GitHub Actions - how to access GitHub Maven packages via GitHub actions

Steps:

• Add a Personal Access Token (PAT) to your GitHub Repository with permissions repo, workflow, read:packages
• Add that token as repository secret named GHA_MVN_PKGS_READ: Repository -> Settings -> Secrets
• Add repository settings to project’s pom.xml. For GitHub Enterprise (https://docs.github.com/en/enterprise-server@3.5/packages/working-with-a-github-packages-registry/working-with-the-apache-maven-registry), set the url to https://maven.HOSTNAME/OWNER/REPO or even https://maven.HOSTNAME/OWNER/*.

...
  <repository>
    <!-- IMPORTANT: id must be the same as in the workflow yml -->
    <id>github-maven-packages</id>
    <name>GitHub Maven Packages</name>
    <!-- NOTE: GH-Enterprise uses prefix https://maven.HOSTNAME/
        e.g., https://maven.github.myawesomeco.com/ 
     -->
    <url>https://maven.pkg.github.com/<my-username>/</url> 
  </repository>

• Setup the actions/setup-java@v2 - like the docs (https://github.com/actions/setup-java/blob/main/docs/advanced-usage.md#Publishing-using-Apache-Maven) say:

. . .
  - name: Set up JDK 11
    uses: actions/setup-java@v2
    with:
      java-version: '11'
      distribution: 'temurin'
      server-id: github-maven-package

  - name: Print settings xml
    run: |
      $LocalMavenM2Dir = "$env:USERPROFILE\.m2\"
      type $LocalMavenM2Dir\settings.xml

  - name: build and unit test
    run: mvn -B clean test    # pulls in the dependencies
    env:
      GITHUB_ACTOR: juliusgb  # can be github org or github username
      # prefer your own instead of secrets.GITHUB_TOKEN (easier to track and can access private repos)
      GITHUB_TOKEN: $

GitHub uses the env variables GITHUB_ACTOR and GITHUB_TOKEN as the default credentials when it generates the settings.xml.

To see what the generated settings.xml looks like is what the step Print settings xml does (on Windows). If you’re on Linux, adjust the 2 lines after run: |.