# GitLab (self-hosted) === ***Note:** This guide was written before the renaming. Just replace `HackMD` with `CodiMD` in your mind :smile: thanks!* 1. Sign in to your GitLab 2. Navigate to the application management page at `https://your.gitlab.domain/admin/applications` (admin permissions required) 3. Click **New application** to create a new application and fill out the registration form: ![New GitLab application](images/auth/gitlab-new-application.png) 4. Click **Submit** 5. In the list of applications select **HackMD**. Leave that site open to copy the application ID and secret in the next step. ![Application: HackMD](images/auth/gitlab-application-details.png) 6. In the `docker-compose.yml` add the following environment variables to `app:` `environment:` ``` - HMD_DOMAIN=your.hackmd.domain - HMD_URL_ADDPORT=443 - HMD_PROTOCOL_USESSL=true - HMD_GITLAB_BASEURL=https://your.gitlab.domain - HMD_GITLAB_CLIENTID=23462a34example99XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX - HMD_GITLAB_CLIENTSECRET=5532e9dexamplXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX ``` 7. Run `docker-compose up -d` to apply your settings. 8. Sign in to your HackMD using your GitLab ID: ![Sign in via GitLab](images/auth/gitlab-sign-in.png)