centos - Mounting nfs shares inside docker container

Question

Does anyone know how to mount nfs share inside docker container with centos base image? I've tried this command:

mount server:/dir /mount/point

and got the next error:

mount.nfs: rpc.statd is not running but is required for remote locking.
mount.nfs: Either use '-o nolock' to keep locks local, or start statd.
mount.nfs: an incorrect mount option was specified

when I try to use it with -o nolock option, the error is:

mount.nfs: Operation not permitted

question from:https://stackoverflow.com/questions/39922161/mounting-nfs-shares-inside-docker-container

Answer 1

For using mount, you'll need the CAP_SYS_ADMIN capability, which is dropped by Docker when creating the container.

There are several solutions for this:

1. Start the container with the --cap-add sys_admin flag. This causes Docker to retain the CAP_SYS_ADMIN capability, which should allow you to mount a NFS share from within the container. This might be a security issue; do not do this in untrusted containers. [A previous version of this answer suggested using the --privileged=true to retain all capabilities, thanks to @earcam for the suggestion to use --cap-add instead].

2. Mount the NFS share on the host and pass it into the container as a host volume:

   you@host > mount server:/dir /path/to/mount/point
   you@host > docker run -v /path/to/mount/point:/path/to/mount/point
   

3. Use a Docker volume plugin (like the Netshare plugin) to directly mount the NFS share as a container volume:

   you@host > docker run 
     --volume-driver=nfs 
     -v server/dir:/path/to/mount/point 
     centos