[lxc-devel] Detecting if you are running in a container

[david at lang.hm]

On Tue, 11 Oct 2011, Eric W. Biederman wrote:

> david at lang.hm writes:
>
>> On Tue, 11 Oct 2011, Eric W. Biederman wrote:
>>
>>> Theodore Tso <tytso at MIT.EDU> writes:
>>>
>>>> On Oct 11, 2011, at 2:42 AM, Eric W. Biederman wrote:
>>>>
>>> I admit for a lot of test cases that it makes sense not to use a full
>>> set of userspace daemons.  At the same time there is not particularly
>>> good reason to have a design that doesn't allow you to run a full
>>> userspace.
>>
>> how do you share the display between all the different containers if they are
>> trying to run the X server?
>
> Either X does not start because the hardware it needs is not present or
> Xnest or similar gets started.
>
>> how do you avoid all the containers binding to the same port on the default IP
>> address?
>
> Network namespaces.
>
>> how do you arbitrate dbus across the containers.
>
> Why should you?

because the containers are simulating different machines, and dbus doesn't 
work arcross different machines.

>> when a new USB device gets plugged in, which container gets control of
>> it?
>
> None of them.  Although today they may all get the uevent.  None of the
> containers should have permission to call mknod to mess with it.

why would the software inside a container not have the rights to do a 
mknod inside the container?

>> there are a LOT of hard questions when you start talking about running a full
>> system inside a container that do not apply for other use of
>> containers.
>
> Not really mostly the answer is that you say no.
>
> Eric
>

David Lang