[lxc-users] Network does not start automatically on Debian Jessie and Stretch containers, works fine in Wheezy

[Anders Andersson]

On Mon, Apr 11, 2016 at 4:59 PM, Serge Hallyn <serge.hallyn at ubuntu.com> wrote:
> Quoting Anders Andersson (pipatron at gmail.com):
>> I have a seemingly trivial problem with Debian containers on a Debian
>> host, but I can't seem to figure out why it happens so I'm turning to
>> the professionals for help.
>>
>> I run a Debian Stretch (testing) server for my personal use at home.
>> It has been running a Debian Wheezy container for a long time, no
>> problems whatsoever, implying that my bridge is correctly set up, and
>> the corresponding LXC config for the container:
>>
>>  lxc.network.type = veth
>>  lxc.network.link = br0
>>  lxc.network.flags = up
>>
>> Now I want more containers, so I tried creating a Jessie container
>> using the following command:
>>
>>  lxc-create -t download -n deb8 -- -d debian -a amd64 -r jessie
>>  lxc-start -n deb8
>>
>> This fails to initialize the network inside the new container.
>>
>> To debug this, I tried creating three containers using these identical commands:
>>
>>  lxc-create -t download -n deb7 -- -d debian -a amd64 -r wheezy
>>  lxc-create -t download -n deb8 -- -d debian -a amd64 -r jessie
>>  lxc-create -t download -n deb9 -- -d debian -a amd64 -r stretch
>
> Can you show the process listing in the broken containers?

Sure, there is not much to show:

root at deb8:~# ps auxf
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
root        10  0.0  0.0  21868  3812 ?        S    16:22   0:00 /bin/bash
root        11  0.0  0.0  19068  2464 ?        R+   16:22   0:00  \_ ps auxf
root         1  0.0  0.0  27080  2052 ?        S    16:14   0:00 /sbin/init

deb9 looks the same.



> I'd assume the problem is that systemd is getting stuck due to cgroups
> not being sufficiently available.  In which case the answer should be
> to install lxcfs, or to run a kernel with cgroup namespaces available.

I'm not completely sure what cgoup namespaces means here, but the
output from my "lxc-checkconfig" shows (among other things):
Namespaces: enabled
Cgroup: enabled



> Which lxc and lxcfs versions do youhave installed?

lxc: 1.1.5
lxcfs: not installed

After installing lxcfs, my deb9 container works! It starts up a DHCP
client and gets an IP address from my server, and I can attach to it
and use for example journalctl.

The debian 8 (jessie) container still does not work, but my immediate
goal was to get a debian 9 container so my problem is currently
solved.

Thanks for the hint! Perhaps the lxc package in debian should
recommend or at least suggest lxcfs, since it seems necessary to run a
debian stretch container on a debian stretch host.

// Anders