Question

I have a custom plugin that I run on all our projects as part of the release:perform goal.

We are just starting to use multi-module builds, and I notice that my plugin only runs at the top module. What do I have to do to my plugin to make it run on all the modules individually at the end of the release? Do I have to iterate through them in the plugin code itself? If so, is there an example of doing that, because from what I see, MavenProject.getModules() just returns a list of String names of those modules, and I can’t see how to get info for those modules (my plugin needs the groupId:artifactId:version of each, and in this case, the modules do not always have the same version).

I’ve tried with and without @aggregator, but that doesn’t change anything with respect to my problem.

I’m assuming this is the same case as running the plugin directly (not tied to a phase) from CLI, which also only runs on the top-level of the project, and reports SKIPPED for all the sub-modules.

I am using Maven 3.0.3.

Answer 1

I had the same problem with my Maven plugin. It was only being invoked once (generally for the first module in the reactor), and I eventually traced it to the fact that my plugin had the Maven annotation “@requiresProject false”. It seems that the Maven Reactor only invokes such plugins once. Once I switched to “@requiresProject true”, my mojo was invoked once for each module. I wasn’t hooking into release:perform, so YMMV.

As for accessing all the modules, instead of using MavenProject.getModules() which gives their names, you could inject their MavenProject objects like this:

   /**
    * The projects in the reactor.
    *
    * @parameter expression="${reactorProjects}"
    * @readonly
    */
   private List<MavenProject> reactorProjects;

Watch out for @aggregator when binding to lifecycle phases. “When bound to a lifecycle, an aggregator mojo can have some nasty side-effects. It can force the execution of the … lifecycle phase to execute ahead of time, and can result in builds which end up executing the … phase twice.” ref

How do you force a maven MOJO to be executed only once at the end of a build? has some alternatives to @aggregator.