Re: apt2ostree - build ostree images of apt based distributions

[Will Manley <will williammanley net>]

On Wed, 12 Dec 2018, at 05:31, Daniel Drake wrote:
> On Tue, Dec 11, 2018 at 4:28 AM Colin Walters <walters verbum org> wrote:
> > Cool!  Would love if the deb-ostree-maintainers had a chance to look at this - there's a specific 
> > comparison here: https://github.com/stb-tester/apt2ostree#endless-ostree-builder-eob
>
> I imagine the deb-ostree-builder is lagging behind what we use
> internally, sorry about that.
> The comparison seems pretty accurate at a high level.
>
> However, in our updated internal version, we have stopped using
> debootstrap to set up the base filesystem tree. We got fed up of
> debootstrap acting differently from the real apt & dpkg
> implementations. We tried to fix it up, we tried to use multistrap too
> (same issue there), it just got too painful and instead of continually
> trying to adhere closer (and keep up with) apt, we decided to just use
> apt itself.
>
> If apt2ostree does not actually use apt for dep resolution, package
> installation etc, then I suspect it will ultimately face the same
> headaches.

Thanks for the heads-up.  Did you find the issues were more with apt dependency resolution and package 
selection, or more on the installation/dpkg side or both?

In apt2ostree the two sides are quite separate as the former is used to generate the lockfile and the latter 
uses the lockfile to know what to install.

> So we now use an alternative bootstrap tool, which is superior to
> debootstrap/multistrap/etc in the sense that 99% of the "business
> logic" is executed just by calling into apt. e.g. you'll notice it
> doesn't parse any control files, look up dependencies, etc.
>
> https://github.com/dbnicholson/apt-bootstrap

Thanks for that.  I'll have a play around with it.

To test apt2ostree I've been building the "same" images with apt2ostree and multistrap and doing a ostree 
diff to see the differences.  I've tried to add apt-bootstrap to the same test-harness[1] but I've not yet 
got it working.

[1]: 
https://github.com/stb-tester/apt2ostree/blob/8785feb2c35514f2156370c83a560cc3890d462c/tests/multistrap_compare/configure.py#L134-L155

Thanks

Will