Merge branch 'aws-cognito-docs' into 'master'

Update integration docs - AWS Cognito

See merge request gitlab-org/gitlab!23909

doc/administration/auth/README.md

@@ -10,6 +10,7 @@ providers:
 
 - [Auth0](../../integration/auth0.md)
 - [Authentiq](authentiq.md)
+- [AWS Cognito](cognito.md)
 - [Azure](../../integration/azure.md)
 - [Bitbucket Cloud](../../integration/bitbucket.md)
 - [CAS](../../integration/cas.md)

doc/administration/auth/cognito.md

+# Amazon Web Services Cognito
+
+Amazon Cognito lets you add user sign-up, sign-in, and access control to your GitLab instance.
+The following documentation enables Cognito as an OAuth2 provider.
+
+## Configure AWS Cognito
+
+To enable the [AWS Cognito](https://aws.amazon.com/cognito/) OAuth2 OmniAuth provider, register your application with Cognito,
+where it will generate a Client ID and Client Secret for your application.
+Any settings you configure in the following procedure can be modified later.
+The following steps enable AWS Cognito as an authentication provider:
+
+1. Sign in to the [AWS console](https://console.aws.amazon.com/console/home).
+1. Select **Cognito** from the **Services** menu.
+1. Select **Manage User Pools**, and click the **Create a user pool** button in the top right corner.
+1. Enter the pool name and then click the **Step through settings** button.
+1. Under **How do you want your end users to sign in?**, select **Email address or phone number** and **Allow email addresses**.
+1. Under **Which standard attributes do you want to require?**, select **email**.
+1. Go to the next steps of configuration and set the rest of the settings to suit your needs - in the basic setup they are not related to GitLab configuration.
+1. In the **App clients** settings, click **Add an app client**, add **App client name** and select the **Enable username password based authentication** check box.
+1. Click **Create app client**.
+1. In the next step, you can set up AWS Lambda functions for sending emails. You can then finish creating the pool.
+1. After creating the user pool, go to **App client settings** and provide the required information:
+
+   - **Enabled Identity Providers** - select all
+   - **Callback URL** - `https://gitlab.example.com/users/auth/cognito/callback`
+     - Substitute the URL of your GitLab instance for `gitlab.example.com`
+   - **Allowed OAuth Flows** - Authorization code grant
+   - **Allowed OAuth Scopes** - `email` and `openid`
+
+1. Save changes for the app client settings.
+1. Under **Domain name** include the AWS domain name for your AWS Cognito application.
+1. Under **App Clients**, find your **App client id** and **App client secret**. These values correspond to the OAuth2 Client ID and Client Secret. Save these values.
+
+## Configure GitLab
+
+1. See [Initial OmniAuth Configuration](../../integration/omniauth.md#initial-omniauth-configuration) for initial settings.
+1. On your GitLab server, open the configuration file.
+
+   **For Omnibus installations**
+
+   ```shell
+   sudo editor /etc/gitlab/gitlab.rb
+   ```
+
+1. In the following code block, substitute the Client ID (`app_id`), Client Secret (`app_secret`), and the Amazon domain name (`site`) for your AWS Cognito application.
+Include the code block in the `/etc/gitlab/gitlab.rb` file:
+
+   ```ruby
+   gitlab_rails['omniauth_allow_single_sign_on'] = ['cognito']
+   gitlab_rails['omniauth_providers'] = [
+     {
+       "name" => "cognito",
+       "app_id" => "CLIENT ID",
+       "app_secret" => "CLIENT SECRET",
+       "args" => {
+         client_options: {
+           'site' => 'https://your_domain.auth.your_region.amazoncognito.com',
+           'authorize_url' => '/login',
+           'token_url' => '/oauth2/token',
+           'user_info_url' => '/oauth2/userInfo'
+         },
+         user_response_structure: {
+           root_path: [],
+           attributes: { nickname: 'email'}
+         },
+         name: 'cognito',
+         strategy_class: "OmniAuth::Strategies::OAuth2Generic"
+       }
+     }
+   ]
+   ```
+
+1. Save the configuration file.
+1. Save the file and [reconfigure](../restart_gitlab.md#omnibus-gitlab-reconfigure) GitLab for the changes to take effect.
+
+Your sign-in page should now display a Cognito button below the regular sign-in form.
+To begin the authentication process, click the icon, and AWS Cognito will ask the user to sign in and authorize the GitLab application.
+If successful, the user will be redirected and signed in to your GitLab instance.

doc/integration/omniauth.md

@@ -36,6 +36,7 @@ contains some settings that are common for all providers.
 - [OpenID Connect](../administration/auth/oidc.md)
 - [UltraAuth](ultra_auth.md)
 - [Salesforce](salesforce.md)
+- [AWS Cognito](../administration/auth/cognito.md)
 
 ## Initial OmniAuth Configuration