Question 85015 in Docker Question posted in
The official documentation can be found here.

why the mountpoint in container can't been seen in host – Docker

I want do some device initiation by using Daemonset(K8s resource).

Actually the deivce has been formated(inside container) and mounted(inside container) successfully to a container path /hostmnt/lvpmem/ which is mapped of /mnt/ which is a host path.

mountpoint works fine in container

[root@driver-hm4ll /]
#mountpoint /hostmnt/lvpmem/
/hostmnt/lvpmem/ is a mountpoint

but mountpoint works wrong in host env

[root@host ~]# mountpoint  /mnt/lvpmem/
/mnt/lvpmem/ is not a mountpoint

Also the data I write in container under /hostmnt/lvpmem/ can’t been seen under /mnt/lvpmem/ in host env.

How can I mount the device so that both host and container can see it ?
Also, if container is destroyed does the mount relation also be destroyed ? I have no idea about umounting the device in host env if mount relation can’t be seen.
Some opensource project use nsenter in container to run such format/mount command does it help ?

Tags:

2

Answers


  1. Chosen as BEST ANSWER
    0

    Mount point seen in container is just the snapshot when container start. My solution:

    1. Enable hostPID for pod and use nsenter to mount on host
    2. Restart container itself by using exit then the mount point can be seen in new container

  2. 0
    • add /mnt as a volume to pod on directory /hostmnt. So that whatever being written under /hostmnt directory (insisde the container) will be seen on host under directory /mnt .
    Example of a pod with hostpath :

apiVersion: v1
kind: Pod
metadata:
  name: test-pd
spec:
  containers:
  - image: k8s.gcr.io/test-webserver
    name: test-container
    volumeMounts:
    - mountPath: /hostmnt
      name: test-volume
  volumes:
  - name: test-volume
    hostPath:
      # directory location on host
      path: /mnt
      # this field is optional
      type: Directory
    Login or Signup to reply.
Please signup or login to give your own answer.

Back To Top
Search