Postgres StatefulSet created succesfully - but not ready

Question

I have a yaml file that creates a namespace, a persistent volume, a persistent volume claim and a statefulset that uses the pvc. When I run this file with kubectl apply -f myfile.yaml, I don't get any errors.

apiVersion: v1
kind: Namespace
metadata:
  name: mynamespace

---

apiVersion: v1
kind: PersistentVolume
metadata:
  namespace: mynamespace
  name: postgres-pv
  labels:
    name: postgres-volume 
spec:
  storageClassName: manual # same storage class as pvc
  capacity:
    storage: 5Gi
  accessModes:
    - ReadWriteMany
  persistentVolumeReclaimPolicy: Retain
  nfs:
    server: 10.0.0.11 # ip addres of nfs server
    path: "/mnt/kubernetes-nfs-volume/customer1/postgres" # path to directory

---

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  namespace: mynamespace
  name: postgres-pvc
  labels:
    name: postgres-volume 
spec:
  storageClassName: manual
  accessModes:
    - ReadWriteMany #  must be the same as PersistentVolume
  resources:
    requests:
      storage: 5Gi

---

apiVersion: v1
kind: ConfigMap
metadata:
  name: postgres-configuration
  namespace: mynamespace
  labels:
    app: postgres
data:
  POSTGRES_DB: databasename
  POSTGRES_USER: mydatabaseuser
  POSTGRES_PASSWORD: mysupersecretpassword

---

apiVersion: apps/v1
kind: StatefulSet
metadata:
  namespace: mynamespace
  name: postgres-statefulset
  labels:
    app: postgres
spec:
  serviceName: "postgres"
  replicas: 1
  selector:
    matchLabels:
      app: postgres
  template:
    metadata:
      labels:
        app: postgres
    spec:
      containers:
      - name: postgres
        image: postgres:13
        envFrom:
        - configMapRef:
            name: postgres-configuration
        ports:
        - containerPort: 5432
          name: postgresdb
        volumeMounts:
        - name: pv-data
          mountPath: /var/lib/postgresql/data
      volumes:
      - name: pv-data
        persistentVolumeClaim:
          claimName: postgres-pvc

---

apiVersion: v1
kind: Service
metadata:
  namespace: mynamespace
  name: postgres
  labels:
    app: postgres
spec:
  type: NodePort
  ports:
   - port: 5432
  selector:
   app: postgres

Next, when I run kubectl describe -n mynamespace postgres-statefulset, I get the following output:

Looks good so far! However, running kubectl get statefulset -n mynamespace returns this:

What am I doing wrong? Also, the PV and PVC have been set up correctly, as I can use them with an nginx deployment for testing purposes succesfully. I have deleted everything in my cluster before running this script.

The output of kubectl get events -n mynamespace is as follows:

Answer 1

Found it out myself. On the fileserver with the NFS disk, I had to update /etc/exports to include no_root_squash on the folder that the postgres container uses as a mount. I figured this out by checking the logs of the pod, which had the error message chown: changing ownership of ‘/var/lib/postgresql/data’: Operation not permitted and googling that error.