`lxc-stop` does not support sending arbitrary signals.
By default, `lxc-stop -n <id>` would send `SIGPWR`.
The lxc driver was always sending `lxc-stop -n <id> -k`, which always
sends `SIGKILL`. In this case `lxc-start` returns an exit code of `0`,
regardless of what the container actually exited with.
Because of this we must send signals directly to the process when we
can.
Also need to set quiet mode on `lxc-start` otherwise it reports an error
on `stderr` when the container exits cleanly (ie, we didn't SIGKILL it),
this error is picked up in the container logs... and isn't really an
error.
Also cleaned up some potential races for waitblocked test.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
