Maven is a great tool, but it has one constraint that makes it inapplicable in many cases.
It can checkout the whole project (pom.xml and sources) from a single place in SCM storage using a single tag.
It's quite suitable in open-source projects, where new versions of projects don't appear too often.
But in our company we have a lot of components, each of which is stored in its own place in SCM and tagged with its own tag. To make using Maven possible, we need to create either BASH or ANT script which would check out all required projects from SCM.
This is the concern:
why do I need Maven if i still need ANT for running it?If only Maven could do it by itself...
After thinking a while, we have created a solution.
As known, Maven SCM plugin has several SCM providers: CVS, Subversion, ClearCase etc.
Idea is to create one more provider, Proxy SCM. Its main goal is to checkout different modules from different places calling other SCM providers.
We need to extend pom.xml with 2 attributes:
Given pom.xml of form:
<module path="robots/terminator/ui" tag="terminator_ui_v1-2">terminator_ui</module>
<module scmProvider="svn" scmHost="http://svn.apache.org/repos/asf/commons/proper/launcher" path="trunk">commons_launcher</module>
The proxy-scm provider checks out all the 3 projects into 3 subfolders in current folder, resulting in the following content:
The code of proxy-scm provider is quite simple: it just needs to parse file "pom.xml" and call appropriate SCM provider for every module.
I would like to commit this code into the next Maven SCM version (1.1). But it seems those guys don't respond to JRA issues neither commit patches into new version :(