[JENKINS-34846] Migrate to 2.9 plugin pom

[armfergom]

• [x] Upgrade to 2.9 parent pom
• [x] Bump baseline to 1.580.1
• [x] Fix Javadoc issues

@reviewbybees

[ghost]

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[armfergom]

Reopening to retrigger CI build. This time with-Dconcurrency=4 instead of -Dconcurrency=1C

[armfergom]

mvn clean install builds ok. CI job is configured to mark build as unstable if there are findbugs errors though. That's why this PR has failed checks.

Fixing findbugs errors were out of the scope of this PR, but if it needs to be done to get it merged I'll revisit it.

[ikedam]

The change looks good. (Of course, you need to fix findbug errors) But I don't like to upgrade the target Jenkins version unless it is actually necessary for features of the plugin.

I want to know more contexts of this request (that is, why you want this change). Do you plan to migrate all plugins to parent pom 2.x?

[armfergom]

@ikedam There is no parent pom since 1.646 onwards so the PCT will fail for Jenkins versions above that. Also, it is just an easy win and adds some benefits that you can see here.

I have bumped the baseline version because of incompatibilities with the jenkins test harness, but I can work around it if you prefer to keep the same baseline. Will also fix Findbugs issues.

And no, I am not planing to migrate all plugins, just a few :)

[armfergom]

@ikedam Addressed your comments. Given that you would like to keep 1.466 baseline, the jenkins test harness to use cannot be 2.6. It has to be 1.466 too. Also, sisu-guice is a banned dependency for newer versions of the core, but it is required for 1.466 baseline, so I cannot simply exclude it. For that reason, I've had to override the maven-enforcer-plugin configuration so that sisu-guice is not banned anymore (keeping the other declared banned dependencies in the core).

As for Findbugs errors, when keeping 1.466 baseline, no Findbugs errors are detected.

[ikedam]

Thanks a lot! Looks perfect to me.

And no, I am not planing to migrate all plugins, just a few :)

I hesitated to migrate to the new parent pom as I thouhgt I can't do that without migrating the target Jenkins version (Especially I misunderstood that I have to use jenkins-test-harness 2.x for the new parent pom). You showed me that plugins with older target Jenkins versions can migrate to the new parent pom.m, thanks!

Why don't we have all plugins migrate to the new parent pom? (e.g. announcing on jenkinsci-dev and ask developers to update their plugins)

[armfergom]

@ikedam The thing is, the new parent pom brings the jenkins-test-harness dependency with it. Specifically, version 2.9 of the parent pom brings jenkins-test-harness version 2.6. The problem was that newer versions of the jenkins-test-harness do not work well with older baselines. But fortunately, the new parent pom allows us to override the jenkins-test-harness version to use, so I just stuck with 1.466.

As for migrating (or asking to migrate) all plugins, I don't think it is critical at the moment, rather a nice to have. In any case, I think there is already a thread (here) where this is discussed.

[ikedam]

Oops, the link to google groups doesn't work. (it looks link to the search cache) Can I have the subject of the thread?

[armfergom]

The subject was "[PROPOSAL] New Parent POM for Jenkins Plugins"

[ikedam]

I got it. Thanks. I agree that was the announce. I'll start my other plugins to migrate to the new parent pom.

[andresrc]

:bee:

[kwhetstone]

:bee: Looks good