Re: A few questions about guix containers

[Alex Sassmannshausen]

Hi Chris,

I wanted to thank you for your notes!  As always, my "I'll write a long
response with thoughts tomorrow" turned into "I'll write a response at
some point in the future."

I appreciated the pointers to the developments that have tentatively
happened.  Very interesting!

Cheers,
Alex


Christopher Baines writes:

> Alex Sassmannshausen <address@hidden> writes:
>
>> Hello,
>>
>> I'm trying to get to grips with Guix's container support.
>>
>> Specifically, I can create containerised system using
>> $ guix system container /path/to/sysconf.scm
>>
>> I should then be able to run commands in that container using
>> $ guix container exec PID CMD
>>
>> But here's the rub: how do I find the PID of the container launched
>> using 'guix system container'?
>
> I usually use htop or pgrep. I've been thinking recently about getting
> the script that launches the container to write the PID out somewhere,
> although I think you could also achieve this by sharing a directory
> between the container and the host system, and having a process in the
> container create a file in that directory. Then you could maybe use the
> PID that owns that shared file...
>
>> Also, I can relatively straight forwardly map network ports to guix
>> systems using
>> $ guix system vm /path/to/sysconf.scm
>> and qemu's -net user,hostfwd syntax
>>
>> Can I achieve similar mappings using 'guix system container'?
>>
>> Is anyone using containers to test complex networked services in system
>> configurations?
>
> So I've been using guix system container with some success for a while
> now, but I've been relying on this old patch I wrote to add shared
> network support, in the same way that guix environment can do it [1]
>
> 1: https://debbugs.gnu.org/cgi/bugreport.cgi?bug=28128
>
> I haven't given it enough attention, but recently Arun Isaac looks to
> have picked it up, so I'm hopeful that this functionality might be more
> widely available soon.
>
> One thing I'd love to see in this area is to be able to do networking
> similar to how libvirt/virt-manager does it. You can manage virtual
> networks there, and I'm not knowledgeable enough about networking to
> know what exactly it's doing, but I'd love to be able to run a
> container, and have it's network namespace it on a separate IP address
> on a virtual network. This would avoid port conflict problems with
> sharing localhost with the host system.
>
> Chris