Branch snapshots

This is a sample on how to publish branch snapshots to the GitHub Maven registry:

A GitHub Actions workflow with a job publish-java-snapshot that publishes independent snapshots for each branch, in the form <version number>-<branch name>-SNAPSHOT.
Uses a reusable Action: https://github.com/javiertuya/branch-snapshots-action.
The project pom.xml that includes the necessary configuration to publish the snapshots to GitHub Packages and the releases to Maven Central

Detailed information on GitHub Packages can be found here: https://docs.github.com/en/packages/working-with-a-github-packages-registry/working-with-the-apache-maven-registry.

To consume (install) the snapshots from a local development environment, Jenkins or GitHub Actions, follow the below instructions.

Configure the pom.xml (common to all environments)

Declare the GitHub repository in the pom.xml (you can specify * instead of the repo name), example:

  <repositories>
    <repository>
      <id>github</id>
      <url>https://maven.pkg.github.com/javiertuya/branch-snapshots</url>
      <snapshots>
        <enabled>true</enabled>
      </snapshots>
    </repository>
  </repositories>

and follow the below instructions for each environment

Install from GitHub Actions

The workflow requires authentication with a token with scope read:packages. This can be achieved by specifying the environment variable GITHUB_TOKEN associated with the workflow repository:

      - name: Build and test
        run: mvn test -U
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

Install from a local development environment

Authentication must be included in a settings.xml file in your ~/.m2 folder. The id (github in the example) must match the id indicated in the pom.xml file. The GitHub token must have the read:packages scope:

<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0
                      http://maven.apache.org/xsd/settings-1.0.0.xsd">
  <servers>
    <server>
      <id>github</id>
      <username>USERNAME</username>
      <password>TOKEN</password>
    </server>
  </servers>
</settings>

Install from Jenkins

Autentication is similar to that of a local environment, but you can safely save the token in Jenkins:

Place the settings.xml file in the jenkins node (agent) ~/.m2 folder.
For security reasons, instead of use a plain text token, you should use an environment variable, for example, ${GITHUB_TOKEN}
Add a "secret text" credential to Jenkins with the token ant take note of the credential_id
Then, use the Jenkins Credentials Binding Plugin (https://www.jenkins.io/doc/pipeline/steps/credentials-binding/) in your pipeline to inject the secret:

    withCredentials([string(credentialsId: 'credential_id', variable: 'GITHUB_TOKEN')]) {
      sh 'mvn test -U'
    }