Capturing the Unique Maven SNAPSHOT build number - maven-2

Question

I am looking for a way to capture the unique SNAPSHOT build number that was generated during the 'mvn deploy' phase of the build. I would like to be able to pass this version (during a Hudson build) to another process used for deploying to an application server. The key here is being able to capture the exact Maven SNAPSHOT build number, such as:
foobar-0.4-20100707.060244-11.war
I have noticed that Hudson is capturing this information if you archive the maven build artifact, but it is not clear how I can expose this variable and pass it to another job (which is what I want to do). I can see this variable in the Hudson Home directory, like so:
/hudson/jobs/JOB_NAME/builds/24/org.ace.widgets$foobar/archive/org.ace.widgets/foobar/0.4-20100707.060244-11
Any Maven and/or Hudson experts out there that have any clue how to expose the SNAPSHOT build number? Hudson is doing it?

Answer 1

Check out my answer to this slightly different problem where I use GMaven to access the project metadata after deploy. What they have in common is that you have to access the unique build number. So you could adapt the script so that after it has read the project meta data (after deploy) it stores the unique version in the maven properties:
pom.properties['uniqueVersion'] = uniqueVersion
If the appserver-deploy-process is also a maven plugin, access this property, otherwise store it as a file using something like this:
new File(pom.build.directory, "uniqueVersion.txt").text = uniqueVersion
Now you can pick it up from target/uniqueVersion.txt using a shell script or so.

Answer 2

A little bit late, but I just noticed that you have exactly the same problem I was facing. I needed to be able to deploy arbitrary build artifacts produced on a Windows box on AIX machines. The deployment process needed to be run locally on the AIX boxes. So I defined slaves on the AIX boxes that download the build artifacts from the build job that run on the Windows box. The master is on the Windows box.
To put it in short. The build job archives the necessary artifacts and triggers the deployment job with its build URL as the parameter (it is actually a "run parameter", but string would work too). The deploy job uses wget to determine the artifact URL (it searches for a artifact ID that contains certain texts, e.g. the artifact name without the version), and downloads the artifact with wget again. wget saves it without version, so that all my deployment scripts can run on the unversioned name. You can use the first step also to find out about the artifact name as well.
wget uses the remote API (xml version). If you don't want to use wget, there is a command line tool that will do the connection for you.
You can test it by appending following strings to the run URL of the build job and use the resulting URL in your webbrowser.
#to find the path (URL) of the artifact
api/xml?xpath=*/artifact[contains(fileName,"MyApp")]/relativePath/text()
#to find the path (URL) of the artifact with more than 1 string to match
#the match must identify exactly one artifact, otherwise you will
#get an error message
api/xml?xpath=*/artifact[contains(fileName,"MyApp") and contains(fileName,".ear")]/relativePath/text()
#To download the artifact
#replace $relativePath with the actual output from one of the queries above
artifact/$relativePath

Answer 3

Based on Sean Patrick Floyds answer, even though this question is old, I'd like to share a full code example which writes the uniqueVersion into a maven property. Please keep in mind that Maven's internals are accessed using reflection, so this may easiliy breaks up in future maven versions. I tested it against Maven 3.2.5.
<build>
<plugins>
<plugin>
<groupId>org.codehaus.groovy.maven</groupId>
<artifactId>gmaven-plugin</artifactId>
<executions>
<execution>
<id>set-uniqueVersion-property</id>
<phase>deploy</phase>
<goals>
<goal>execute</goal>
</goals>
<configuration>
<source>
<![CDATA[
def uniqueVersion = null;
println "Grabbing uniqueVersion...";
project.artifact.metadataList.each{
if(it.class.simpleName=='ProjectArtifactMetadata'){
def afi = it.class.superclass.superclass.getDeclaredField('artifact');
afi.accessible = true;
uniqueVersion = it.artifact.version;
}
};
project.properties['uniqueVersion'] = uniqueVersion;
println("Unique Version grabbed: $uniqueVersion");
]]>
</source>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
If you want to use this property within other maven plugins, please make sure that their executions are made in the deploy phase after the set-uniqueVersion-property execution. If you prefer to write the unique version to a file, simply add
new File(pom.build.directory, "uniqueVersion.txt").text = uniqueVersion
as already stated by Sean Patrick.