[m2] how to report from a specific plugin goal?

[David Sag <ds...@epo.org>]

I am writing a QALab plugin for Maven2.

Its goals are meant to be run via continuous integration machine rather 
than by a specific developer.

To function it needs the XML reports from one or more of the following:

Checkstyle, PMD, Simian, FindBugs.

For now I am just focusing on merging the Checkstyle report to get it 
working, and will enhance it later.

I currently generate my checkstyle report as part of the 'site' goal.

I figured, based on some discussion on the users list, that adding my 
qalab plugin to my reports too would work but I can't for the life of me 
see how I specify which goal aught to be run.

How do I tell the pom.xml file which goal to trigger within my plugin to 
add its output to the site.

Why doesn't the checkstyle plugin need a specific goal to work?

Kind regards,
Dave Sag