---
stage: Enablement
group: Distribution
info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#designated-technical-writers
type: reference
---

# Environment variables

GitLab exposes certain environment variables which can be used to override
their defaults values.

People usually configure GitLab with `/etc/gitlab/gitlab.rb` for Omnibus
installations, or `gitlab.yml` for installations from source.

You can use the following environment variables to override certain values:

## Supported environment variables

| Variable                                   | Type    | Description                                                                                             |
|--------------------------------------------|---------|---------------------------------------------------------------------------------------------------------|
| `DATABASE_URL`                             | string  | The database URL; is of the form: `postgresql://localhost/blog_development`.                            |
| `ENABLE_BOOTSNAP`                          | string  | Enables Bootsnap for speeding up initial Rails boot (`1` to enable).                                    |
| `GITLAB_CDN_HOST`                          | string  | Sets the base URL for a CDN to serve static assets (for example, `//mycdnsubdomain.fictional-cdn.com`). |
| `GITLAB_EMAIL_DISPLAY_NAME`                | string  | The name used in the **From** field in emails sent by GitLab.                                           |
| `GITLAB_EMAIL_FROM`                        | string  | The email address used in the **From** field in emails sent by GitLab.                                  |
| `GITLAB_EMAIL_REPLY_TO`                    | string  | The email address used in the **Reply-To** field in emails sent by GitLab.                              |
| `GITLAB_EMAIL_SUBJECT_SUFFIX`              | string  | The email subject suffix used in emails sent by GitLab.                                                 |
| `GITLAB_HOST`                              | string  | The full URL of the GitLab server (including `http://` or `https://`).                                  |
| `GITLAB_ROOT_PASSWORD`                     | string  | Sets the password for the `root` user on installation.                                                  |
| `GITLAB_SHARED_RUNNERS_REGISTRATION_TOKEN` | string  | Sets the initial registration token used for runners.                                                   |
| `GITLAB_UNICORN_MEMORY_MAX`                | integer | The maximum memory threshold (in bytes) for the [unicorn-worker-killer](operations/unicorn.md#unicorn-worker-killer).      |
| `GITLAB_UNICORN_MEMORY_MIN`                | integer | The minimum memory threshold (in bytes) for the [unicorn-worker-killer](operations/unicorn.md#unicorn-worker-killer).      |
| `RAILS_ENV`                                | string  | The Rails environment; can be one of `production`, `development`, `staging`, or `test`.                 |
| `UNSTRUCTURED_RAILS_LOG`                   | string  | Enables the unstructured log in addition to JSON logs (defaults to `true`).                             |

## Complete database variables

The recommended method for specifying your database connection information is
to set the `DATABASE_URL` environment variable. This variable contains
connection information (`adapter`, `database`, `username`, `password`, `host`,
and `port`), but no behavior information (`encoding` or `pool`). If you don't
want to use `DATABASE_URL`, or want to set database behavior information,
either:

- Copy the template file, `cp config/database.yml.env config/database.yml`.
- Set a value for some `GITLAB_DATABASE_XXX` variables.

The list of `GITLAB_DATABASE_XXX` variables that you can set is:

| Variable                    | Default value                  | Overridden by `DATABASE_URL`? |
|-----------------------------|--------------------------------|-------------------------------|
| `GITLAB_DATABASE_ADAPTER`   | `postgresql`                   | **{check-circle}** Yes        |
| `GITLAB_DATABASE_DATABASE`  | `gitlab_#{ENV['RAILS_ENV']`    | **{check-circle}** Yes        |
| `GITLAB_DATABASE_ENCODING`  | `unicode`                      | **{dotted-circle}** No        |
| `GITLAB_DATABASE_HOST`      | `localhost`                    | **{check-circle}** Yes        |
| `GITLAB_DATABASE_PASSWORD`  | _none_                         | **{check-circle}** Yes        |
| `GITLAB_DATABASE_POOL`      | `10`                           | **{dotted-circle}** No        |
| `GITLAB_DATABASE_PORT`      | `5432`                         | **{check-circle}** Yes        |
| `GITLAB_DATABASE_USERNAME`  | `root`                         | **{check-circle}** Yes        |

## Adding more variables

We welcome merge requests to make more settings configurable by using variables.
Make changes to the `config/initializers/1_settings.rb` file, and use the
naming scheme `GITLAB_#{name in 1_settings.rb in upper case}`.

## Omnibus configuration

To set environment variables, follow [these instructions](https://docs.gitlab.com/omnibus/settings/environment-variables.html).

It's possible to preconfigure the GitLab Docker image by adding the environment
variable `GITLAB_OMNIBUS_CONFIG` to the `docker run` command.
For more information, see the [Pre-configure Docker container](https://docs.gitlab.com/omnibus/docker/#pre-configure-docker-container)
section of the Omnibus GitLab documentation.
