Re: GSoC 2022 CI project idea proposal

On Tue, Feb 22, 2022 at 05:04:02PM +0100, Erik Skultety wrote: > So, we're offloading as much CI configuration/workflow stuff to lcitool > as possible. We can generate config files, install/update machines > (local or remote), dump Dockerfiles...we can't build and run those containers > locally. Instead, we have a CI helper script in libvirt repo which essentially > just wraps a Makefile which pulls a gitlab container for you and: > - gives you shell, or > - runs the build and tests > > I'm not sure how many people actually know we have that helper script let alone > use it. I've been playing with the idea that we could integrate what's done in > the Makefile to lcitool utilizing either the podman library [1] or the docker > library [2]. Apart from consolidating all CI services-related efforts to > lcitool the other benefit would be that we could gain the ability to run and > debug in a project-specific container also in other libvirt projects not just > main libvirt. > > So, I though this could be a nice project for GSoC. Ideas? I've been meaning to replace the make-based logic used for spawning local containers with a Python equivalent and get rid of ci/Makefile entirely. There was some progress last year, but I got sidetracked and never managed to finish the job. So obviously I'm in favor of doing more work in that area, especially if it's someone else doing it O:-) I'm not entirely convinced that requiring the use of lcitool for this task is necessarily the best idea though. Ideally, it should be possible for developers to reproduce and debug CI failures locally without having to clone a second repository. It's fine to require lcitool for tasks that are performed by maintainers, but casual contributors should find all they need in libvirt.git itself.

Another thing that has been bothering me is that neither 'ci/helper build' nor 'lcitool build' will actually perform the exact same build steps as the corresponding CI job, making them only mildly effective as debugging tools for CI failures. And of course each of these build recipes is maintained separately, so we have three similar but not quite identical scripts floating around.

Here's my (fairly hand-wavy :) idea of how things should work. Each project's repository should contain its build steps in the form of a ci/build script. The exact calling interface for this script will have to be determined, but based on existing usage at the very least we need to be able to specify the build type (regular, cross and with dependencies built from git) and target-specific settings (for example whether to skip building RPMs). So I can imagine the invocation looking something like $ TYPE=native RPMS=skip ci/build The build steps that currently live in the .native_build_job, .cross_build_job and .native_git_build_job templates in .gitlab-ci.yml will all be moved to the ci/build script. It shouldn't be necessary to alter them significantly in the process. With this interface defined, we can change 'lcitool manifest' so that the jobs it generates go from x86_64-almalinux-8-clang: extends: .native_build_job needs: - x86_64-almalinux-8-container variables: CC: clang NAME: almalinux-8 RPM: skip to x86_64-almalinux-8-clang: needs: - x86_64-almalinux-8-container script: - TYPE=native NAME=almalinux-8 CC=clang RPM=skip ci/build Of course it would still be possible to tell lcitool to use a custom template for the job instead, which might be necessary for setting up CI caching and the like. For simple cases though, you'd be able to use the default implementation. 'lcitool build' would also be changed so that it invokes the ci/build script in the project's repository. The last missing piece would then be to finish converting the ci/helper script that exists in libvirt to Python and make it so calling that entry point also ultimately in running the ci/build script. Of course having multiple copies of the ci/helper script and its logic for listing / running containers around is problematic because they would get out of sync over time... Perhaps we can maintain that script as part of libvirt-ci.git, and generate a local copy to be stored in each project's repository at the same time as other CI-related files such as Dockerfiles are generated? That sounds like it could work, but admittedly this is the fuzziest part of the entire plan :)