GitLab Container Registry Administration

Note: This feature was introduced in GitLab 8.8.

With the Docker Container Registry integrated into GitLab, every project can have its own space to store its Docker images.

You can read more about Docker Registry at https://docs.docker.com/registry/introduction/.

Table of Contents generated with DocToc

Enable the Container Registry
Container Registry domain configuration
- Configure Container Registry under an existing GitLab domain
- Configure Container Registry under its own domain
Disable Container Registry site-wide
Disable Container Registry per project
Disable Container Registry for new projects site-wide
Container Registry storage path
Storage limitations
Changelog

Enable the Container Registry

Omnibus GitLab installations

All you have to do is configure the domain name under which the Container Registry will listen to. Read #container-registry-domain-configuration and pick one of the two options that fits your case.

Note: The container Registry works under HTTPS by default. Using HTTP is possible but not recommended and out of the scope of this document. Read the insecure Registry documentation if you want to implement this.

Installations from source

If you have installed GitLab from source:

You will have to install Docker Registry by yourself.
After the installation is complete, you will have to configure the Registry's settings in gitlab.yml in order to enable it.
Use the sample NGINX configuration file that is found under lib/support/nginx/registry-ssl and edit it to match the host, port and TLS certs paths.

The contents of gitlab.yml are:

registry:
  enabled: true
  host: registry.gitlab.example.com
  port: 5005
  api_url: http://localhost:5000/
  key_path: config/registry.key
  path: shared/registry
  issuer: gitlab-issuer

where:

Parameter	Description
`enabled`	`true` or `false`. Enables the Registry in GitLab. By default this is `false`.
`host`	The host URL under which the Registry will run and the users will be able to use.
`port`	The port under which the external Registry domain will listen on.
`api_url`	The internal API URL under which the Registry is exposed to. It defaults to `http://localhost:5000`.
`key_path`	The private key location that is a pair of Registry's `rootcertbundle`. Read the token auth configuration documentation.
`path`	This should be the same directory like specified in Registry's `rootdirectory`. Read the storage configuration documentation. This path needs to be readable by the GitLab user, the web-server user and the Registry user. Read more in #container-registry-storage-path.
`issuer`	This should be the same value as configured in Registry's `issuer`. Read the token auth configuration documentation.

Note: GitLab does not ship with a Registry init file. Hence, restarting GitLab will not restart the Registry should you modify its settings. Read the upstream documentation on how to achieve that.

Container Registry domain configuration

There are two ways you can configure the Registry's external domain.

Either use the existing GitLab domain where in that case the Registry will have to listen on a port and reuse GitLab's TLS certificate,
or use a completely separate domain with a new TLS certificate for that domain.

Since the container Registry requires a TLS certificate, in the end it all boils down to how easy or pricey is to get a new one.

Please take this into consideration before configuring the Container Registry for the first time.

Configure Container Registry under an existing GitLab domain

If the Registry is configured to use the existing GitLab domain, you can expose the Registry on a port so that you can reuse the existing GitLab TLS certificate.

Assuming that the GitLab domain is https://gitlab.example.com and the port the Registry is exposed to the outside world is 4567, here is what you need to set in gitlab.rb or gitlab.yml if you are using Omnibus GitLab or installed GitLab from source respectively.

Omnibus GitLab installations

Your /etc/gitlab/gitlab.rb should contain the Registry URL as well as the path to the existing TLS certificate and key used by GitLab:
```
registry_external_url 'https://gitlab.example.com:4567'
```
Note how the registry_external_url is listening on HTTPS under the existing GitLab URL, but on a different port.

If your TLS certificate is not in /etc/gitlab/ssl/gitlab.example.com.crt and key not in /etc/gitlab/ssl/gitlab.example.com.key uncomment the lines below:
```
registry_nginx['ssl_certificate'] = "/path/to/certificate.pem"
registry_nginx['ssl_certificate_key'] = "/path/to/certificate.key"
```
Save the file and reconfigure GitLab for the changes to take effect.

Installations from source

Open /home/git/gitlab/config/gitlab.yml, find the registry entry and configure it with the following settings:
```
registry:
  enabled: true
  host: gitlab.example.com
  port: 4567
```
Save the file and restart GitLab for the changes to take effect.
Make the relevant changes in NGINX as well (domain, port, TLS certificates path).

Users should now be able to login to the Container Registry with their GitLab credentials using:

docker login gitlab.example.com:4567

Configure Container Registry under its own domain

If the Registry is configured to use its own domain, you will need a TLS certificate for that specific domain (e.g., registry.example.com) or maybe a wildcard certificate if hosted under a subdomain of your existing GitLab domain (e.g., registry.gitlab.example.com).

Let's assume that you want the container Registry to be accessible at https://registry.gitlab.example.com.

Omnibus GitLab installations

Place your TLS certificate and key in /etc/gitlab/ssl/registry.gitlab.example.com.crt and /etc/gitlab/ssl/registry.gitlab.example.com.key and make sure they have correct permissions:
```
chmod 600 /etc/gitlab/ssl/registry.gitlab.example.com.*
```
Once the TLS certificate is in place, edit /etc/gitlab/gitlab.rb with:
```
registry_external_url 'https://registry.gitlab.example.com'
```
Note how the registry_external_url is listening on HTTPS.
Save the file and reconfigure GitLab for the changes to take effect.

Note: If you have a wildcard certificate, you need to specify the path to the certificate in addition to the URL, in this case /etc/gitlab/gitlab.rb will look like:
registry_nginx['ssl_certificate'] = "/etc/gitlab/ssl/certificate.pem"
registry_nginx['ssl_certificate_key'] = "/etc/gitlab/ssl/certificate.key"

Installations from source

Open /home/git/gitlab/config/gitlab.yml, find the registry entry and configure it with the following settings:
```
registry:
  enabled: true
  host: registry.gitlab.example.com
```
Save the file and restart GitLab for the changes to take effect.
Make the relevant changes in NGINX as well (domain, port, TLS certificates path).

Users should now be able to login to the Container Registry using their GitLab credentials:

docker login registry.gitlab.example.com

Disable Container Registry site-wide

Note: Disabling the Registry in the Rails GitLab application as set by the following steps, will not remove any existing Docker images. This is handled by the Registry application itself.

Omnibus GitLab

Open /etc/gitlab/gitlab.rb and set registry['enable'] to false:
```
registry['enable'] = false
```
Save the file and reconfigure GitLab for the changes to take effect.

Installations from source

Open /home/git/gitlab/config/gitlab.yml, find the registry entry and set enabled to false:
```
registry:
  enabled: false
```
Save the file and restart GitLab for the changes to take effect.

Disable Container Registry per project

If Registry is enabled in your GitLab instance, but you don't need it for your project, you can disable it from your project's settings. Read the user guide on how to achieve that.

Disable Container Registry for new projects site-wide

If the Container Registry is enabled, then it will be available on all new projects. To disable this function and let the owners of a project to enable the Container Registry by themselves, follow the steps below.

Omnibus GitLab installations

Edit /etc/gitlab/gitlab.rb and add the following line:

gitlab_rails['gitlab_default_projects_features_container_registry'] = false

Save the file and reconfigure GitLab for the changes to take effect.

Installations from source

Open /home/git/gitlab/config/gitlab.yml, find the default_projects_features entry and configure it so that container_registry is set to false:

## Default project features settings
default_projects_features:
  issues: true
  merge_requests: true
  wiki: true
  snippets: false
  builds: true
  container_registry: false

Save the file and restart GitLab for the changes to take effect.

Container Registry storage path

To change the storage path where Docker images will be stored, follow the steps below.

This path is accessible to:

the user running the Container Registry daemon,
the user running GitLab

Warning You should confirm that all GitLab, Registry and web server users have access to this directory.

Omnibus GitLab installations

The default location where images are stored in Omnibus, is /var/opt/gitlab/gitlab-rails/shared/registry. To change it:

Edit /etc/gitlab/gitlab.rb:

gitlab_rails['registry_path'] = "/path/to/registry/storage"

Save the file and reconfigure GitLab for the changes to take effect.

Installations from source

The default location where images are stored in source installations, is /home/git/gitlab/shared/registry. To change it:

Open /home/git/gitlab/config/gitlab.yml, find the registry entry and change the path setting:
```
registry:
  path: shared/registry
```
Save the file and restart GitLab for the changes to take effect.

Storage limitations

Currently, there is no storage limitation, which means a user can upload an infinite amount of Docker images with arbitrary sizes. This setting will be configurable in future releases.

Changelog

GitLab 8.8 (source docs)

GitLab Container Registry feature was introduced.