Maveniverse Nisse

This is a near-trivial Maven 3 extension, that provides following services:

• extension and plugin: sources properties from different sources and makes them available in build
• extension only: redoes the CI Friendly Versions feature (not with Plugin)
• extension only: is able to "inline" properties, so there is no need to flatten or any other mumbo-jumbo, it "just works" (not with Plugin)

Implemented Sources

Currently there are 4 sources just to showcase things:

• file-source: it reads up a Java Properties File from disk
• jgit-source: it uses Eclipse JGit to get some git related data
• mvn-source: it provides major/minor/patch versions of currently used Maven
• os-source: heavily inspired by https://github.com/trustin/os-maven-plugin (and annoyed that user does not maintain it, so code is not reusable nor works with Maven4)

Look into ITs for examples.

Usage with Maven 3.9.x and 3.8.x

Nisse offers a Plugin and a Core Extension. With using Plugin only, features you can use is LIMITED to properties injection into Project properties (a la properties-maven-plugin from Mojohaus). To use Nisse Plugin, add it to your POM like this:

  <plugin>
    <groupId>eu.maveniverse.maven.nisse</groupId>
    <artifactId>plugin3</artifactId>
    <version>${version.nisse}</version>
    <executions>
        <execution>
            <id>inject-properties</id>
            <goals>
                <goal>inject-properties</goal>
            </goals>
            <phase>validate</phase>
        </execution>
    </executions>
  </plugin>

The Nisse Extension extension3 is more powerful, to use it add this to your .mvn/extensions.xml file:

<?xml version="1.0" encoding="UTF-8"?>
<extensions>
    <extension>
        <groupId>eu.maveniverse.maven.nisse</groupId>
        <artifactId>extension3</artifactId>
        <version>${version.nisse}</version>
    </extension>
</extensions>

And then you can inspect what is being added to user properties by running Toolbox dump:

$ mvn eu.maveniverse.maven.plugins:toolbox:dump -Dverbose -N

Look for "USER PROPERTIES" section. Nisse injected some properties for you as they were user properties. Moreover, you are free to use them as version (ie. <version>${nisse.jgit.commit}</version>) and look what happens. Oh, and just install/deploy as usual, no need for any mumbo-jumbo.

With extension present, the "CI friendly feature" of Maven is improved as:

• it allows ANY expression in version, as long it is defined (effective POM will not have expression left)
• there is no need to use flatten plugin to install/deploy, as version used expressions are inlined in POM.

Usage with Maven 4.0.x

Current stance is that Maven 4 will support similar features out of the box. Nisse does not work with Maven 4 currently, but things may change.