How to access maven dependecy from GitHub Package Registry (Beta)

Question

I uploaded a maven artefact to the GitHub Package Registry (Beta) and want to add it as maven dependency. I'm already in the Regestry-Beta and activated it for my sample HalloMaven project. Also the mvn deploy was succesful, so the artifact is public available here: https://github.com/TobseF/HelloMaven/packages
But how to include it as a maven dependency?

I tried to add it in a fresh sample project with this pom.xml:

<groupId>de.tfr.test</groupId>
<artifactId>maven-repo-test</artifactId>
<version>1.0-SNAPSHOT</version>

<repositories>
    <repository>
        <id>github</id>
        <name>GitHub TobseF Apache Maven Packages</name>
        <url>https://github.com/TobseF/HelloMaven/packages</url>
        <!-- also tried:
        <url>https://maven.pkg.github.com/HelloMaven/</url> -->
    </repository>
</repositories>


<dependencies>
    <dependency>
        <groupId>github.tobsef</groupId>
        <artifactId>hello-maven</artifactId>
        <version>1.2.1</version>
    </dependency>
</dependencies>

But the dependency cannot be resolved. It's strange that the artifactId is github.tobsef.hello-maven, which doesn't match the hello-maven specified in the pom. But I have no clue why the github.tobsef gets prepended and if the repository url is correct.

The official GitHub Configuring Apache Maven for use with GitHub Package Registry only shows how to push it with credentials. But my repo is public, authentication is not needed.

Setup for the HalloMaven example:

settings.xml

    <profiles>
        <profile>
            <id>github</id>
            <repositories>
                <repository>
                    <id>github</id>
                    <name>GitHub TobseF Apache Maven Packages</name>
                    <url>https://maven.pkg.github.com/TobseF</url>
                </repository>
            </repositories>
        </profile>
    </profiles>

    <servers>
        <server>
            <id>github</id>
            <username>${env.GITHUB_USERNAME}</username>
            <password>${env.GITHUB_TOKEN}</password>
        </server>
    </servers>

pom.xml

   <groupId>github.tobsef</groupId>
    <artifactId>hello-maven</artifactId>
    <version>1.2.1</version>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.1</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>
            <plugin>
                <artifactId>maven-deploy-plugin</artifactId>
                <version>2.8.1</version>
            </plugin>
        </plugins>
    </build>

    <properties>
        <github.global.server>github</github.global.server>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>11</java.version>
        <maven.compiler.source>11</maven.compiler.source>
        <maven.compiler.target>11</maven.compiler.target>
    </properties>

    <distributionManagement>
        <repository>
            <id>github</id>
            <name>GitHub TobseF Apache Maven Packages</name>
            <url>https://maven.pkg.github.com/TobseF/HelloMaven</url>
        </repository>
    </distributionManagement>

deploy.yml

name: Maven Deploy

on:
  push:
    branches:
      - master

jobs:
  build:

    runs-on: ubuntu-latest

    steps:
      - uses: actions/checkout@v1
      - name: Set up JDK 11
        uses: actions/setup-java@v1
        with:
          java-version: 11
      - name: Maven build
        run: mvn --file pom.xml package

  deploy:

    runs-on: ubuntu-latest

    steps:
    - uses: actions/checkout@v1
    - name: Set up JDK 11
      uses: actions/setup-java@v1
      with:
        java-version: 11
    - name: Deploy to Github Package Registry
      env:
        GITHUB_USERNAME: ${{ secrets.GITHUB_USERNAME }}
        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
      run: mvn --settings settings.xml --file pom.xml deploy

The result is a Could not find artifact github.tobsef:hello-maven:pom:1.2.1 in github (https://github.com/TobseF/HelloMaven/packages).

Any Idea how to setup the deployment to deploy the correct artifact and how to add it as dependency?

Answer 1

OK ✅, I found out how to configure it the right way.

You can see a sample project with the working GitHub Actions CI and the GitHub Package Registry here:
👉 HelloMaven
To see how the dependency can be included check the:
👉 GitHub-plugin-registry-example Template

The trick was to add an authentification to the GitHub API in the global maven settings.xml.

<servers>
    <server>
        <id>github</id>
        <username>YOUR_USERNAME</username>
        <password>YOUR_AUTH_TOKEN</password>
    </server>
</servers>

Replace the YOUR_USERNAME with your GitHub login name.
Replace the YOUR_AUTH_TOKEN with a generated GitHub personal access token:
GitHub > Settings > Developer Settings > Personal access tokens > Generate new token:
The token needs at least the read:packages scope. Otherwise you will get a Not authorized exception.

It wasn't clear that this auth is also needed to read a package. Especially because the jar is available without any login on the package page: https://github.com/TobseF/HelloMaven/packages

So it's a little bit nasty because we have to add the <server><id>github</id>... and hope others will also provide the the repository with the github id. Otherwise we have to add a server config for every github dependency.

Keep in mind that every GitHub repo is its own maven repo. So there is no global registry like the maven central. Every dependency has to provide its own repository link declaration.

But in combination with the GitHub Actions CI, it's a very nice alternative without any third party plugins.