GitLab Maven Repository

Introduced in GitLab Premium 11.3.

With the GitLab Maven Repository, every project can have its own space to store its Maven artifacts.

GitLab Maven Repository

Enabling Maven Repository

Note: This option is available only if your GitLab administrator has enabled Maven Repository.

In order to use the GitLab Maven Repository, you must enable the Repository. To enable (or disable) it:

  1. Navigate to your project's Settings > General > Permissions.
  2. Find the "Packages" feature and enable it.
  3. Click on Save changes for the changes to take effect.

You should then be able to see the Packages section on the left sidebar. Next, you must configure your project to authorize with the GitLab Maven repository.

Authenticating to the GitLab Maven Repository

If a project is private or you want to upload Maven artifacts to GitLab, credentials will need to be provided for authorization. Support is available for personal access tokens and CI job tokens.

Authenticating with a personal access token

To authenticate with a personal access token, add a corresponding section to your settings.xml file:

<settings>
  <servers>
    <server>
      <id>gitlab-maven</id>
      <configuration>
        <httpHeaders>
          <property>
            <name>Private-Token</name>
            <value>REPLACE_WITH_YOUR_PERSONAL_ACCESS_TOKEN</value>
          </property>
        </httpHeaders>
      </configuration>
    </server>
  </servers>
</settings>

You should now be able to upload Maven artifacts to your project.

Authenticating with a CI job token

If you're using Maven with GitLab CI/CD, a CI job token can be used instead of a personal access token.

To authenticate with a CI job token, add a corresponding section to your settings.xml file:

<settings>
  <servers>
    <server>
      <id>gitlab-maven</id>
      <configuration>
        <httpHeaders>
          <property>
            <name>Job-Token</name>
            <value>CI_JOB_TOKEN</value>
          </property>
        </httpHeaders>
      </configuration>
    </server>
  </servers>
</settings>

You can read more on how to create Maven packages using GitLab CI/CD.

Configuring your project to use the GitLab Maven repository URL

To download and upload packages from GitLab, you need a repository and distributionManagement section respectively in your pom.xml file:

<repositories>
  <repository>
    <id>gitlab-maven</id>
    <url>https://gitlab.com/api/v4/projects/PROJECT_ID/packages/maven</url>
  </repository>
</repositories>
<distributionManagement>
  <repository>
    <id>gitlab-maven</id>
    <url>https://gitlab.com/api/v4/projects/PROJECT_ID/packages/maven</url>
  </repository>
  <snapshotRepository>
    <id>gitlab-maven</id>
    <url>https://gitlab.com/api/v4/projects/PROJECT_ID/packages/maven</url>
  </snapshotRepository>
</distributionManagement>

The id must be the same with what you defined in settings.xml.

In both examples, replace PROJECT_ID with your project ID which can be found on the home page of your project.

If you have a self-hosted GitLab installation, replace gitlab.com with your domain name.

Uploading packages

Once you have set up the authorization and configuration, test to upload a Maven artifact from a project of yours:

mvn deploy

You can then navigate to your project's Packages page and see the uploaded artifacts or even delete them.

Creating Maven packages with GitLab CI/CD

Once you have your repository configured to use the GitLab Maven Repository, you can configure GitLab CI/CD to build new packages automatically. The example below shows how to create a new package each time the master branch is updated:

  1. Create a ci_settings.xml file that will serve as Maven's settings.xml file. Add the server section with the same id you defined in your pom.xml file. For example, in our case it's gitlab-maven:

    <settings xmlns="http://maven.apache.org/SETTINGS/1.1.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.1.0 http://maven.apache.org/xsd/settings-1.1.0.xsd">
      <servers>
        <server>
          <id>gitlab-maven</id>
          <configuration>
            <httpHeaders>
              <property>
                <name>Job-Token</name>
                <value>CI_JOB_TOKEN</value>
              </property>
            </httpHeaders>
          </configuration>
        </server>
      </servers>
    </settings>
    
  2. Make sure your pom.xml file includes the following:

    <repositories>
      <repository>
        <id>gitlab-maven</id>
        <url>https://gitlab.com/api/v4/projects/PROJECT_ID/packages/maven</url>
      </repository>
    </repositories>
    <distributionManagement>
      <repository>
        <id>gitlab-maven</id>
        <url>https://gitlab.com/api/v4/projects/PROJECT_ID/packages/maven</url>
      </repository>
      <snapshotRepository>
        <id>gitlab-maven</id>
        <url>https://gitlab.com/api/v4/projects/PROJECT_ID/packages/maven</url>
      </snapshotRepository>
    </distributionManagement>
    
    Tip: You can either leave GitLab CI/CD to replace your project ID value while the deploy job is running or hardcode your project's ID.
  3. Add a deploy job to your .gitlab-ci.yml file:

    deploy:
      image: maven:3.3.9-jdk-8
      script:
        - 'cp ci_settings.xml /root/.m2/settings.xml'
        - 'sed -i "s/CI_JOB_TOKEN/${CI_JOB_TOKEN}/g" /root/.m2/settings.xml'
        - 'sed -i "s/PROJECT_ID/${CI_PROJECT_ID}/g" pom.xml'
        - 'mvn deploy'
      only:
        - master
    
  4. Push those files to your repository.

The next time the deploy job runs, it will copy ci_settings.xml to the user's home location (in this case the user is root since it runs in a Docker container), and sed will replace the placeholder values with the contents of the actual environment variables.