas: 1
  selector:
    matchLabels:
      app: postgresql
  template:
    metadata:
      labels:
        app: postgresql
    spec:
      containers:
        - name: postgresql
          image: postgres:13.2
          securityContext:
            runAsUser: 999
          imagePullPolicy: "IfNotPresent"
          ports:
            - containerPort: 5432
          envFrom:
            - secretRef:
                name: postgresql-secret
          volumeMounts:
            - mountPath: /var/lib/postgresql/data
              name: postgredb-kap
      volumes:
        - name: postgredb-kap
          persistentVolumeClaim:
            claimName: postgresql-pvc

Secret yaml is below;

apiVersion: v1
kind: Secret
metadata:
  name: postgresql-secret
type: Opaque
data:
  POSTGRES_DB: a2V5sd4=
  POSTGRES_USER: cG9zdGdyZXNhZG1pbg==
  POSTGRES_PASSWORD: c234Rw==
  PGDATA: L3Za234dGF0YQ==

pvc and sc yaml files are below:

kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: postgresql-pvc
  labels:
    app: postgresql
spec:
  storageClassName: postgresql-sc
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 5Gi
---
allowVolumeExpansion: true
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: postgresql-sc
mountOptions:
- dir_mode=0777
- file_mode=0777
- uid=1000
- gid=1000
parameters:
  skuName: Standard_LRS
provisioner: kubernetes.io/azure-file
reclaimPolicy: Retain

So when I use the mountpath like "- mountPath: /var/lib/postgresql/", it's working. I can reach the DB and it's good. But when I delete the pod and recreating, there is no DB! So no data persistency.

Can you please help, what am I missing here?

Thanks!

Answer 1

Based on the helpful answer from Matt. For bitnami postgresql the initContainer also works but with a slightly different configuration:

      initContainers:
        - name: init
          image: alpine
          command: ["sh", "-c", "chown 1001:1001 /bitnami/postgresql"]
          volumeMounts:
            - mountPath: /bitnami/postgresql
              name: postgres-volume