kernelci/build.py: Add apply_patch_mbox method

[yurinnick]

Fixes kernelci/kernelci-api#307

Implement apply_patch_mbox method that downloads patch from mbox url into a temporary file and apply in to kernel tree

Test run logs:

kernelci-pipeline-notifier            | 07/31/2023 11:33:19 PM UTC [INFO] 2023-07-31 23:33:19.800845  HEAD          64c844bfe8ad32503e18af61  Running    -         checkout
kernelci-pipeline-tarball             | 07/31/2023 11:33:19 PM UTC [INFO] Updating repo for mainline
kernelci-pipeline-tarball             | From https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux
kernelci-pipeline-tarball             |  * branch                      HEAD       -> FETCH_HEAD
kernelci-pipeline-tarball             | From git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux
kernelci-pipeline-tarball             |  * branch                      HEAD       -> FETCH_HEAD
kernelci-pipeline-tarball             | HEAD is now at 5d0c230f1de8 Linux 6.5-rc4
kernelci-pipeline-tarball             | 07/31/2023 11:33:27 PM UTC [INFO] Repo updated
kernelci-pipeline-tarball             | 07/31/2023 11:33:27 PM UTC [INFO] Applying patch to the repo, patch mbox url: https://patchwork.kernel.org/project/linux-hardening/patch/20230726231139.never.601-kees@kernel
.org/mbox/
kernelci-pipeline-tarball             | 07/31/2023 11:33:28 PM UTC [INFO] Making tarball linux-mainline-master-v6.5-rc4-1-g66f6b7deab6b.tar.gz
kernelci-pipeline-tarball             | 07/31/2023 11:33:28 PM UTC [INFO] set -e
kernelci-pipeline-tarball             | cd /home/kernelci/data/src/linux
kernelci-pipeline-tarball             | git archive --format=tar --prefix=linux-mainline-master-v6.5-rc4-1-g66f6b7deab6b/ HEAD | gzip > ../../output/linux-mainline-master-v6.5-rc4-1-g66f6b7deab6b.tar.gz
kernelci-pipeline-tarball             |
kernelci-pipeline-tarball             |
kernelci-pipeline-tarball             | 07/31/2023 11:33:55 PM UTC [INFO] Tarball created

[gctucker]

The issue right now is that kernelci.build is not used by the new API & Pipeline. I think this is going a bit too fast, see my question on the issue kernelci/kernelci-api#307 as the first part is still missing - namely, how to connect Patchwork with the API.

Sorry, got that wrong. I see it's just applying patch files on top of a source tree. Still it's missing the initial step as far as I can tell, which is about the logic that will be receiving the data from Patchwork to get a pipeline running with it.

[gctucker]

I think we should be able to merge this one, just added some comments about a few minor things to tweak. It's not used in the code base yet but it makes sense to have it as a utility method for the rest, and the way kernel builds are done will need to be reworked anyway for the new pipeline so this will all get consolidated again in the near future.

[gctucker]

No I mean, I think we should actually remove these lines. Say, if you're doing this over your working kernel source tree and you don't specify command line arguments with your current user name and email then it will replace it. And then next time you make a commit in the kernel source tree it'll be with the [email protected] email.

So it should be left to the user to manage this outside of kci_build.

[yurinnick]

You mean it should be part of KernelCI config files or something? Sorry, I am not quite following what do you mean. Git won't allow to apply patches without name and email being set though.

[gctucker]

It should be part of the user's Git config, yes. Or we could maybe have a separate command to set the user name and email explicitly if some CI systems need to do that, as a handy wrapper.

Git won't allow to apply patches without name and email being set though.

Yes and that's fine. If there's no user name and email configured then git will fail and the issue will be on the user to solve it. Just like running any other invalid command (say, if kdir is not a Git repo etc.).

[pawiecz]

@yurinnick Please correct me if I'm wrong: this PR is a dependency to kernelci/kernelci-pipeline#295 which has been closed.

Can this one be closed as well or is it still intended to be used somewhere? If it is being repurposed, could you point me where it's used (I wasn't able to locate any)?

[yurinnick]

@pawiecz there was some back-n-forth on a best way to apply patches, I think it's safe to close for now and re-open if you'll need to get back to it.