Upcoming CI changes - transition to VM based CI

[Ben Cooksley]

On Wed, Jun 4, 2025 at 8:17 AM Albert Astals Cid <aacid at kde.org> wrote:

> El dimarts, 3 de juny del 2025, a les 11:42:08 (Hora d’estiu d’Europa
> central), Ben Cooksley va escriure:
> > On Tue, Jun 3, 2025 at 9:03 AM Albert Astals Cid <aacid at kde.org> wrote:
> > > El dilluns, 2 de juny del 2025, a les 13:39:21 (Hora d’estiu d’Europa
> > >
> > > central), Ben Cooksley va escriure:
> > > > Hi all,
> > > >
> > > > For some time now we have had a variety of issues with our
> Docker/Podman
> > > > based CI builds. These have included the lack of GUI test support on
> > > > Windows, periodic crashes on FreeBSD, poor IO performance of Windows
> > > > builds, issues supporting builds for Flatpak and Snaps and inability
> to
> > > > support either builds or tests where elevated privileges or system
> > >
> > > session
> > >
> > > > resources are needed.
> > > >
> > > > In addition to this we've had issues where Linux CI builds have the
> > > > capability to trigger OOM events on the CI hosts, which in turn takes
> > > > out
> > > > Windows and (less often) FreeBSD builders. While this does not occur
> too
> > > > often, it does happen from time to time and eventually negatively
> > > > impacts
> > > > the build queue for those platforms.
> > > >
> > > > The need to have dedicated VMs for FreeBSD and Windows on our
> builders
> > >
> > > also
> > >
> > > > makes setting up of a CI build node for KDE software a more
> complicated
> > >
> > > and
> > >
> > > > time intensive task than it otherwise needs to be (and means that the
> > > > amount of systems to care for increases by 3 for every CI node we
> add).
> > > >
> > > > While individually relatively minor, together these issues more than
> > > > justify making a significant change to the way we run our CI system
> - in
> > > > this case transitioning from container based builds to VM based
> builds.
> > > >
> > > > These builds will still take place on dedicated hardware that we
> > > > control,
> > > > however instead of taking place within a container (managed by
> Podman on
> > > > Linux and FreeBSD, or Docker on Windows) they will instead take place
> > > > within a VM using a copy-on-write disk image.
> > > > VM based builds will unfortunately take a little longer to start (it
> > >
> > > takes
> > >
> > > > ~10 seconds for a VM from any of Linux, FreeBSD or Windows to boot
> on my
> > > > personal system) however the benefits we gain should more than
> outweigh
> > > > this small downside.
> > > >
> > > > This has been under development for the past couple of weeks and is
> now
> > > > reaching the point where the only remaining steps are to get it
> > >
> > > integrated
> > >
> > > > with the Gitlab CI agent (gitlab-runner) for which prototype code is
> > > > already in place, and complete porting of our images over. Once that
> > > > happens a complete rebuild of all of our builders will be swiftly
> > > > undertaken to transition them completely over to the new VM based
> > > > infrastructure.
> > > >
> > > > Specs wise, at this time it is planned for each spawned standard VM
> to
> > > > be
> > > > provided with 2/3's of the system CPU cores (so 12 cores), 16GB RAM
> and
> > > > 100GB of disk space (although some of that will be occupied by the
> > > > system
> > > > image - approximately 10GB for standard Linux builds and ~30GB or so
> for
> > > > Windows builds). There will be a higher resource tier available for
> > >
> > > certain
> > >
> > > > builds however that will be on request only and would need to be
> > >
> > > justified
> > >
> > > > (such as Craft needing to build QtWebEngine).
> > > >
> > > > As launching VMs is not the most efficient approach for all
> workloads,
> > > > limited support for running Docker containers will be preserved,
> however
> > > > this support is primarily intended for running linters, sanity checks
> > > > and
> > > > website builds, and is not intended for running general CI/CD builds.
> > > >
> > > > The tooling used by the CI nodes to run VMs is something that should
> be
> > > > fairly trivial for people to run on their own local system should
> they
> > >
> > > wish
> > >
> > > > to run any of those images (say for FreeBSD or Android), although you
> > >
> > > will
> > >
> > > > need to setup libvirt yourself (SUSE has very good instructions for
> > > > this,
> > > > Debian less so as their instructions lack installing the packages
> needed
> > >
> > > to
> > >
> > > > provide UEFI and TPM support). The tooling itself was merged this
> > > > evening
> > > > to sysadmin/ci-images (vm-common/ folder) and can be used with the VM
> > > > images found at https://storage.kde.org/vm-images/
> > > >
> > > > There is however one downside to this - Qt 5 support.
> > > >
> > > > Over the past few months distributions have been steadily removing
> > >
> > > packages
> > >
> > > > and other supporting infrastructure needed to keep Qt 5 builds
> alive. In
> > > > the case of Windows, support for the entire Qt 5 tree has been
> > >
> > > unmaintained
> > >
> > > > for some time. For FreeBSD and SUSE a significant number of packages
> > > > have
> > > > been removed - which in the case of SUSE also includes packages
> needed
> > > > to
> > > > support the building of KJS.  Accordingly, because builds of
> Frameworks
> > >
> > > are
> > >
> > > > a first stepping stone to support building anything else, it will
> not be
> > > > possible for us to produce Qt 5 based VM build images for any of the
> 3
> > > > platforms.
> > > >
> > > > We will therefore have to remove Qt 5 support from the CI system with
> > > > the
> > > > transition to VM based CI.
> > >
> > > From previous discussions I had the impression this was only for things
> > > that
> > > wanted to create packages and not for "want to have CI to compile/run
> > > tests".
> > >
> > > Can you confirm you are proposng a total annihilation of Qt5 support in
> > > our
> > > CI?
> >
> > At the time we had that discussion it was still possible to build some of
> > the Qt 5 images, however that is no longer the case - all of them now
> fail
> > to build.
> >
> > In the case of the suse-qt515 image, the removal of libpcre in SUSE means
> > it is no longer possible to build KJS.
> > Consequently, we're no longer able to build all Frameworks (making 'kf5'
> > branch CI for Frameworks non-functional) so there isn't much point in
> > looking further to support Qt 5 on Linux.
> >
> > For FreeBSD the story is much the same as SUSE - packages are being
> removed
> > as apps upgrade to Qt 6 and the Qt 5 version of libraries becomes surplus
> > to requirements.
> >
> > For Windows the continued operation of that CI has only been possible
> > because our existing images are still around - new ones cannot be built.
> > That has been the case for a significant amount of time now, and it is
> not
> > worth the investment to fix it as everyone who works on Windows has moved
> > on to Qt 6.
> >
> > In essence there is little we can do to keep this alive - distributions
> are
> > removing support so we must follow suit.
> >
> > The correct course of action is to accelerate the porting of the
> remaining
> > applications, not to delay and keep Qt 5 alive.
>
> As Nico said, we can just not build KJS/KHTML and then give the projects
> that
> still use Qt5 a reasonable timeframe for them to port to Qt6, e.g. until
> the
> end of the year, not until the end of the month.
>

Depending on how projects have written their .kde-ci.yml files, this will
either work fine or fail so a degree of rewriting of those files may be
needed.
But it could be tried - it is very much keeping something on true last gasp
life support though and isn't going to be pleasant to maintain as things
are going to keep disappearing.

My concern is that if we keep pushing out terminating support those
projects will just keep deferring their porting.
Note that Frameworks 6 released in Feb 2024, so they've had 15 months so
far to port which is a pretty reasonable amount of time.

Can we at least go through and remove Qt 5 CI from anything that has ported
over and is running both currently?
Given we're now unable to build them we should probably declare KHTML and
KJS unmaintained and archive them as well.


>
> Cheers,
>   Albert
>

Regards,
Ben


>
> >
> > > Cheers,
> > >
> > >   Albert
> >
> > Regards,
> > Ben
> >
> > > > Please let me know if there are any questions on the above.
> > > >
> > > > Thanks,
> > > > Ben
>
>
>
>
>
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