GitLab
You can use Buildkite to run builds on GitLab commits.
On this page:
gitlab.com repositories
If you are hosting your repositories on gitlab.com enter your gitlab.com repository URL when you create your pipeline in Buildkite (e.g. git@gitlab.com:your/repo.git) and follow the instructions provided on that page to set up webhooks.
The webhook setup instructions are also available from the GitLab section of the Pipeline Settings.
Self-hosted GitLab repositories
The earliest supported version of GitLab is 7.4.
On the Organization Settings page, find the GitLab (Self Hosted) section. Select your GitLab edition (Community or Enterprise), and enter the URL to your GitLab installation (e.g. https://git.mycompany.com).
You can optionally specify a list of IP addresses to restrict where builds can be triggered from. This field accepts a space separated list of networks in CIDR notation.
Click Save GitLab Settings before leaving this page.
Create a new pipeline on Buildkite using your GitLab repository's URL (e.g. git@git.mycompany.com:your/repo.git) and follow the instructions on the pipeline creation page.