lxc-start exits success on failure when non-root in daemon mode

Another (likely related) issue, after using sudo to start the container, observe:

$ lxc-ls
lv1
$ sudo lxc-start -n lv1 -d
$ lxc-ls
lv1
/usr/bin/lxc-ls: line 35: cd: /sys/fs/cgroup/cpuset///lxc: Permission denied
ls: cannot access lv1: No such file or directory
$ sudo lxc-ls
lv1
lv1
$ sudo lxc-list
RUNNING
  lv1

STOPPED

So, as it is now after starting the container 'sudo lxxc-ls' shows 2 containers, but 'lxc-ls' (without sudo) shows annoying messages.

Indeed that should be fixed. Thanks for the bug report.

Ok, I'm actually not sure what we should do about this.

'-d' doesn't just mean don't show a console, it means daemonize. It does this by calling daemon(3), which forks(), lets the child continue, and exits success.

We could toss extra checks in before the call to daemon(3) to check for privilege, but there are plenty of other reasons why the start could fail.

So it seems we can do one of two things:

  1. rewrite lxc-start so that it manually forks and waits for a message from the lxc monitor saying the container started, and only then exit

  2. tell users that 'lxc-start -d' provides no information about the success of starting the container, and that if you care, you should call something like

   lxc-wait -n container -s RUNNING

     after the lxc-start to make sure it succeeded.

This bug was fixed in the package lxc - 0.8.0~rc1-4ubuntu26

---------------
lxc (0.8.0~rc1-4ubuntu26) quantal; urgency=low

  * 0100-template-cleanup-cache: clean up template cache if interrupted
    during build. (LP: #1037331)
  * 0101-template-empty-apt-cache: do an apt-cache clean after creating
    a new cache. (LP: #1037626)
  * 0102-lxc-start-d-check-privs: exit early (with failure) if starting a
    daemonized container with insufficient privilege. (LP: #918327)
  * 0103-make-rootfs-location-optional: allow custom location for a
    container rootfs to be specified. (LP: #1019398)
 -- Serge Hallyn <email address hidden> Fri, 17 Aug 2012 09:44:02 -0500