mongodb microservice k8 persistent volume claim not persisting data - mongodb

Question

I have several microservices, each one with its own mongodb deployment. I would like to start with getting my auth service working with a persistent volume. I have watched courses where postgresql is used and read a lot in the kubernetes docs but am having trouble getting this to work for mongodb.
When I run skaffold dev the PVC is created with no errors. kubectl shows the PVC is in Bound status, and running describe on the PVC shows my mongo deployment as the user.
However, when I visit my client service in the browser, I signup, logout, signin again with no problem and then if I restart skaffold so it deletes and recreates the containers my data is gone and I have to signup again.
Here are my files
auth-mongo-depl.yaml
# auth-mongo service base deployment configuration
apiVersion: apps/v1
kind: Deployment
metadata:
name: auth-mongo-depl
spec:
replicas: 1
selector:
matchLabels:
app: auth-mongo
template:
metadata:
labels:
app: auth-mongo
spec:
volumes:
- name: auth-mongo-data
persistentVolumeClaim:
claimName: auth-mongo-pvc
containers:
- name: auth-mongo
image: mongo
ports:
- containerPort: 27017
name: 'auth-mongo-port'
volumeMounts:
- name: auth-mongo-data
mountPath: '/data/db'
---
# ClusterIp Service
apiVersion: v1
kind: Service
metadata:
name: auth-mongo-ip-srv
spec:
selector:
app: auth-mongo
type: ClusterIP
ports:
- name: auth-mongo-db
protocol: TCP
port: 27017
targetPort: 27017
---
# Persistent Volume Claim
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: auth-mongo-pvc
spec:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 500Mi
auth-depl.yaml
# auth service base deployment configuration
apiVersion: apps/v1
kind: Deployment
metadata:
name: auth-depl
spec:
replicas: 1
selector:
matchLabels:
app: auth
template:
metadata:
labels:
app: auth
spec:
containers:
- name: auth
image: isimmons33/ticketing-auth
env:
- name: MONGO_URI
value: 'mongodb://auth-mongo-ip-srv:27017/auth'
- name: JWT_KEY
valueFrom:
secretKeyRef:
name: jwt-secret
key: JWT_KEY
---
# ClusterIp Service
apiVersion: v1
kind: Service
metadata:
name: auth-ip-srv
spec:
selector:
app: auth
type: ClusterIP
ports:
- name: auth
protocol: TCP
port: 3000
targetPort: 3000
api/users portion of my ingress-srv.yaml
- path: /api/users/?(.*)
pathType: Prefix
backend:
service:
name: auth-ip-srv
port:
number: 3000
My client fires off a post request to /api/users/auth with which I can successfully signup or signin as long as I don't restart skaffold.
I even used kubectl to get a shell into my mongo deployment and queried to see the new user account there as it should be. But of course it is gone after restarting skaffold.
I am on Windows 10 but am running everything through WSL2 (Ubuntu)
Thanks for any help

Answer 1

It is highly recommended to use StatefulSets for running databases in Kubernetes. In Deployment if your pod crashes for some reason and creates new one, it's not guaranteed the pod will get patched to the same PV, hence the you loose the data.
Have a look on this https://kubernetes.io/blog/2017/01/running-mongodb-on-kubernetes-with-statefulsets

Answer 2

The solution as pointed out by raghu_manne was to use StatefulSets. But because the link posted is extremely old, here is the full solution that worked for me.
Also here is a youtube video I just found that explains StatefulSet and volumeClaimTemplates quite well.
How to run MongoDB with StatefulSets in Kubernetes
auth-mongo-depl.yaml
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: auth-mongo-depl
spec:
replicas: 1
serviceName: auth-mongo
selector:
matchLabels:
app: auth-mongo
template:
metadata:
labels:
app: auth-mongo
spec:
containers:
- name: auth-mongo
image: mongo
ports:
- containerPort: 27017
volumeMounts:
- name: auth-mongo-data
mountPath: /data/db
volumeClaimTemplates:
- metadata:
name: auth-mongo-data
spec:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 500Mi
---
# ClusterIp Service
apiVersion: v1
kind: Service
metadata:
name: auth-mongo-ip-srv
spec:
selector:
app: auth-mongo
type: ClusterIP
ports:
- name: auth-mongo-db
protocol: TCP
port: 27017
targetPort: 27017