How to mount the LXD socket from the host to a LXD container?

1

I have got a LXD host (Snap) and a LXD container with LXD installed (Snap). I would like to have the LXD container access the LXD socket on the host machine. I want to do this out of the same reasoning I have described with this topic Topic 1650. Based on the solution provided for Docker I tried to derive a solution for LXD but it does not work.

Is there a way of getting this to work?

2

What is your lxc config device command for the socket?
LXD 3.4+ has additional options that should make it easy to share the socket to the container.

3

I use a Python script that starts the LXD container and does all the magic by the use of the pylxd==2.2.7 package.

The socket I am trying to access on the host is;

$ ls -lah /var/snap/lxd/common/lxd/unix.socket
srw-rw---- 1 root lxd 0 Sep  5 07:10 /var/snap/lxd/common/lxd/unix.socket

File permissions look okay to me…

The below is the JSON I use with pylxd.

{'lxd': {'path': '/mnt/lxd.sock', 'source': '/var/snap/lxd/common/lxd/unix.socket', 'type': 'disk'}}

See https://pylxd.readthedocs.io/en/latest/containers.html#container-attributes for respective docs.

I believe this equates to;

$ lxc config device add mycontainer lxd disk source=/var/snap/lxd/common/lxd/unix.socket path=/mnt/lxd.sock

The container’s boot init does;

touch /run/lxd.sock
mount --move/mnt/lxd.sock /run/lxd.sock
rm /mnt/lxd.sock

Before running any LXD commands, I set the LXD_SOCKET environment variable;

export LXD_SOCKET=/run/lxd.sock

When I then execute lxc ls, I get below error:

Error: Get http://unix.socket/1.0: dial unix "connect: no such file or directory"
4

Hi @quater,

Have a look at this blog post that works on LXD 3.4 or newer,

There is a typo in your commands (mount --move/mnt…) which is probably the cause of “no such file or directory”. That message means that the client did not encounter the specified socket file at all.

1 Like
5

Hi @simos,

Thank you very much for this brilliant blog post. Very descriptive! This resolves the problem!

Furthermore I will try to use the new proxy device for Docker instead of the approach that was used with Topic 1650.