Maven multi-module project with license plugin

Question

I have a multi-module project in which I'm trying to set up the license plugin to manage all the licenses. Here's the project setup:

─── transfuse-project
    ├── examples
    │   ├── helloAndroid
    │   │   ├── pom.xml
    │   │   ├── ...
    │   ├── integrationTest
    │   │   ├── pom.xml
    │   │   ├── ...
    │   ├── pom.xml
    │   └── ...
    ├── transfuse
    │   ├── pom.xml
    │   ├── ...
    ├── transfuse-api
    │   ├── pom.xml
    │   ├── ...
    ├── NOTICE
    └── pom.xml

Each pom.xml inherits from the transfuse-project pom.xml. In the project pom.xml I have set up the license plugin to apply the NOTICE to the relevant files:

        <plugin>
            <groupId>com.mycila.maven-license-plugin</groupId>
            <artifactId>maven-license-plugin</artifactId>
            <version>1.9.0</version>
            <configuration>
                <header>NOTICE</header>
                <includes>
                    <include>**/*.java</include>
                    <include>**/*.xml</include>
                </includes>
                <excludes>
                    <exclude>**/.*/**</exclude>
                    <exclude>target/**</exclude>
                    <exclude>**/AndroidManifest.xml</exclude>
                </excludes>
                <properties>
                    <year>2013</year>
                    <name>John Ericksen</name>
                </properties>
                <useDefaultExcludes>true</useDefaultExcludes>
                <strictCheck>true</strictCheck>
            </configuration>
            <executions>
                <execution>
                    <id>check-headers</id>
                    <phase>verify</phase>
                    <goals>
                        <goal>check</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>

This configuration works if I build directly off of the root (transfuse-project). The problem arises when I build the integrationTest example or api directly. Maven cannot find the NOTICE file I provided in the project root:

[ERROR] Failed to execute goal com.mycila.maven-license-plugin:maven-license-plugin:1.9.0:check (check-headers) on project transfuse-api: Some files do not have the expected license header -> [Help 1]

And what's worse, it finds another dependency's NOTICE file. If I run mvn license:format in a sub-module it replaces all of the module's headers with the dependency's NOTICE file.

I believe I can add a NOTICE file within each sub-module to fix this problem and configure each sub-module pom with its own license plugin, but I would like to avoid that duplication if possible. Is there some configuration or setup that will work with my project setup?

Solution 1

Try to use an absolute path by using

<header>${basedir}/NOTICE</header>

If this doesn't work, try to set a property to and in the parent module's basedir and use it:

<header>${main.basedir}/NOTICE</header>

A third option is setting a property at runtime:

mvn clean install -Dmain.basedir=path/to/main/basedir

Edit:

Ok, a whole other option is to execute the maven-dependency-plugin before your license plugin. But you have to make sure the parent attaches the NOTICE (with maven-assembly-plugin plugin)

<plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-dependency-plugin</artifactId>
         <version>2.6</version>
         <executions>
           <execution>
             <id>unpack-parent</id>
             <phase>verify</phase>
             <goals>
               <goal>unpack</goal>
             </goals>
             <configuration>
               <artifactItems>
                 <artifactItem>
                   <groupId>parent</groupId>
                   <artifactId>parent</artifactId>
                   <version>parent</version>
                   <type>pom</type>
                   <overWrite>false</overWrite>
                   <outputDirectory>${project.build.directory}/license</outputDirectory>
                   <includes>NOTICE</includes>
                 </artifactItem>
               </artifactItems>
             </configuration>
           </execution>
         </executions>
       </plugin>

The header changes then in:

<header>${project.build.directory}/license/NOTICE</header>

Edit2:

I came across the find-maven-plugin. I think this could work:

<plugin>
    <groupId>com.github.goldin</groupId>
    <artifactId>find-maven-plugin</artifactId>
    <version>0.2.5</version>
    <executions>
        <execution>
            <id>find-notice-file</id>
            <goals>
                <goal>find</goal>
            </goals>
            <phase>validate</phase>
            <configuration>
                <propertyName>notice.file</propertyName>
                <file>NOTICE</file>
            </configuration>
        </execution>
    </executions>
</plugin>

Solution 2

There's actually a much easier way to do this. Just set the aggregate tag to true in the configuration. Here's the full maven-license-plugin definition:

<plugin>
    <groupId>com.mycila.maven-license-plugin</groupId>
    <artifactId>maven-license-plugin</artifactId>
    <version>1.10.b1</version>
    <configuration>
        <header>etc/header.txt</header>
        <aggregate>true</aggregate>
        <includes>
            <include>**/*.java</include>
        </includes>
    </configuration>
</plugin>

You then just need to have a file called header.txt in etc/header.txt in the parent root directory.

Comments

[John Ericksen]

ah, I tried that as well. Building from the root works, but building any of the sub-modules fails.

[John Ericksen]

Spoke too soon. This: ${project.parent.parent.basedir} does not seem to reference the grand-parent when built from the root. Ideas?

[John Ericksen]

would I add the dependency plugin to the root or each sub-module?

[asgoth]

In the root, but the execution should be in the child poms

[John Ericksen]

Ugh, ran into a bug in Maven with this solution: "[ERROR] Failed to execute goal org.apache.maven.plugins:maven-dependency-plugin:2.6:unpack (unpack-parent) on project transfuse-project: Unknown archiver type: No such archiver: 'xml'."

[John Ericksen]

I wonder, could I host the header online and reference it via url? Seems like a huge workaround, bit may solve my relative path issues.

[asgoth]

I found a plugin which searches a file in a parent path: evgeny-goldin.com/wiki/Find-maven-plugin. I've added it to the answer

[John Ericksen]

Edit2 works. I like the fact that it is only defined in the parent pom. Thanks again for your diligence, check mark well earned.

[abhiyenta]

This works when building the parent, but not when you build an individual module by itself.