This adds a device of type disk to <code><container-name></code>. The <code>source</code> is the host's file path, and <code>path</code> is the path in the container.
Do to how permissioning works on unprivileged containers, the mount permissions have to be changed on the host system. Firstly you have to know what gid/uid offset LXD is using for it's containers. In the case of NixNet's setup, the containers are on an offset of 100000, which means the root user in the container has the permissions of user 100000 on the host system.
The next step is to get the uid/gid of the user that needs to access the mounted files in the container. To get this, simply run <code>id <user></code> on the user.