klud/nfs-server-alpine repository overview

⁠DEPRECATED IN FAVOR OF itsthenetwork/nfs-server-alpine⁠

⁠Tags

• latest, amd64 (Dockerfile)⁠
• armhf (Dockerfile)⁠
• aarch64 (Dockerfile)⁠

⁠Image based on:

itsthenetwork/nfs-server-alpine⁠

⁠Overview

A handy NFS Server image comprising of:

• Alpine Linux⁠ Edge. Alpine Linux is a security-oriented, lightweight Linux distribution based on musl libc⁠ (v1.1.15) and BusyBox⁠.
• NFS v4 only, over TCP on port 2049.

When run, this container will make whatever directory is specified by the environment variable SHARED_DIRECTORY available to NFS v4 clients.

docker run -d \
--name nfs \
--privileged \
-v /some/where/fileshare:/nfsshare \
-e SHARED_DIRECTORY=/nfsshare \
klud/nfs-server-alpine:latest

Add --net=host or -p 2049:2049 to make the shares externally accessible via the host networking stack. This isn't necessary if using Rancher⁠ or linking containers in some other way.

Due to the fsid=0 parameter set in the /etc/exports file, there's no need to specify the folder name when mounting from a client. For example, this works fine even though the folder being mounted and shared is /nfsshare:

sudo mount -v <NFS Server IP>:/ /some/where/here

To be a little more explicit:

sudo mount -v -o vers=4,loud <NFS Server IP>:/ /some/where/here

To unmount:

sudo umount /some/where/here

The exports file contains these parameters:

*(rw,fsid=0,async,no_subtree_check,no_auth_nlm,insecure,no_root_squash)

Note that the showmount command won't work against the server as rpcbind isn't running.

⁠RancherOS

You may need to do this to get things working:

sudo ros service enable kernel-headers
sudo ros service up kernel-headers

RancherOS also used overlayfs for Docker so please read the next section.

⁠OverlayFS

OverlayFS does not support NFS export so please volume mount into your NFS container from an alternative (hopefully one is available).

On RancherOS the /home, /media and /mnt file systems are good choices as these are ext4.

⁠Other OS's

You may need to ensure the nfs and nfsd kernel modules are loaded by running modprobe nfs nfsd.

⁠Mounting Within a Container

The container requires the SYS_ADMIN capability, or, less securely, to be run in privileged mode.

⁠What Good Looks Like

A successful server start should produce log output like this:

Starting Confd population of files...
confd 0.12.0-dev
2017-05-17T09:24:57Z ffcbba1623e6 /usr/bin/confd[13]: INFO Backend set to env
2017-05-17T09:24:57Z ffcbba1623e6 /usr/bin/confd[13]: INFO Starting confd
2017-05-17T09:24:57Z ffcbba1623e6 /usr/bin/confd[13]: INFO Backend nodes set to 
2017-05-17T09:24:57Z ffcbba1623e6 /usr/bin/confd[13]: INFO /etc/exports has md5sum 4f1bb7b2412ce5952ecb5ec22d8ed99d should be 92cc8fa446eef0e167648be03aba09e5
2017-05-17T09:24:57Z ffcbba1623e6 /usr/bin/confd[13]: INFO Target config /etc/exports out of sync
2017-05-17T09:24:57Z ffcbba1623e6 /usr/bin/confd[13]: INFO Target config /etc/exports has been updated

Displaying /etc/exports contents...
/nfsshare *(rw,fsid=0,async,no_subtree_check,no_auth_nlm,insecure,no_root_squash)

Starting NFS in the background...
rpc.nfsd: knfsd is currently down
rpc.nfsd: Writing version string to kernel: -2 -3 +4 
rpc.nfsd: Created AF_INET TCP socket.
rpc.nfsd: Created AF_INET6 TCP socket.
Exporting File System...
exporting *:/nfsshare
Starting Mountd in the background...