Sharing a containers fuse mount with another container

LXD
1

I already tried creating a storage volume and giving that to both containers, but it stays empty. The crux is, that the container is mounting a fuse filesystem only it can do and I want to share the resulting dir with another container. Is there a way to share this mount with another container using lxd’s capabilities or am I forced to use nfs or similar?

~# lsb_release -ds
Ubuntu 22.04.5 LTS
~# snap list lxd
Name  Version      Rev    Tracking       Publisher   Notes
lxd   6.3-a85d6a5  33246  latest/stable  canonical✓  -
2

Ah, in docker you seem to be able to define mount propagation, which seems to be possible in LXD device disk “propagation”. Trying it out

1 Like
3

Ok, this doesn’t seem to work or I do something wrong…

I tried in the device: propagation: shared and propagation: rshared as well as with or without recursive: "true" on the mountpoint folder or a subfolder - no dice.

This has also been asked back then in the linuxcontainers forum with no further resolution.

Easy to replicate steps:

In a container config set the disk device with propagation:

devices:
  bind-fuse:
    path: /mnt/fuse
    propagation: rshared
    required: "true"
    source: /mnt/fuse
    type: disk

In the container test it with a tmpfs mount (I assume tmpfs is a viable option to replicate the issue as easy as possible):

~# mount -t tmpfs tmpfs /mnt/fuse
~# touch /mnt/fuse/foo
~# ls -l /mnt/fuse/
total 0
-rw-r--r-- 1 root root 0 Jun  6 13:08 foo

But not visible on the host:

~# ls -l /mnt/fuse/
total 0

I’ve also tried a subfolder in this mountpoint with help of recursive: "true" - still no dice.

The container is an unprivileged container with ubuntu 22.04 as well