Branch and PR builds on ci.eclipse.org/omr

[charliegracie]

The Eclipse OMR project recently obtained some Linux PPC LE and Linux 390 machines to perform automated testing for PR and pushes to branches. The Eclipse foundation enabled a Jenkins CI server for us which we will be using to perform testing on the 2 platforms mentioned above. To help launch builds and set GitHub status for a commit we will be using a bot account named genie-omr.

When a PR is opened the new CI testing will not automatically kick off builds. To start the PR builds a committer has to put a comment in the PR with the following text genie-omr build [all,zlinux,plinux,zos,aix]. When this comment is added one of each of the PR builds will be started. Currently committers and whitelisted contributors can launch all of the PR builds with this command as there is no mechanism to allow a selection. In the future they may be able to select certain platforms based on the code that has changed. These builds will set a GitHub status similar to the Travis.vi and AppVeyor builds already being used by the Eclipse OMR project. You can check out the status of the commit in #1683 to see an example of how the Eclipse OMR CI updates the PR commit status. The Jenkins plugin being used for this fully supports the [skip ci] tag but since we are only launching builds via a request it should not matter right now.

When a PR is merged into a branch (currently there is only master) or a commit is pushed directly (this is not currently allowed in this project) builds will be kicked off for each of the branch builds on the projects Jenkins CI. These jobs will also update the GitHub status for the commit they test. You can see an example of what the status check looks like for these builds here if you click on the status for any recent merge commit (starting with SHA 0366145). Currently this build does not support and sort of [skip ci] tag but it is something we can incorporate over time.

[charliegracie]

Possible improvements/modifications:

• [x] I think we may want to change the text used to launch the PR builds. Currently it is genie-omr build but I think we should switch it to @genie-omr build. While setting this up and testing mistakes we made with typing the text and if we actually use the @ symbol we can tab/auto complete most of the text and it will cause less errors :). Does anyone have any thoughts? This should work now.
• [x] Add support to the PR build to build a list of platforms instead of building all platforms. I think this is something that could be set up relatively easily. The issue I see with this is getting the platform names right. The upside to being able to specify a list of platforms is that if you get one wrong you can just add another comment to build that one platform.
• [ x] ~Modify the skip build tag to accept both [skip ci] and [ci skip] as it is just a "simple" regex.~ This should not be required since builds are launched manually.
• [ ] Document how contributors can get added to the whitelist for launching builds.
• [ ] Support [skip ci] and [ci skip] tags for the branch builds
• [x] Add badges for the Eclipse OMR CI builds to the README.md

[mgaudet]

Currently only committers can launch builds I believe; Is there a middle ground state we expect where non-committers may gain the ability to launch builds, but not become a committer?

[charliegracie]

There is a mechanism for adding users and github organizations to a whitelist which I believe allows them to launch builds in their own PRs (maybe any PR but it I haven't tested yet). My opinion is that we grant users/organizations this ability very quickly. If a contributor is known to the project I say we should allow them to launch builds. My 2 cents but we will need consensus from the leads and committers.

[charliegracie]

@mgaudet I added you to the whitelist to help test out the support :). Do you want to try launching the CI build in #1704?

[mgaudet]

Looks to have worked 👍

[charliegracie]

Updated the text to reflect this :) Thanks

[charliegracie]

@mstoodle, @0xdaryl, @youngar, @vijaysun-omr and @jduimovich any thoughts on on the current process and the suggested improvements/modifications?

[mgaudet]

• IIRC the travis skip tag is [ci skip] -- your docs say the Jenkins one is [skip-ci]; can we harmonize these?
• I think we should document the process by which you get the ability to launch builds, but agree, the bar should be low. Small number of contributions. Unfortunately, we should also say that the ability can be revoked at any time for any reason.

[charliegracie]

• By default the Jenkins GHPRB plugin uses [skip-ci]. I could switch it but Travis.ci actually accepts both versions. I can likely update the Jenkins CI to accept both. I will add it to the TODOs.
• That is a good idea. Adding to the TODOs

[mgaudet]

If a downstream project is available in the open, do you foresee implementing the ability to request a build that combines a PR and downstream project?

genie build dependent rubyomr

or somesuch?

[charliegracie]

hmmm it appears sometimes the command only kicks off one of the builds (it seems to miss the PPC LE one if it misses a build). We should keep an eye on it but I think it means we should implement the ability to kick off a single platform sooner rather than later. EDIT: I have added the ability to launch just a single platform and updated the original text