Awesome

GitLab Merge Request Builder Plugin

A plugin that allows Jenkins to build merge requests.

This plugin fetches the source and target branches of a GitLab merge request and makes them available to your build via build parameters. Once the build completes, Jenkins will leave a comment on the merge request indicating whether the merge request was successful.

Supported GitLab Versions

GitLab version < 8.1: use v1.2.4 of this plugin
GitLab version >= 8.1 < 11: use v2.0.1 of this plugin
GitLab version >= 11: use the latest version of this plugin

Prerequisites

Whilst there is no explicit dependency on the Git plugin, it's strongly recommended that you install it since Jenkins will be unable to fetch the source code for your project.

Installation

Ensure that a Jenkins user exists within GitLab and has access to the repository.
- For GitLab version < 8.4.X: ensure that the user has Reporter level access to the project.
- For GitLab version >= 8.4.X: ensure that the user has Developer level access to the project.
- Please note that if you would like to use the Auto-merge feature Jenkins needs to have Developer access to the project.
Install the plugin in Jenkins.
- The plugin is hosted on the Jenkins Plugin repository
- Go to Jenkins -> Manage Plugins -> Available
- Search for GitLab Merge Request Builder
- And install it
- Ensure you restart Jenkins
Go to Manage Jenkins -> Configure System -> GitLab Merge Request Builder
Set the GitLab Host URL to the base URL of your GitLab server
Set your Jenkins Username for the Jenkins user (defaults to jenkins)
Set your Jenkins API Token for the Jenkins user. This can be found by logging into GitLab as Jenkins and going to the user profile section.
Set/change any of the other available parameters as necessary. If you host GitLab over an SSL connection you may want to enable ignoring certificate errors.
Save to preserve your changes.
Go to Manage Jenkins -> Configure Global Security and set Markup Formatter to Safe HTML. It will make Jenkins display links in build history properly.

Webhooks

Set GitLab webhooks to use {server}/gitlab-webhook/start
Ensure 'Merge Request' checkbox is ticked

Creating a Job

Create a new job by going to New Job
Set the Project Name
Feel free to specify the GitHub Project URL as the URL for the GitLab project (if you have the GitHub plugin installed)
In the Source Code Management section:
- Click Git and enter your Repository URL and in Advanced set its Name to origin
- For merge requests from forked repositories add another repository with Repository URL ${gitlabSourceRepository} and in Advanced set Name to ${gitlabSourceName}
- In Branch Specifier enter refs/remotes/origin/${gitlabSourceBranch} or for merge requests from forked repositories enter ${gitlabSourceName}/${gitlabSourceBranch}
- In the Additional Behaviours section:
  - Click the Add drop down button and the Merge before build item
  - Specify the name of the repository as origin (if origin corresponds to GitLab) and enter the Branch to merge to as ${gitlabTargetBranch}
  - Ensure Prune stale remote-tracking branches is not added
In the Build Triggers section:
- Check the GitLab Merge Requests Builder
- Enter the GitLab Project Path, this might be something like your_group/your_project for GitLab URL http://git.tld/your_group/your_project
- The Target Branch Regex may be configured to whitelist this job for certain target branches. If left empty, every valid merge request for the configured project path will trigger this job.
- The Use HTTP(S) URL checkbox should be used if you want Jenkins to clone/fetch using HTTP(S) instead of SSH.
Configure any other pre build, build or post build actions as necessary
Save to preserve your changes

Default Filters

Assignee Filter is defaulted to 'jenkins' only MRs that have been assigned to a 'jenkins' user will auto-start
Label Filter is defaulted to 'Build' only MRs that have been given the label 'Build' will auto-start

Changing any of the filters to an empty string will remove the filters

Manual Triggers

You can trigger a job a manually by clicking This build is parameterized and adding the relevant build parameters. These include:

gitlabSourceRepository (for MRs from forked repos)
gitlabSourceName (for MRs from forked repos)
gitlabSourceBranch
gitlabTargetBranch
gitlabMergeRequestId

Note: a manually triggered build will not add build triggered/succeeded/failed comments to the merge request. Note: You should ensure that the 'Global Config user.name Value' and 'Global Config user.email Value' are both set for your git plugin. In some cases, you will get an error indicating that a branch cannot be merged if these are not set.

Environment variables

The plugin will contribute some environment variables to the build.

gitlabMergeRequestId
gitlabMergeRequestIid
gitlabSourceName
gitlabSourceRepository
gitlabSourceBranch
gitlabTargetBranch
gitlabTitle
gitlabDescription
gitlabSourceProjectId
gitlabTargetProjectId
gitlabLastCommitId

Contributing

Check out the latest master to make sure the feature hasn't been implemented or the bug hasn't been fixed yet
Check out the issue tracker to make sure someone already hasn't requested it and/or contributed it
Fork the project
Start a feature/bugfix branch
Commit and push until you are happy with your contribution
Make sure to add tests for it. This is important so I don't break it in a future version unintentionally.
Please try not to mess with the version, or history. If you want to have your own version, or is otherwise necessary, that is fine, but please isolate to its own commit so I can cherry-pick around it.