[buildd-tools-devel] schroot development: feature removal and addition

[Raphael Hertzog]

Hi Roger,

On Mon, 17 Aug 2015, Roger Leigh wrote:
> I think union filesystems have usage from bug reports, but no idea how
> popular they are in practice. 

I use them all the time and I also use them for Kali Linux build daemons.
It's the best solution if you're not yet ready to rely on btrfs IMO
and they work rather well.

It's definitely a feature that we should keep. BTW, the precise technology
(aufs, overlayfs, overlay) doesn't matter much and we should really be
able to say "union-type=auto" and let schroot use what's available. Is
that something that you could implemement (if yes I'll gladly open you
a github ticket)?

> With regard to feature addition, I'll look at (re-)starting doing a bit of
> work on the 1.7.x (master) branch.  Are there any particularly important
> features you would like to see adding, or any particularly glaring defects?

See above for a first feature.

Then schroot needs some love with respect to management of mount points
and their possible private/slave/shared status (cf
https://www.kernel.org/doc/Documentation/filesystems/sharedsubtree.txt)

Some bugs related to this:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=786566
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=794828
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=749897

This is not specific to systemd although it contributes to make it happen
since mounted filesystems are tagged as shared by default with systemd
(but you can do that with sysvinit as well).

We should possibly tag the chroot's session root mount point as
"unbindable" so that it doesn't get re-mounted somewhere else as part of
some shared mount point in a parent directories. Just a thought at this
point and I made no test for this.

> I know there are some important issues from the Debian and Ubuntu bugs, but
> I lack the background to meaningfully test and review any patches--if anyone
> would like to open PRs for these with tested patches, I'll be happy to apply
> them.   (I am in the process of setting up some VMs specifically for
> properly testing schroot, but please bear with me until they are sorted
> out.)

Quick question, are you still reviewing/considering the Debian bugs as part
of your issues list? Or shall we open github tickets for all the bugs
that we believe are upstream bugs?

> I saw Raphael had done some reorganisation of the Debian schroot.git; thanks
> for doing that.  If there's anything you need or want from me, please shout.
> Do you want the debian/ directory removing from the upstream master and/or
> schroot-1.6 branches to make your work easier?  I was planning to do so at
> some point, but I'll do whatever you prefer here.

Yes, please drop the debian directories. They have already diverged
between Debian and your git repository and it will avoid us to have to
filter your upstream tarball when we import it on our side.



> 
> 
> Regards,
> Roger
> 

-- 
Raphaël Hertzog ◈ Debian Developer

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