How to mount PostgreSQL data directory in Kubernetes? - postgresql

Question

I'm using minikube to run kubernetes locally. My local k8s have two pods which one of them is PostgreSQL and another one is my own app. I've mounted a PersistentVolume and PersistentVolumeClaim in order to make a stateful pod for PostgreSQL:
kind: PersistentVolume
apiVersion: v1
metadata:
name: postgres-pv-volume
labels:
type: local
spec:
storageClassName: manual
capacity:
storage: 10Gi
accessModes:
- ReadWriteOnce
hostPath:
path: "/data/psql"
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: postgres-pv-claim
spec:
storageClassName: manual
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 10Gi
Here is PostgreSQL deployment yaml file:
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: postgres
spec:
replicas: 1
template:
metadata:
labels:
name: postgres
spec:
containers:
- name: postgres
imagePullPolicy: Never
image: postgres:9.6
ports:
- name: postgres
containerPort: 5432
volumeMounts:
- mountPath: /var/lib/postgresql
name: postgres-persistent-storage
volumes:
- name: postgres-persistent-storage
persistentVolumeClaim:
claimName: postgres-pv-claim
The problem is that PostgreSQL service doesn't start and this error occurs when I run its pod:
Error: /var/lib/postgresql/9.6/main is not accessible; please fix the directory permissions (/var/lib/postgresql/9.6/ should be world readable)
No PostgreSQL clusters exist; see "man pg_createcluster" ... (warning).
I've checked inside of PostgreSQL pod and I found that /var/lib/postgresql is empty, just like /data/psql In minikube host.
Can anyone help?

Answer 1

Change:
volumeMounts:
- mountPath: /var/lib/postgresql
to
volumeMounts:
- mountPath: /var/lib/postgresql/data
With the wrong mountPoint postgres executables were overridden.
I attach an image with the data I see from inside the pod (on the left) and from inside minikube space (on the right, the little shell from virtualbox).