[CONTINUUM-1657] Split configuration of pom location, when adding new M2 projects, into two parts; optionally specify a workspace into which a (modular-)project should be checked-out.

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 1.1
• Component/s: Core system, SCM, Web - Configuration
• Labels: backlog-to-cleanup
• Environment: Windows XP Prof; Tomcat 5.5.x; Continuum 1.1-SNAPSHOT
• Assignee: Unassigned
• Reporter: Darren Bishop
• Created: 13/Feb/08 05:20
• Updated: 20/Nov/12 01:09

Description

Split configuration of the pom.xml location, when adding new M2 projects. Currently, projects are checked-out from SCM at the directory containing the pom.xml, which is not always what one wants.

Also, optionally specify a workspace into which a (modular-)project should be checked-out. Currently, projects are checked-out from SCM into a directory named by that particular build number.

The following pathology exists when trying to implement CI with flat-modular projects:

Project Layout (in SCM/SVN)

modproj/
    |-- trunk/ (part of subversion versioning tree)
        |-- module-1/
            |-- pom.xml
        |-- module-2/
            |-- pom.xml
        |-- module-3/
            |-- pom.xml
        |-- reactor/
            |-- pom.xml (this is the parent pom i.e. it contains the list of modules; see next)

And the reactor in ../trunk/reactor/pom.xml

The 'Reactor'

 
<modules>
    <module>../module-1</module>
    <module>../module-2</module>
    <module>../module-3</module>
</modules>

Let's assume the Continuum working directory is $CONTEXT_WEB_INF/builds.
Let's also assume because we are adding a new project that the build number will be 1.
To add a M2 modular/reactor-project, one specifies the SCM URL to the reator pom.xml e.g. in the case above, something like scm:svn:http:/svn/modproj/trunk/reactor/pom.xml.
When the first build is triggered, it checks out http:/svn/modproj/trunk/reactor into $CONTEXT_WEB_INF/builds/1.
Maven will try to resolve the location of the modules, traversing up a directory into builds and then trying to traverse down into, let's say, module-1 - but a directory of that name does not exist.. Furthermore, {{module-

Unknown macro: {1,2,3}

}} have not even been checked-out.
And so the build fails.

What I propose is to add an additional configuration step (hence improvement, not new feature) to the new M2 project page,:

• Split the POM Url field into two:
  • The first field specifies the project root i.e. not the project's pom.xml. For the scenario above one would enter scm:svn:http:/svn/modproj/trunk
  • The new second field specifies the location of the project's pom.xml relative to the root of the check-out. For example reactor/pom.xml
    • A sensible default would be just pom.xml i.e. making the assumption that the file is in the root of the check-out.

With this approach, Continuum has atleast the same information as the current approach (for backwards compatibility) but also has the intention of the developer/administrator w.r.t. the layout of the project.

Optionally, a third field can be added that lets you specify a workspace for your project's individual builds and that Continuum checks out into. For the scenario above, if this workspace was modproj (...hint hint), then Continuum would check-out into 1/modproj/ all the modules including reactor.

This has better fidelity to what a developer does on their workstation, especially us Eclipse users.

Issue Links

• relates to: CONTINUUM-1569 Release of a flat structure multi-module project doesn't work
• supercedes: CONTINUUM-1163 Flat SCM Structure + Continuum = broken module-links on site