How to mounts a directory from container into the host - kubernetes

Question

I create a deployment yaml for a microservice.
I am using hostpath volume type for persistentVolume and I have to copy data to a path in host. But I want to mount a directory from container into the host because data is in the container and I need this data in host.
My deployment yaml:
#create persistent volume
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: pv-vol
spec:
storageClassName: manual
capacity:
storage: 10Gi
accessModes:
- ReadWriteOnce
hostPath:
path: /opt/storage/app
#create persistent volume clame
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: app-pv-claim
spec:
storageClassName: manual
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 10Gi
#create Deployment
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: app-deployment
spec:
replicas: 1
selector:
matchLabels:
deploy: app
template:
metadata:
labels:
deploy: app
spec:
hostname: app
hostNetwork: false
containers:
- name: app
image: 192.168.10.10:2021/project/app:latest
volumeMounts:
- mountPath: /opt/app
name: project-volume
volumes:
- name: project-volume
persistentVolumeClaim:
claimName: app-pv-claim

Answer 1

Due to information gaps, I am writing a general answer.
First of all you should know:
HostPath volumes present many security risks, and it is a best practice to avoid the use of HostPaths when possible. When a HostPath volume must be used, it should be scoped to only the required file or directory, and mounted as ReadOnly.
But the use of hostPath also offers a powerful escape hatch for some applications.
If you still want to use it, firstly you should check if both pods (the one that created the data and the second one that want to access the data) are on the same node. The following command will show you that.
kubectl get pods -o wide
All data created by any of pods should stay in hostPath directory and be available for every pod as long as they are running on the same node.
See also this documentation about hostPath.