Comment 52 for bug 1684481

St├ęphane Graber (stgraber) wrote :

We're looking at changing lxc to show /dev/ptmx as a real file rather than symlink. This is however not particularly easy because:
 - It can't be a bind-mount from the host (or it will interact with the host's devpts)
 - It can't be a straight mknod (because that's not allowed in unprivileged containers)

So we're looking at re-ordering the liblxc code to setup a bind-mount from /dev/pts/ptmx to /dev/ptmx INSIDE the container, which should work.

That part of the kernel has changed quite a bit, so making sure we don't break things for supported kernels (2.6.32 or higher) is going to be a bit tricky.

Note that there is nothing wrong with /dev/ptmx being a symlink to /dev/pts/ptmx and I'd argue it's actually "more right" than having it be a device node. But since that's not what udev/devtmpfs do, we probably should mimic the host's behavior.