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GitLab CI/CD integration overview

3 weeks ago11 min read
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This page walks you through integrating a GitLab project with CircleCI. The sections below introduce you to concepts and ways to manage CI/CD (continuous integration and continuous delivery) pipelines for your GitLab project. CircleCI features that are in development for GitLab projects are detailed in the Coming soon section.

What is GitLab CI/CD?

GitLab CI/CD allows you to build, test (continuous integration) and deploy (continuous deployment, continuous delivery) your projects each time a developer pushes a change to the codebase, and/or when a merge request is created. As an alternative, you can integrate with CircleCI to manage your CI/CD pipelines. If you use GitLab (SaaS or Self-managed) for version control and code storage, GitLab CI/CD is enabled for your project by default.

Integrate with CircleCI to access features for automated software delivery:

GitLab CI/CD integration with CircleCI introduces the concept of "standalone" projects that are not specific to a VCS. This is a change from the way GitHub and Bitbucket projects are currently integrated.

Steps to integrate GitLab projects with CircleCI

Follow the steps on the Sign up and try CircleCI page to connect your GitLab account, which creates your CircleCI organization.

When you connect a repo with your CircleCI project, behind the scenes, CircleCI is registering a webhook within your GitLab repository. You may verify this once you have successfully created the project by navigating to your repository’s Settings > Webhooks page.

The following limits are currently in place for GitLab integrations:

  • Each user can create up to three organizations.

  • Each organization under a Free plan can have up to 10 projects.

If you need more organizations or projects, consider upgrading to a Paid plan, or contact our Support team.

Trigger a pipeline in CircleCI

Each time you push changes to your GitLab repository, a new pipeline is triggered and you should see it running for the project within the CircleCI web app.

Successful pipeline run

Editing an existing CircleCI configuration within the web app is not currently available. You may make further changes to the config in your GitLab repo.

Committing further changes in your repo will automatically trigger a pipeline. However, manually triggering a pipeline from the CircleCI web app is also not available at this time.

Project settings - GitLab

Within CircleCI, a project integrated from GitLab can have one or more configurations, which are pipeline definitions. Configurations include, but are not limited to, a .circleci/config.yml file in your repo.

A project can have one or more triggers, which are events from a source of change. Triggers include, but are not limited to, a VCS. A trigger determines which configuration should be used to start a pipeline.

The following settings are found by clicking the Project Settings button within your project. At this time, both configurations and triggers are limited to GitLab integrations.

People

Project roles give control over which users have access to which projects within an organization. This enables teams to have limited access to only their projects, while managers and others can have broader organizational access. The access options are:

  • Admin: Read and write access to the project and all settings and ability to manage other users' access.

  • Contributor: Read and write access to the project and some settings.

  • Viewer: Read only access to the project and some settings.

For a complete list of permissions, see the Roles and permissions overview page.

Configuration

Currently, you can add or delete a configuration source for your project. If you followed the steps above to connect GitLab, a GitLab configuration source has been automatically added for you.

For GitLab Self-managed, you are able to select any instance that you have previously added as a configuration source. If you wish to set a different feature branch or repository from a self-managed instance as a new configuration source, you will first need to add a new connection via your Organization Settings. In either case, you will also need to enter your personal access token again to authorize this connection.

Once you define a configuration source, you can set up a trigger that points to that configuration.

Configuration setup page

Triggers

The scheduled pipelines feature is not currently available for use with GitLab. GitLab triggers are described below, including how to use filters to trigger pipelines based on certain conditions.

Add a trigger that specifies which configuration source starts a pipeline. If you followed the steps above to connect GitLab, a trigger set with GitLab as the configuration source has been automatically added for you.

Trigger setup page

Triggers and trigger rules determine how CircleCI handles events from the source of change, in this case, GitLab.

When a trigger is created, CircleCI registers a webhook with GitLab. Push events from GitLab are sent to CircleCI. CircleCI then uses the event data to determine if a pipeline should run, and if so, which pipeline should be run.

In addition to a configuration source, each trigger includes the webhook URL, and in this scenario, a CircleCI-created GitLab token. The webhook URL and GitLab token are used to securely register the webhook within GitLab in order to receive push events from your GitLab repo.

Trigger details

Trigger filters allow you to determine when a trigger should initiate a build based on the parameters provided by Gitlab’s webhook. CircleCI provides some common options, for example, only build on merge requests, but you can also build your own rules using the custom filter option. For example, a custom filter would allow you to only build on a specific branch or user.

Trigger details

Advanced

  • You can enable dynamic configuration using setup workflows in CircleCI. To learn about dynamic configuration, read the Dynamic configuration guide.

  • At this time, the Free and Open Source setting is not currently supported, but there are plans to make this available in the future.

  • At this time, auto-cancel redundant workflows is not supported. Refer to the Auto cancelling section of the skip or cancel jobs and workflows page for more details.

GitLab project SSH keys

When creating a GitLab-based project in CircleCI, an SSH key is created, which is used to check out code from your repo. Each configuration you create generates a new SSH key to access the code in the repo associated with that configuration. At this time, only Additional SSH Keys are applicable to GitLab projects.

Create GitLab SSH key

  1. Create an SSH key-pair by following the GitLab instructions. When prompted to enter a passphrase, do not enter one (below is one example command to generate a key on macOS):

      ssh-keygen -t ed25519 -C "your_email@example.com"

  2. Go to your project on GitLab and navigate to Settings > Repository, and expand the Deploy keys section. Enter a title in the "Title" field, then copy and paste the public key you created in step 1. Check Grant write permissions to this key box, then click Add key.

  3. Go to your project settings in the CircleCI app, select SSH Keys, and Add SSH key. In the "Hostname" field, enter gitlab.com and add the private key you created in step 1. Then click Add SSH Key.

  4. In your .circleci/config.yml file, add the fingerprint to a job using the add_ssh_keys key:

      version: 2.1

  jobs:
    deploy-job:
      steps:
        - add_ssh_keys:
            fingerprints:
              - "SO:ME:FIN:G:ER:PR:IN:T"

When you push to your GitLab repository from a job, CircleCI will use the SSH key you added.

For more information on SSH keys, please visit the Adding an SSH key to CircleCI page.

Organization settings - GitLab

For GitLab integrations, organizations and users are managed independently from your VCS. Organizations and users are considered CircleCI organizations and users, with their own roles and permissions that do not rely on those defined in your VCS.

To manage settings at the organization level, click Organization Settings in the CircleCI web app sidebar.

People

Add or remove users, and manage user roles for the organization as well as user invites. See the Roles and permissions overview page for full details.

Integrations (GitLab Self-managed only)

For GitLab Self-managed organizations, you may connect additional self-managed instances to be integrated with your organization.

  1. Navigate to Integrations within Organization Settings to add a new instance.

    Add a new self-managed instance on the Integrations page

  2. You will need to enter the instance URL, as described in the Sign up section above.

For GitLab.com, account integrations can be managed under your user settings.

Establish the authenticity of an SSH host

For GitLab self-managed instances, it is necessary to add the SSH host keys to a "known hosts" file (~/.ssh/known_hosts) so that CircleCI can verify that the host it is connecting to is authentic. The known_hosts input stores your instance’s public host keys so CircleCI jobs can verify the remote host’s identity when checking out code.

SSH keys for remote servers can be fetched by running ssh-keyscan <host>, for example, ssh-keyscan test-gitlab.circleci.com.

When retrieving the host keys, you can confirm that you have the correct key by checking its fingerprints. You can check the fingerprints found in the Instance Configuration section of your self-managed instance’s Help pages ( this Instance Configuration page shows an example).

Roles and permissions

CircleCI users have different abilities depending on assigned roles in a particular organization. For a detailed list of CircleCI org and project roles and associated permissions, see the Roles and permissions page.

User settings

Account integrations

In the User Settings section of your CircleCI user profile, you have the ability to enable multiple account integrations.

User account integrations page

The ability to connect to multiple account integrations on CircleCI allows you to:

  • Easily access all source controls on your account

  • Use all authentication methods available on CircleCI

Deprecated system environment variables

There are a number of built-in environment variables that are not available in GitLab-based projects. VCS support for each environment variable is indicated in the Built-in environment variables table on the Project values and variables page. If your pipelines need these environment variables, we recommend you use suitable replacements from the available pipeline values.

Coming soon

The following sections are features of CircleCI which are not currently fully supported for GitLab. These features are planned for future releases.

Account integrations

There is currently no method to manage the connection with GitLab outside of the project setup, trigger, and configuration settings. CircleCI is working on enabling users to manage their users’ GitLab identity as part of their user profile’s account integration settings.

Auto-cancel redundant workflows

Auto-cancel redundant workflows is not currently supported. It is often used to remove noise from the pipeline page and lower the time to feedback for a commit. Refer to the Skip or cancel jobs and workflows page for more details.

Passing secrets to forked pull requests

Passing secrets to forked pull requests is not a currently supported option for GitLab integrations.

Stop building

GitLab integrations do not currently support the Stop Building option that can normally be found in Project settings. The recommendation is to delete your webhooks in your GitLab repo if you no longer want a CircleCI pipeline to run.

SSH rerun

SSH reruns are not currently supported for GitLab projects. This feature is in development and will be available soon.

Additional SSH keys only

Deploy keys and user keys are not used by GitLab integrations. GitLab keys are stored in Project Settings > Additional SSH Keys. However, CircleCI does not recommend manually managing your SSH keys for code checkout. Instead, use the Set Up Project option, or Project Settings > Configuration, to maintain connections to your repository.

Free and open source setting

Open source plans are not currently available to GitLab customers. CircleCI will keep the open source community up to date as work continues to support this.

Test Insights

Test Insights is currently not supported for GitLab customers.

Badges

The status badge and Insights snapshot badge features are not currently supported for GitLab projects.

Next Steps

Relevant GitLab articles

Help make this document better

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