[lxc-users] proc not available inside unprivileged container

[Serge E. Hallyn]

On Thu, Jun 06, 2019 at 07:55:04PM +0200, Dr. Todor Dimitrov wrote:
> Hello,
> 
> we have an unprivileged container on LXC 2.1.1, which starts without any errors. The /proc system is however not available/mounted:
> 
> ...
> drwxr-xr-x    2 root     root          1024 Jul 19  2018 proc

...  This doesn't show me anything.  Can you show the result of:

mountpoint /proc
ls -l /proc

?

> ...
> dr-xr-xr-x   12 nobody   nogroup          0 Jun  6 17:13 sys
> ...
> 
> /sys on the other hand is present. The network seems to work, we can login with lxc-console, only commands which rely on /proc are non-functional, e.g. mount, ps, etc. The configuration file contains the following line:
> 
> lxc.mount.auto = cgroup:rw proc:rw sys:rw
> 
> The same configuration runs without any problems on a similar system using the same kernel version (3.12.59). Suspicious in the logs are the following entries:
> 
>       lxc-start qivicon 20190606172753.696 DEBUG    console - console.c:lxc_console_peer_default:450 - process does not have a controlling terminal
>       lxc-start qivicon 20190606172753.848 INFO     lxc_utils - utils.c:lxc_mount_proc_if_needed:1758 - I am 13379, /proc/self points to "1"
>       lxc-start qivicon 20190606172753.848 INFO     lxc_utils - utils.c:lxc_mount_proc_if_needed:1780 - mounted /proc in container for security transition
> 
> On the "working" system, we see:
> 
>       lxc-start qivicon 20190606182855.698 DEBUG    console - console.c:lxc_console_peer_default:450 - process does not have a controlling terminal
>       lxc-start qivicon 20190606182855.731 INFO     lxc_utils - utils.c:lxc_mount_proc_if_needed:1758 - I am 1, /proc/self points to "1"
> 
> 
> Do you have any ideas what the cause of the problem might be?

Please post the full logs resulting from lxc-start -l debug -o output_file

-serge