Re: Guix Docker image inflation

[zimoun <zimon.toutoune@gmail.com>]

Hi Chris,

On Sat, 30 May 2020 at 01:31, Chris Marusich <cmmarusich@gmail.com> wrote:

> Could it be that you are accumulating layers without bound?
>
> https://developers.redhat.com/blog/2016/03/09/more-about-docker-images-size/
>
> Since Docker images are built up of immutable layers, if you build your
> image from an existing base image, I'm not sure that it's possible to
> produce a new image that is smaller than the base image.  Basically,
> even if you run "guix gc" to remove dead store items, they will still
> exist on a prior layer, so the size of the new image won't decrease.
> And since you're installing new things, the size will actually increase.
> If you repeat this process by using the new image as an input for yet
> another build, I think you will accumulate layers and storage space
> without bound.

Thank you for the explanation.  The issue is these layers.  When I
wrote [1], it was not clear for me because I am not enough familiar
with Docker, but with your explanations, it is clear now. :-)

[1] http://issues.guix.gnu.org/41607#1


> FYI, Guix itself can build Docker images from scratch - no base image
> required!  It can even build a Docker image of a full-blown Guix System
> from scratch.  Sorry if you already knew that - I just wanted to point
> it out in case you didn't!

I think the idea is to use GitlabCI to build the Docker images
containing Guix materials.  And AFAIK, GitlabCI does not provide Guix
related tools, isn't it?  I mean there is no gitlab-runner able to run
guix-daemon.  If I remember well, we discussed about this topic at
FOSDEM, it should be awesome. :-)


Cheers,
simon