[Lxc-users] Need simple configuration for embedded ARM LXC

[Daniel Lezcano]

On 04/15/2013 03:26 AM, Serge Hallyn wrote:
> Quoting Somnath Mitra (somnath.mitra at xockets.com):
>> On Fri, Apr 12, 2013 at 6:53 AM, Serge Hallyn <serge.hallyn at ubuntu.com>wrote:
>>
>>> Quoting Somnath Mitra (somnath.mitra at xockets.com):
>>>
>>  > Since the container rootfs is shared with host I am confused why it
>>> cannot
>>>> find lxc-init?
>>> Sounds like a compilation/packaging problem.  It works for me
>>> here, with ubuntu raring:
>>>
>>> cat > lxc.conf << EOF
>>> cat > lxc.conf << EOF
>>> lxc.utsname = beta
>>> lxc.network.type = empty
>>> lxc.rootfs = /
>>> lxc.aa_profile = unconfined
>>> EOF
>>> lxc.utsname = beta
>>> lxc.network.type = empty
>>> lxc.rootfs = /
>>> lxc.aa_profile = unconfined
>>> EOF
>>>
>>> sudo lxc-execute -n foobar -f lxc.conf -l info -o outout -- ps -ef
>>> UID        PID  PPID  C STIME TTY          TIME CMD
>>> root         1     0  0 08:46 pts/1    00:00:00
>>> /usr/lib/x86_64-linux-gnu/lxc/lxc-init -- ps -ef
>>> root         2     1  0 08:46 pts/1    00:00:00 ps -ef
>>>
>>> (an interactive shell doesn't work - just hangs, I don't use
>>> lxc-execute so always forget what is expect to work and what
>>> isn't)
>>>
>> Hangs for me too (on the embedded board). Can you comment on possible root
>> cause or workaround so we can investigate. My target application shall need
>> stdin, stdout and, possibly, stderr.
> Hi Daniel,
>
> can you comment on this by chance?  I frankly don't use lxc-execute, and
> I know you know of all sorts of special circumstances surrounding it...
> For me,
>
> 	cat > lxc.conf << EOF
> lxc.utsname = beta
> lxc.network.type = empty
> lxc.rootfs = /
> lxc.aa_profile = unconfined
> EOF
>
> 	lxc-execute -n foobar -f lxc.conf -- ps -ef
>
> works fine, while
>
> 	lxc-execute -n foobar -f lxc.donf -- /bin/sh
>
> hangs - some tty session thing?

At the first glance, yes.

Probably a SIGTTIN / SIGTTOU signal received. Something change with the
pid group/session leader ?

>
>>>> I have already checked that kernel is configured correctly using
>>>> lxc-checkconfig.
>>>>
>>>> Pls send a pointer to a simple working configuration for embedded
>>> systems.
>>>
>>> Take a look at src/lxc/execute.c:choose_init().  It will look for
>>> lxc-init in three places:
>>>
>>>         LXCINITDIR "/lxc/lxc-init"
>>>         /usr/lib/lxc/lxc-init
>>>         /sbin/lxc-init
>>>
>>> LXCINITDIR in ubuntu is /usr/lib/x86_64-linux-gnu, and lxc-init is in
>>> fact at /usr/lib/x86_64-linux-gnu/lxc/lxc-init.  (You can find your
>>> LXCINITDIR in config.log if you built your own lxc).  But the
>>> easier thing might be to just copy lxc-init into /sbin.
>>>
>> Yes I had put lxc-* binaries in /usr/bin. Putting them in /sbin solved it.
>>
>> Thanks,
>> SM.