How to use a Maven project to create a content package for CQ (or more specifically Sling)

This articles describes how to get hold of an example Maven project for creating a content package; how to use it to install a content package; and, a little bit of explanation of the POM provided.
Here are some important summary items.
Use the Maven archetype facility to download the sample.
The “packaging” directive must be set to “bundle”.
Use <Sling-Initial-Content> to define the content nodes to be installed.
See: sling.apache.org/site/content-loading-jcrcontentloader.html

Downloading the sample Maven project
$ mvn archetype:generate
...
301: remote -> org.apache.sling:sling-bundle-archetype (-)
302: remote -> org.apache.sling:sling-initial-content-archetype (Maven archetype for initial content)
303: remote -> org.apache.sling:sling-jcrinstall-bundle-archetype (-)
304: remote -> org.apache.sling:sling-launchpad-standalone-archetype (-)
305: remote -> org.apache.sling:sling-launchpad-webapp-archetype (-)
306: remote -> org.apache.sling:sling-servlet-archetype (Maven archetype for Sling Servlets)
….

Choose a number or apply filter (format: [groupId:]artifactId, case sensitive contains): 225: 302
Downloading: http://repo1.maven.org/maven2/org/apache/sling/sling-initial-content-archetype/1.0.0/sling-initial-content-archetype-1.0.0.jar
Downloaded: http://repo1.maven.org/maven2/org/apache/sling/sling-initial-content-archetype/1.0.0/sling-initial-content-archetype-1.0.0.jar (10 KB at 104.4 KB/sec)
Downloading: http://repo1.maven.org/maven2/org/apache/sling/sling-initial-content-archetype/1.0.0/sling-initial-content-archetype-1.0.0.pom
Downloaded: http://repo1.maven.org/maven2/org/apache/sling/sling-initial-content-archetype/1.0.0/sling-initial-content-archetype-1.0.0.pom (4 KB at 7.4 KB/sec)
Define value for property 'groupId': : com.mkalugin.cq5
Define value for property 'artifactId': : test-wibble
Define value for property 'version': 1.0-SNAPSHOT: :
Define value for property 'package': com.mkalugin.cq5: :
Confirm properties configuration:
groupId: com.mkalugin.cq5
artifactId: test-wibble
version: 1.0-SNAPSHOT
package: com.mkalugin.cq5
Y: :
[INFO] ----------------------------------------------------------------------------
[INFO] Using following parameters for creating project from Archetype: sling-initial-content-archetype:1.0.0
[INFO] ----------------------------------------------------------------------------
[INFO] Parameter: groupId, Value: com.mkalugin.cq5
[INFO] Parameter: artifactId, Value: test-wibble
[INFO] Parameter: version, Value: 1.0-SNAPSHOT
[INFO] Parameter: package, Value: com.mkalugin.cq5
[INFO] Parameter: packageInPathFormat, Value: com/mkalugin/cq5
[INFO] Parameter: package, Value: com.mkalugin.cq5
[INFO] Parameter: version, Value: 1.0-SNAPSHOT
[INFO] Parameter: groupId, Value: com.mkalugin.cq5
[INFO] Parameter: artifactId, Value: test-wibble
[INFO] project created from Archetype in dir: /cq/mkalugin-cq/projectX/proj-cq5-core/tmp/test-wibble
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 19.944s
[INFO] Finished at: Tue Oct 30 14:56:39 GMT 2012
[INFO] Final Memory: 7M/81M
[INFO] ------------------------------------------------------------------------
$ ls
test-wibble/

$ cd test-wibble
$ mvn -PautoInstallBundle install
…
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building test-wibble 1.0-SNAPSHOT
[INFO] ------------------------------------------------------------------------
…
[INFO] Installing Bundle com.mkalugin.cq5.test-wibble(/cq/mkalugin-cq/projectX/proj-cq5-core/tmp/test-wibble/target/test-wibble-1.0-SNAPSHOT.jar) to http://localhost:4502/system/console via POST
[INFO] Bundle installed
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
…

Anatomy of the POM
The above section showed how to get the example maven project for a CQ (more specifically a Sling) content package.
Now follows an analysis of the produced POM.

Standard first 3 lines :-
<?xml version="1.0" encoding="ISO-8859-1"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>

Now, our project specific information (NB, this appears in Felix bundles).

<groupId>com.mkalugin.cq5</groupId>
<artifactId>test-wibble</artifactId>
NB, Packaging is specified as "bunlde", this will be an OSGi bundle (not a CRX package).

<packaging>bundle</packaging>
<version>1.0-SNAPSHOT</version>
<name>test-wibble</name>
<description>com.mkalugin.cq5 - test-wibble</description>
Now comes the maven-bundle-plugin definition - this does the work of creating an OSGi Sling bundle with instructions of how to install (or uninstall if you wish) the content nodes.

<build>
    <plugins>        <plugin>            <groupId>org.apache.felix</groupId>            <artifactId>maven-bundle-plugin</artifactId>            <extensions>true</extensions>            <version>2.3.7</version>
Now comes the details of the content nodes and what we want to do with them.
            <configuration>            <instructions>            <Sling-Nodetypes> SLING-INF/nodetypes/nodetypes.cnd            </Sling-Nodetypes>            <Sling-Initial-Content> SLING-                                                                      INF/scripts;overwrite:=true;uninstall:=true;path:=/apps/my/node,            SLING-INF/content;overwrite:=true;uninstall:=true;path:=/content            </Sling-Initial-Content>            </instructions>            </configuration>        </plugin>    </plugins>
</build>
An autoInstallBundle profile is given by default showing how the produced bundle can be loaded & installed in to Felix.
This is documented at : http://sling.apache.org/site/content-loading-jcrcontentloader.html

</project>
    <profiles>        <profile>
            <id>autoInstallBundle</id>                <build>                     <plugins>                         <plugin>                             <groupId>org.apache.sling</groupId>                             <artifactId>maven-sling-plugin</artifactId>                             <version>2.1.0</version>                             <executions>                                 <execution>                                     <id>install-bundle</id>                                     <goals>
                                         <goal>install</goal>
                                     </goals>
                                     <configuration>                                      <slingUrl>http://localhost:4502/system/console</slingUrl>
                                           <user>admin</user>
                                           <password>admin</password>
                                     </configuration>
                                 </execution>
                             </executions>
                         </plugin>
                     </plugins>
                </build>
         </profile>
     </profiles>
</project>

Reference: http://sling.apache.org/site/content-loading-jcrcontentloader.html