[Lxc-users] Gathering information about containers - from inside and from outside

[Daniel Lezcano]

On 07/18/2010 11:48 AM, Clemens Perz wrote:
> Hi,
>
> I was just searching my system for any status information about my
> running containers, cause I want to start writing a script that collects
> and displays this.
>
> So doing a while on /var/lib/lxc as a starting point, run lxc-info on
> each, find out which one is running, examine its cgroup and so on.

You should look for the abstract socket "@/var/lib/lxc/<name>/command" 
too. This socket exists when the container is running. The container can 
run without a previous creation, hence you won't find it in 
/var/lib/lxc. These containers are called "volatile containers".

> I have three macvlan containers running, but funny enough lsmod shows
> that the macvlan module is not used.

Do you mean the refcount is 0 ? or the module is not visible ?

> I cant find any entries in proc or
> sys that would tell me anything about the existance of the network
> interfaces for the containers.

You can access these informations via /proc. Let's say on the host, the 
init pid is 1234, then you can look at:

cat /proc/1234/root/proc/1/net/dev

But you won't be able to get the IP address.

At present, there is some work to make possible to 'attach' a container 
but it is not yet merged in the upstream kernel. With the attach, it 
will be possible to gather all the container information.

> Can I find them at all? Could lxc-info be
> extended to be verbose and tell you more in a parseable way?

Yes, absolutely. that would be nice to extend the lxc-info :)

> I have adapted a similar thing I wrote for vserver and this is how it
> might look like:
>
> Container   Boot    Status  M-PID   IP              Load
> --------------------------------------------------------------------
> CVS01       AUTO    UP      40003   10.100.100.11   0.00  0.00  0.00
> MAILE       man     down    --      10.100.100.12   --
> CVS02       AUTO    UP      105     10.100.100.13   0.00  0.00  0.00
>
> Guess the load might be an idea for the future :)

yep :)

Thanks
   -- Daniel