Publish to the GitLab Package Registry
Publish a package
Install a package
Helpful hints
Troubleshooting
- Review network trace logs
- Verify your Maven settings

Maven packages in the Package Registry

Publish Maven artifacts in your project’s Package Registry. Then, install the packages whenever you need to use them as a dependency.

For documentation of the specific API endpoints that the Maven package manager client uses, see the Maven API documentation.

Supported clients:

mvn. Learn how to build a Maven package.
gradle. Learn how to build a Gradle package.
sbt.
- sbt can only be used to pull dependencies. See this issue 408479 for more details.

Publish to the GitLab Package Registry

Authenticate to the Package Registry

You need an token to publish a package. There are different tokens available depending on what you’re trying to achieve. For more information, review the guidance on tokens.

Create a token and save it to use later in the process.

Do not use authentication methods other than the methods documented here. Undocumented authentication methods might be removed in the future.

Edit the client configuration

You must add the authentication details to the configuration file for your client.

mvn

Token type	Name must be	Token
Personal access token	`Private-Token`	Paste token as-is, or define an environment variable to hold the token
Deploy token	`Deploy-Token`	Paste token as-is, or define an environment variable to hold the token
CI Job token	`Job-Token`	`${CI_JOB_TOKEN}`

The <name> field must be named to match the token you chose.

Add the following section to your settings.xml file.

<settings>
  <servers>
    <server>
      <id>gitlab-maven</id>
      <configuration>
        <httpHeaders>
          <property>
            <name>REPLACE_WITH_NAME</name>
            <value>REPLACE_WITH_TOKEN</value>
          </property>
        </httpHeaders>
      </configuration>
    </server>
  </servers>
</settings>

gradle

Token type	Name must be	Token
Personal access token	`Private-Token`	Paste token as-is, or define an environment variable to hold the token
Deploy token	`Deploy-Token`	Paste token as-is, or define an environment variable to hold the token
CI Job token	`Job-Token`	`System.getenv("CI_JOB_TOKEN")`

The <name> field must be named to match the token you chose.

In your GRADLE_USER_HOME directory, create a file gradle.properties with the following content:

gitLabPrivateToken=REPLACE_WITH_YOUR_TOKEN

Add a repositories section to your build.gradle file:

In Groovy DSL:

repositories {
    maven {
        url "https://gitlab.example.com/api/v4/groups/<group>/-/packages/maven"
        name "GitLab"
        credentials(HttpHeaderCredentials) {
            name = 'REPLACE_WITH_NAME'
            value = gitLabPrivateToken
        }
        authentication {
            header(HttpHeaderAuthentication)
        }
    }
}

In Kotlin DSL:

repositories {
    maven {
        url = uri("https://gitlab.example.com/api/v4/groups/<group>/-/packages/maven")
        name = "GitLab"
        credentials(HttpHeaderCredentials::class) {
            name = "REPLACE_WITH_NAME"
            value = findProperty("gitLabPrivateToken") as String?
        }
        authentication {
            create("header", HttpHeaderAuthentication::class)
        }
    }
}

sbt

Token type	Name must be	Token
Personal access token	The username of the user	Paste token as-is, or define an environment variable to hold the token
Deploy token	The username of deploy token	Paste token as-is, or define an environment variable to hold the token
CI Job token	`gitlab-ci-token`	`sys.env.get("CI_JOB_TOKEN").get`

Authentication for SBT is based on basic HTTP Authentication. You must to provide a name and a password.

The name field must be named to match the token you chose.

To install a package from the Maven GitLab Package Registry by using sbt, you must configure a Maven resolver. If you’re accessing a private or an internal project or group, you need to set up credentials. After configuring the resolver and authentication, you can install a package from a project, group, or namespace.

In your build.sbt, add the following lines:

resolvers += ("gitlab" at "<endpoint url>")

credentials += Credentials("GitLab Packages Registry", "<host>", "<name>", "<token>")

In this example:

<endpoint url> is the endpoint URL. Example: https://gitlab.example.com/api/v4/projects/<project_id>/packages/maven.
<host> is the host present in the <endpoint url> without the protocol scheme or the port. Example: gitlab.example.com.
<name> and <token> are explained in the table above.

Naming convention

You can use one of three endpoints to install a Maven package. You must publish a package to a project, but the endpoint you choose determines the settings you add to your pom.xml file for publishing.

The three endpoints are:

Project-level: Use when you have a few Maven packages and they are not in the same GitLab group.
Group-level: Use when you want to install packages from many different projects in the same GitLab group. GitLab does not guarantee the uniqueness of package names within the group. You can have two projects with the same package name and package version. As a result, GitLab serves whichever one is more recent.
Instance-level: Use when you have many packages in different GitLab groups or in their own namespace.

For the instance-level endpoint, ensure the relevant section of your pom.xml in Maven looks like this:

  <groupId>group-slug.subgroup-slug</groupId>
  <artifactId>project-slug</artifactId>

Only packages that have the same path as the project are exposed by the instance-level endpoint.

Project	Package	Instance-level endpoint available
`foo/bar`	`foo/bar/1.0-SNAPSHOT`	Yes
`gitlab-org/gitlab`	`foo/bar/1.0-SNAPSHOT`	No
`gitlab-org/gitlab`	`gitlab-org/gitlab/1.0-SNAPSHOT`	Yes

Endpoint URLs

Endpoint	Endpoint URL for `pom.xml`	Additional information
Project	`https://gitlab.example.com/api/v4/projects/<project_id>/packages/maven`	Replace `gitlab.example.com` with your domain name. Replace `<project_id>` with your project ID, found on your project’s homepage.
Group	`https://gitlab.example.com/api/v4/groups/<group_id>/-/packages/maven`	Replace `gitlab.example.com` with your domain name. Replace `<group_id>` with your group ID, found on your group’s homepage.
Instance	`https://gitlab.example.com/api/v4/packages/maven`	Replace `gitlab.example.com` with your domain name.

Edit the configuration file for publishing

You must add publishing details to the configuration file for your client.

mvn

No matter which endpoint you choose, you must have:

A project-specific URL in the distributionManagement section.
A repository and distributionManagement section.

The relevant repository section of your pom.xml in Maven should look like this:

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

The id is what you defined in settings.xml.
The <your_endpoint_url> depends on which endpoint you choose.
Replace gitlab.example.com with your domain name.

gradle

To publish a package by using Gradle:

Add the Gradle plugin maven-publish to the plugins section:

In Groovy DSL:

plugins {
    id 'java'
    id 'maven-publish'
}

In Kotlin DSL:

plugins {
    java
    `maven-publish`
}

Add a publishing section:

In Groovy DSL:

publishing {
    publications {
        library(MavenPublication) {
            from components.java
        }
    }
    repositories {
        maven {
            url "https://gitlab.example.com/api/v4/projects/<PROJECT_ID>/packages/maven"
            credentials(HttpHeaderCredentials) {
                name = "REPLACE_WITH_TOKEN_NAME"
                value = gitLabPrivateToken // the variable resides in $GRADLE_USER_HOME/gradle.properties
            }
            authentication {
                header(HttpHeaderAuthentication)
            }
        }
    }
}

In Kotlin DSL:

publishing {
    publications {
        create<MavenPublication>("library") {
            from(components["java"])
        }
    }
    repositories {
        maven {
            url = uri("https://gitlab.example.com/api/v4/projects/<PROJECT_ID>/packages/maven")
            credentials(HttpHeaderCredentials::class) {
                name = "REPLACE_WITH_TOKEN_NAME"
                value =
                    findProperty("gitLabPrivateToken") as String? // the variable resides in $GRADLE_USER_HOME/gradle.properties
            }
            authentication {
                create("header", HttpHeaderAuthentication::class)
            }
        }
    }
}

Publish a package

After you have set up the authentication and chosen an endpoint for publishing, publish a Maven package to your project.

mvn

To publish a package by using Maven:

mvn deploy

If the deploy is successful, the build success message should be displayed:

...
[INFO] BUILD SUCCESS
...

The message should also show that the package was published to the correct location:

Uploading to gitlab-maven: https://example.com/api/v4/projects/PROJECT_ID/packages/maven/com/mycompany/mydepartment/my-project/1.0-SNAPSHOT/my-project-1.0-20200128.120857-1.jar

gradle

Run the publish task:

gradle publish

Go to your project’s Packages and registries page and view the published packages.

Install a package

To install a package from the GitLab Package Registry, you must configure the remote and authenticate. When this is completed, you can install a package from a project, group, or namespace.

If multiple packages have the same name and version, when you install a package, the most recently-published package is retrieved.

mvn

To install a package by using mvn install:

Add the dependency manually to your project pom.xml file. To add the example created earlier, the XML would be:

<dependency>
  <groupId>com.mycompany.mydepartment</groupId>
  <artifactId>my-project</artifactId>
  <version>1.0-SNAPSHOT</version>
</dependency>

In your project, run the following:
```
mvn install
```

The message should show that the package is downloading from the Package Registry:

Downloading from gitlab-maven: http://gitlab.example.com/api/v4/projects/PROJECT_ID/packages/maven/com/mycompany/mydepartment/my-project/1.0-SNAPSHOT/my-project-1.0-20200128.120857-1.pom

You can also install packages by using the Maven dependency:get command directly.

In your project directory, run:
```
mvn dependency:get -Dartifact=com.nickkipling.app:nick-test-app:1.1-SNAPSHOT -DremoteRepositories=gitlab-maven::::<gitlab endpoint url>  -s <path to settings.xml>
```
- <gitlab endpoint url> is the URL of the GitLab endpoint.
- <path to settings.xml> is the path to the settings.xml file that contains the authentication details.

The repository IDs in the command(gitlab-maven) and the settings.xml file must match.

The message should show that the package is downloading from the Package Registry:

Downloading from gitlab-maven: http://gitlab.example.com/api/v4/projects/PROJECT_ID/packages/maven/com/mycompany/mydepartment/my-project/1.0-SNAPSHOT/my-project-1.0-20200128.120857-1.pom

gradle

To install a package by using gradle:

Add a dependency to build.gradle in the dependencies section:

In Groovy DSL:

dependencies {
    implementation 'com.mycompany.mydepartment:my-project:1.0-SNAPSHOT'
}

In Kotlin DSL:

dependencies {
    implementation("com.mycompany.mydepartment:my-project:1.0-SNAPSHOT")
}

In your project, run the following:
```
gradle install
```

sbt

To install a package by using sbt:

Add an inline dependency to build.sbt:

libraryDependencies += "com.mycompany.mydepartment" % "my-project" % "8.4"

In your project, run the following:
```
sbt update
```

Helpful hints

Publishing a package with the same name or version

When you publish a package with the same name and version as an existing package, the new package files are added to the existing package. You can still use the UI or API to access and view the existing package’s older assets.

To delete older package versions, consider using the Packages API or the UI.

Do not allow duplicate Maven packages

Required role changed from Developer to Maintainer in GitLab 15.0.

To prevent users from publishing duplicate Maven packages, you can use the GraphQl API or the UI.

In the UI:

On the left sidebar, select Search or go to and find your group.
Select Settings > Packages and registries.
In the Maven row of the Duplicate packages table, turn off the Allow duplicates toggle.
Optional. In the Exceptions text box, enter a regular expression that matches the names and versions of packages to allow.

Your changes are automatically saved.

Request forwarding to Maven Central

By default this feature is not available for self-managed. To make it available, an administrator can enable the feature flag named maven_central_request_forwarding. This feature is not available for SaaS users.

When a Maven package is not found in the Package Registry, the request is forwarded to Maven Central.

When the feature flag is enabled, administrators can disable this behavior in the Continuous Integration settings.

Maven forwarding is restricted to only the project level and group level endpoints. The instance level endpoint has naming restrictions that prevent it from being used for packages that don’t follow that convention and also introduces too much security risk for supply-chain style attacks.

Additional configuration for `mvn`

When using mvn, there are many ways to configure your Maven project so that it requests packages in Maven Central from GitLab. Maven repositories are queried in a specific order. By default, Maven Central is usually checked first through the Super POM, so GitLab needs to be configured to be queried before maven-central.

To ensure all package requests are sent to GitLab instead of Maven Central, you can override Maven Central as the central repository by adding a <mirror> section to your settings.xml:

<settings>
  <servers>
    <server>
      <id>central-proxy</id>
      <configuration>
        <httpHeaders>
          <property>
            <name>Private-Token</name>
            <value><personal_access_token></value>
          </property>
        </httpHeaders>
      </configuration>
    </server>
  </servers>
  <mirrors>
    <mirror>
      <id>central-proxy</id>
      <name>GitLab proxy of central repo</name>
      <url>https://gitlab.example.com/api/v4/projects/<project_id>/packages/maven</url>
      <mirrorOf>central</mirrorOf>
    </mirror>
  </mirrors>
</settings>

Create Maven packages with GitLab CI/CD

After you have configured your repository to use the Package Repository for Maven, you can configure GitLab CI/CD to build new packages automatically.

mvn

You can create a new package each time the default branch is updated.

Create a ci_settings.xml file that serves as Maven’s settings.xml file.

Add the server section with the same ID you defined in your pom.xml file. For example, use gitlab-maven as the ID:

<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>

Make sure your pom.xml file includes the following. You can either let Maven use the predefined CI/CD variables, as shown in this example, or you can hard code your server’s hostname and project’s ID.

<repositories>
  <repository>
    <id>gitlab-maven</id>
    <url>${CI_API_V4_URL}/projects/${CI_PROJECT_ID}/packages/maven</url>
  </repository>
</repositories>
<distributionManagement>
  <repository>
    <id>gitlab-maven</id>
    <url>${CI_API_V4_URL}/projects/${CI_PROJECT_ID}/packages/maven</url>
  </repository>
  <snapshotRepository>
    <id>gitlab-maven</id>
    <url>${CI_API_V4_URL}/projects/${CI_PROJECT_ID}/packages/maven</url>
  </snapshotRepository>
</distributionManagement>

Add a deploy job to your .gitlab-ci.yml file:

deploy:
  image: maven:3.6-jdk-11
  script:
    - 'mvn deploy -s ci_settings.xml'
  rules:
    - if: $CI_COMMIT_BRANCH == $CI_DEFAULT_BRANCH

Push those files to your repository.

The next time the deploy job runs, it copies ci_settings.xml to the user’s home location. In this example:

The user is root, because the job runs in a Docker container.
Maven uses the configured CI/CD variables.

gradle

You can create a package each time the default branch is updated.

Authenticate with a CI job token in Gradle.

Add a deploy job to your .gitlab-ci.yml file:

deploy:
  image: gradle:6.5-jdk11
  script:
    - 'gradle publish'
  rules:
    - if: $CI_COMMIT_BRANCH == $CI_DEFAULT_BRANCH

Commit files to your repository.

When the pipeline is successful, the Maven package is created.

Version validation

The version string is validated by using the following regex.

\A(?!.*\.\.)[\w+.-]+\z

You can experiment with the regex and try your version strings on this regular expression editor.

Useful Maven command-line options

There are some Maven command-line options that you can use when performing tasks with GitLab CI/CD.

File transfer progress can make the CI logs hard to read. Option -ntp,--no-transfer-progress was added in 3.6.1. Alternatively, look at -B,--batch-mode or lower level logging changes.

Specify where to find the pom.xml file (-f,--file):

package:
  script:
    - 'mvn --no-transfer-progress -f helloworld/pom.xml package'

Specify where to find the user settings (-s,--settings) instead of the default location. There’s also a -gs,--global-settings option:
```
package:
  script:
    - 'mvn -s settings/ci.xml package'
```

Supported CLI commands

The GitLab Maven repository supports the following CLI commands:

mvn

mvn deploy: Publish your package to the Package Registry.
mvn install: Install packages specified in your Maven project.
mvn dependency:get: Install a specific package.

gradle

gradle publish: Publish your package to the Package Registry.
gradle install: Install packages specified in your Gradle project.

Troubleshooting

To improve performance, clients cache files related to a package. If you encounter issues, clear the cache with these commands:

mvn

rm -rf ~/.m2/repository

gradle

rm -rf ~/.gradle/caches # Or replace ~/.gradle with your custom GRADLE_USER_HOME

Review network trace logs

If you are having issues with the Maven Repository, you may want to review network trace logs.

For example, try to run mvn deploy locally with a PAT token and use these options:

mvn deploy \
-Dorg.slf4j.simpleLogger.log.org.apache.maven.wagon.providers.http.httpclient=trace \
-Dorg.slf4j.simpleLogger.log.org.apache.maven.wagon.providers.http.httpclient.wire=trace

When you set these options, all network requests are logged and a large amount of output is generated.

Verify your Maven settings

If you encounter issues within CI/CD that relate to the settings.xml file, try adding an additional script task or job to verify the effective settings.

The help plugin can also provide system properties, including environment variables:

mvn-settings:
  script:
    - 'mvn help:effective-settings'

package:
  script:
    - 'mvn help:system'
    - 'mvn package'

Maven packages in the Package Registry

Publish to the GitLab Package Registry

Authenticate to the Package Registry

Edit the client configuration

Naming convention

Endpoint URLs

Edit the configuration file for publishing

Publish a package

Install a package

Helpful hints

Publishing a package with the same name or version

Do not allow duplicate Maven packages

Request forwarding to Maven Central

Additional configuration for `mvn`

Create Maven packages with GitLab CI/CD

Version validation

Useful Maven command-line options

Supported CLI commands

Troubleshooting

Review network trace logs

Verify your Maven settings

Help & feedback

Docs

Product

Feature availability and product trials

Get Help

Maven packages in the Package Registry

Publish to the GitLab Package Registry

Authenticate to the Package Registry

Edit the client configuration

Naming convention

Endpoint URLs

Edit the configuration file for publishing

Publish a package

Install a package

Helpful hints

Publishing a package with the same name or version

Do not allow duplicate Maven packages

Request forwarding to Maven Central

Additional configuration for mvn

Create Maven packages with GitLab CI/CD

Version validation

Useful Maven command-line options

Supported CLI commands

Troubleshooting

Review network trace logs

Verify your Maven settings

Help & feedback

Docs

Product

Feature availability and product trials

Get Help

Additional configuration for `mvn`