Merge branch 'registry_admin_docs' into 'master'

Docker container registry configuration docs.

Part of gitlab-org/omnibus-gitlab!764 and gitlab-org/gitlab-ce!4040

See merge request !4141

2 files changed, 376 insertions, 0 deletions

diff --git a/doc/README.md b/doc/README.md
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@@ -44,6 +44,7 @@
 - [Monitoring uptime](monitoring/health_check.md) Check the server status using the health check endpoint
 - [Sidekiq Troubleshooting](administration/troubleshooting/sidekiq.md) Debug when Sidekiq appears hung and is not processing jobs
 - [High Availability](administration/high_availability/README.md) Configure multiple servers for scaling or high availability
+- [Container Registry](administration/container_registry.md) Configure Docker Registry with GitLab
 
 ## Contributor documentation
 
diff --git a/doc/administration/container_registry.md b/doc/administration/container_registry.md
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+# GitLab Container Registry Administration
+
+> **Note:**
+This feature was [introduced][ce-4040] 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/.
+
+---
+
+<!-- START doctoc generated TOC please keep comment here to allow auto update -->
+<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
+**Table of Contents**  *generated with [DocToc](https://github.com/thlorenz/doctoc)*
+
+- [Enable the Container Registry](#enable-the-container-registry)
+- [Container Registry domain configuration](#container-registry-domain-configuration)
+    - [Configure Container Registry under an existing GitLab domain](#configure-container-registry-under-an-existing-gitlab-domain)
+    - [Configure Container Registry under its own domain](#configure-container-registry-under-its-own-domain)
+- [Disable Container Registry site-wide](#disable-container-registry-site-wide)
+- [Disable Container Registry per project](#disable-container-registry-per-project)
+- [Disable Container Registry for new projects site-wide](#disable-container-registry-for-new-projects-site-wide)
+- [Container Registry storage path](#container-registry-storage-path)
+- [Storage limitations](#storage-limitations)
+- [Changelog](#changelog)
+
+<!-- END doctoc generated TOC please keep comment here to allow auto update -->
+
+## 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](#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][docker-insecure] if you want to
+implement this.
+
+---
+
+**Installations from source**
+
+If you have installed GitLab from source:
+
+1. You will have to [install Docker Registry][registry-deploy] by yourself.
+1. After the installation is complete, you will have to configure the Registry's
+   settings in `gitlab.yml` in order to enable it.
+1. Use the sample NGINX configuration file that is found under
+   [`lib/support/nginx/registry-ssl`][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][token-config]. |
+| `path`    | This should be the same directory like specified in Registry's `rootdirectory`. Read the [storage configuration documentation][storage-config]. 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](#container-registry-storage-path). |
+| `issuer`  | This should be the same value as configured in Registry's `issuer`. Read the [token auth configuration documentation][token-config]. |
+
+>**Note:**
+GitLab does not ship with a Registry init file. Hence, [restarting GitLab][restart 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][existing-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][new-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**
+
+1. 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:
+
+    ```ruby
+    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:
+
+    ```ruby
+    registry_nginx['ssl_certificate'] = "/path/to/certificate.pem"
+    registry_nginx['ssl_certificate_key'] = "/path/to/certificate.key"
+    ```
+
+1. Save the file and [reconfigure GitLab][] for the changes to take effect.
+
+---
+
+**Installations from source**
+
+1. 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
+    ```
+
+1. Save the file and [restart GitLab][] for the changes to take effect.
+1. 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:
+
+```bash
+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**
+
+1. 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:
+
+    ```bash
+    chmod 600 /etc/gitlab/ssl/registry.gitlab.example.com.*
+    ```
+
+1. Once the TLS certificate is in place, edit `/etc/gitlab/gitlab.rb` with:
+
+    ```ruby
+    registry_external_url 'https://registry.gitlab.example.com'
+    ```
+
+    Note how the `registry_external_url` is listening on HTTPS.
+
+1. 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:
+>
+```ruby
+registry_nginx['ssl_certificate'] = "/etc/gitlab/ssl/certificate.pem"
+registry_nginx['ssl_certificate_key'] = "/etc/gitlab/ssl/certificate.key"
+```
+
+---
+
+**Installations from source**
+
+1. 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
+    ```
+
+1. Save the file and [restart GitLab][] for the changes to take effect.
+1. 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:
+
+```bash
+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**
+
+1. Open `/etc/gitlab/gitlab.rb` and set `registry['enable']` to `false`:
+
+    ```ruby
+    registry['enable'] = false
+    ```
+
+1. Save the file and [reconfigure GitLab][] for the changes to take effect.
+
+---
+
+**Installations from source**
+
+1. Open `/home/git/gitlab/config/gitlab.yml`, find the `registry` entry and
+   set `enabled` to `false`:
+
+    ```
+    registry:
+      enabled: false
+    ```
+
+1. 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**
+
+1. Edit `/etc/gitlab/gitlab.rb` and add the following line:
+
+    ```ruby
+    gitlab_rails['gitlab_default_projects_features_container_registry'] = false
+    ```
+
+1. Save the file and [reconfigure GitLab][] for the changes to take effect.
+
+---
+
+**Installations from source**
+
+1. 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
+    ```
+
+1. 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:
+
+1. Edit `/etc/gitlab/gitlab.rb`:
+
+    ```ruby
+    gitlab_rails['registry_path'] = "/path/to/registry/storage"
+    ```
+
+1. 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:
+
+1. Open `/home/git/gitlab/config/gitlab.yml`, find the `registry` entry and
+   change the `path` setting:
+
+    ```
+    registry:
+      path: shared/registry
+    ```
+
+1. 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][8-8-docs])**
+
+- GitLab Container Registry feature was introduced.
+
+[reconfigure gitlab]: restart_gitlab.md#omnibus-gitlab-reconfigure
+[restart gitlab]: restart_gitlab.md#installations-from-source
+[wildcard certificate]: https://en.wikipedia.org/wiki/Wildcard_certificate
+[ce-4040]: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4040
+[docker-insecure]: https://docs.docker.com/registry/insecure/
+[registry-deploy]: https://docs.docker.com/registry/deploying/
+[storage-config]: https://docs.docker.com/registry/configuration/#storage
+[token-config]: https://docs.docker.com/registry/configuration/#token
+[8-8-docs]: https://gitlab.com/gitlab-org/gitlab-ce/blob/8-8-stable/doc/administration/container_registry.md
+[registry-ssl]: https://gitlab.com/gitlab-org/gitlab-ce/blob/master/lib/support/nginx/registry-ssl
+[existing-domain]: #configure-container-registry-under-an-existing-gitlab-domain
+[new-domain]: #configure-container-registry-under-its-own-domain