Re: Guix Docker image inflation

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

Dear Stephen,

On Sun, 31 May 2020 at 19:51, Stephen Scheck <singularsyntax@gmail.com> wrote:

> But I'm now starting to doubt my whole approach because it seems like
> there are some fundamental GC problems with running a live Guix system
> inside a container.

I do not think it is "some fundamental GC problems with running a live
Guix system inside a container" but it is a fundamental Docker
filesystem design which is incompatible with your approach.  As I have
tried to show, the issue is:

$ CONTAINER=`docker run --detach --tty --privileged image0`
$ docker exec --interactive --tty $CONTAINER /bin/sh
/ # dd if=/dev/urandom of=/data1 bs=1234567 count=1024
$ HASH=`docker commit $CONTAINER` && docker tag $HASH image1

$ CONTAINER=`docker run --detach --tty --privileged image1`
$ docker exec --interactive --tty $CONTAINER /bin/sh
/ # rm /data1
/ # dd if=/dev/urandom of=/data2 bs=1234567 count=1024
$ HASH=`docker commit $CONTAINER` && docker tag $HASH image2

$ CONTAINER=`docker run --detach --tty --privileged image2`
$ docker exec --interactive --tty $CONTAINER /bin/sh
/ # rm /data2
/ # dd if=/dev/urandom of=/data3 bs=1234567 count=1024
$ HASH=`docker commit $CONTAINER` && docker tag $HASH image3

etc.

And all the resulting images are bigger and bigger.  Do I misread something?

Maybe "docker export | docker import" should help to keep the size
"reasonable" even if I am not convinced...


Well, thank you for raising the issue, because I have learnt
interesting stuff about Docker. :-)
And I do not have yet something concrete to say about your initial issue, sorry.


All the best,
simon