Support maven-p2-site generation as part of regular tycho build

[laeubi]

A recent discussion has shown that there are demands to have pure p2-sites as part of the tycho build as well.

The proposal is to add a new packaging type p2-maven-repository that has the tycho-p2-repository:assemble-maven-repository bind to the package of its life-cycle and automatically depend on al bundle-project of the reactor.

This would make the usage of the site mojo inside a regular tycho build more convenient.

[mickaelistria]

I don't really get what such a new packaging type would make noticeable simpler? Can you please provide some examples of before/after?

[laeubi]

The main goal would be to have a simple pom.xml in the form of

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<groupId>tycho.example</groupId>
	<artifactId>p2-site</artifactId>
	<version>1.0.0-SNAPSHOT</version>
	<packaging>maven-repository</packaging>
</project>

that simply builds a maven-repository site based on all reactor projects. The problem is that currently (tom ake it right) one has to declare all projects as dependencies, or use the reactor strategy and find a way to build the site project as the last item inside a tycho build.

My idea would be that the TychoMavenLifeCycleParticipant could handle such packaging special and simply add all bundle-projects as dependencies.

[mickaelistria]

What about transitive deps or extra deps? I'm afraid that in practice, for a p2 repo to be useful, one would always need some tricks to add some extra deps, and that can already be covered by category.xml. So overall, I think it could be a regular eclipse-repository with an extra customatization of the https://www.eclipse.org/tycho/sitedocs/tycho-p2/tycho-p2-repository-plugin/assemble-repository-mojo.html to "includeAllReactorArtifacts" (and which would be able to run with or without a category.xml).

[laeubi]

Nope one doesn't want to assemble a repository with extra dependencies just make the current reactor units available as p2 consumable maven artifact site.
category.xml does not help here as one has then list everything there to get the desired result.

[mickaelistria]

Can you please remind what is it you call " p2 consumable maven artifact site" ?