How to share a docker network between LXC containers

[WillSnake]

Hello!
I don't have a lot of experience with Proxmox, but I was wondering if it's possible to share a docker network created with a docker-compose.yml between several LXC containers.
I'm not familiar with docker swarm, that's why I want to know if this is possible before trying to use it.
I know that LXC containers share resources from the host machine, that's why I was wondering if I can mount the /var/run/docker.sock into the LXC containers.
So far I've tried to mount the /var/run/docker.sock like this:

On the Proxmox host, create a new group for Docker:

groupadd -g 1000 docker_sock

Change the ownership of the Docker socket:

chown root:docker_sock /var/run/docker.sock

Modify the permissions of the Docker socket:

chmod 660 /var/run/docker.sock

Edit the LXC container's configuration file and add the following lines:

lxc.mount.entry: /var/run/docker.sock mnt/docker.sock none bind,create=file
lxc.idmap: u 0 100000 65536
lxc.idmap: g 0 100000 65536
lxc.idmap: g 0 100000 1000
lxc.idmap: g 1000 1000 1
lxc.idmap: g 65534 165534 1

And after these changes I got stuck, because I'm having issues with the permissions on the file mounted on mnt/docker.sock because I tried to create a symlink to /var/run/docker.sock inside the container.

Does anybody know if this is possible?

 

[louie1961]

the only way I can think to make this happen is if your docker containers connect to the same network your LXC containers are on via a MACVLAN set up in docker. Without a macvlan or ipvlan docker network, the normal brisdge networks won't allow it.

 

[WillSnake]

the only way I can think to make this happen is if your docker containers connect to the same network your LXC containers are on via a MACVLAN set up in docker. Without a macvlan or ipvlan docker network, the normal brisdge networks won't allow it.

Interesting. That's a good idea, I can give it a try. I'll let you know if I can make it work.
Thanks louie1961!