How to use Maven assembly plugin with multi module maven project

Question

I am new to maven and spent ~3 days in generating the zip file with assembly plugin refering to http://www.petrikainulainen.net/programming/tips-and-tricks/creating-a-runnab

Answer 1

The basic thing you should change is to create a separate module where you do the packaging which will look like this.

   +-- root (pom.xml)
        +--- mod-1 (pom.xml)
        +--- mod-2 (pom.xml)
        +--- mod-assembly (pom.xml)

The pom in the mod-assembly will look like this:

<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/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <parent>
    <groupId>org.test.parent</groupId>
    <artifactId>root</artifactId>
    <version>1.0.0-SNAPSHOT</version>
  </parent>

  <artifactId>dist</artifactId>
  <packaging>pom</packaging>

  <name>Packaging Test : Distribution</name>

  <dependencies>
    <dependency>
      <groupId>${project.groupId}</groupId>
      <artifactId>module-one</artifactId>
      <version>${project.version}</version>
    </dependency>
    <dependency>
      <groupId>${project.groupId}</groupId>
      <artifactId>module-two</artifactId>
      <version>${project.version}</version>
    </dependency>
  </dependencies>

  <build>
    <plugins>
      <plugin>
        <artifactId>maven-assembly-plugin</artifactId>
        <executions>
          <execution>
            <id>make-bundles</id>
            <goals>
              <goal>single</goal>
            </goals>
            <phase>package</phase>
            <configuration>
              <descriptors>
                <descriptor>proj1-assembly.xml</descriptor>
              </descriptors>
            </configuration>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>

</project>

That will solve the problem with running maven-assembly-plugin in every child and the problem with the dummy descriptor. Here you can find a real example of such structure.

Furthermore having the modules in one folder and the dependencies in an other folder you can use a assembly descriptor like this:

  <id>bin</id>
  <formats>
    <format>zip</format>
  </formats>
  <includeBaseDirectory>false</includeBaseDirectory>
  <dependencySets>
    <dependencySet>
          <useProjectArtifact>false</useProjectArtifact>
          <useTransitiveDependencies>true</useTransitiveDependencies>
          <outputDirectory>lib</outputDirectory>
          <unpack>false</unpack>
          <excludes>
            <exclude>${project.groupId}:*:*</exclude>
          </excludes>
      </dependencySet>
  </dependencySets>
  <moduleSets>
    <moduleSet>
      <useAllReactorProjects>true</useAllReactorProjects>
      <binaries>
        <outputDirectory>modules</outputDirectory>
        <unpack>false</unpack>
      </binaries>
    </moduleSet>
  </moduleSets>

Answer 2

I think the post How to Assemble Multi-Module Project with Maven might answer your question with an example.

My answers to your questions:

1) You should add the Assembly plugin in the parent pom within the build and pluginManagement tags to reuse it in the modules; the post mentioned above is a good example on how to do it. You can also take a look at 8.6 Best Practise chapter, topic 8.6.2, of the online book 'Maven: The Complete Reference'.

2) The exclusion tag might be tricky. Again, take a look at 8.5 Controlling the Contents of an Assembly chapter of the online book 'Maven: The Complete Reference'. For example, the subtopic 8.5.4, about dependencySets mentions how to fine tune dependency includes and excludes for dependencySets; again, the subtopic 8.5.5, now about moduleSets, shows how to use it in that context.