Added omniauth-auth0 Gem + Applicable Documentation.

CHANGELOG

@@ -15,6 +15,7 @@ v 8.6.0 (unreleased)
   - Update `omniauth-saml` to 1.5.0 to allow for custom response attributes to be set
   - Memoize @group in Admin::GroupsController (Yatish Mehta)
   - Indicate how much an MR diverged from the target branch (Pierre de La Morinerie)
+  - Added omniauth-auth0 Gem (Daniel Carraro)
   - Strip leading and trailing spaces in URL validator (evuez)
   - Add "last_sign_in_at" and "confirmed_at" to GET /users/* API endpoints for admins (evuez)
   - Return empty array instead of 404 when commit has no statuses in commit status API

Gemfile

@@ -22,6 +22,7 @@ gem 'devise',                 '~> 3.5.4'
 gem 'devise-async',           '~> 0.9.0'
 gem 'doorkeeper',             '~> 2.2.0'
 gem 'omniauth',               '~> 1.3.1'
+gem 'omniauth-auth0',         '~> 1.4.1'
 gem 'omniauth-azure-oauth2',  '~> 0.0.6'
 gem 'omniauth-bitbucket',     '~> 0.0.2'
 gem 'omniauth-cas3',          '~> 1.1.2'

Gemfile.lock

@@ -498,6 +498,8 @@ GEM
     omniauth (1.3.1)
       hashie (>= 1.2, < 4)
       rack (>= 1.0, < 3)
+    omniauth-auth0 (1.4.1)
+      omniauth-oauth2 (~> 1.1)
     omniauth-azure-oauth2 (0.0.6)
       jwt (~> 1.0)
       omniauth (~> 1.0)
@@ -973,6 +975,7 @@ DEPENDENCIES
   oauth2 (~> 1.0.0)
   octokit (~> 3.8.0)
   omniauth (~> 1.3.1)
+  omniauth-auth0 (~> 1.4.1)
   omniauth-azure-oauth2 (~> 0.0.6)
   omniauth-bitbucket (~> 0.0.2)
   omniauth-cas3 (~> 1.1.2)

config/gitlab.yml.example

@@ -357,6 +357,12 @@ production: &base
       #       crowd_server_url: 'CROWD SERVER URL',
       #       application_name: 'YOUR_APP_NAME',
       #       application_password: 'YOUR_APP_PASSWORD' } }
+      #
+      # - { name: 'auth0',
+      #     args: {
+      #       client_id: 'YOUR_AUTH0_CLIENT_ID',
+      #       client_secret: 'YOUR_AUTH0_CLIENT_SECRET',
+      #       namespace: 'YOUR_AUTH0_DOMAIN' } }
 
     # SSO maximum session duration in seconds. Defaults to CAS default of 8 hours.
     # cas3:

doc/integration/auth0.md

+# Auth0 OmniAuth Provider
+
+To enable the Auth0 OmniAuth provider, you must create an Auth0 account, and an
+application.
+
+1. Sign in to the [Auth0 Console](https://manage.auth0.com). If you need to
+create an account, you can do so at the same link.
+
+1. Select "New App/API".
+
+1. Provide the Application Name ('GitLab' works fine).
+
+1. Once created, you should see the Quick Start options. Disregard them and
+select 'Settings' above the Quick Start options.
+
+1. At the top of the Settings screen, you should see your Domain, Client ID and
+Client Secret. Take note of these as you'll need to put them in the
+configuration file. For example:
+    - Domain: `test1234.auth0.com`
+    - Client ID: `t6X8L2465bNePWLOvt9yi41i`
+    - Client Secret: `KbveM3nqfjwCbrhaUy_gDu2dss8TIlHIdzlyf33pB7dEK5u_NyQdp65O_o02hXs2`
+
+1. Fill in the Allowed Callback URLs:
+    - http://`YOUR_GITLAB_URL`/users/auth/auth0/callback (or)
+    - https://`YOUR_GITLAB_URL`/users/auth/auth0/callback
+
+1. Fill in the Allowed Origins (CORS):
+    - http://`YOUR_GITLAB_URL` (or)
+    - https://`YOUR_GITLAB_URL`
+
+1. On your GitLab server, open the configuration file.
+
+    For omnibus package:
+
+    ```sh
+      sudo editor /etc/gitlab/gitlab.rb
+    ```
+
+    For installations from source:
+
+    ```sh
+      cd /home/git/gitlab
+      sudo -u git -H editor config/gitlab.yml
+    ```
+
+1. See [Initial OmniAuth Configuration](omniauth.md#initial-omniauth-configuration)
+for initial settings.
+
+1. Add the provider configuration:
+
+    For omnibus package:
+
+    ```ruby
+      gitlab_rails['omniauth_providers'] = [
+        {
+          "name" => "auth0",
+          "args" => { client_id: 'YOUR_AUTH0_CLIENT_ID'',
+                      client_secret: 'YOUR_AUTH0_CLIENT_SECRET',
+                      namespace: 'YOUR_AUTH0_DOMAIN'
+                    }
+        }
+      ]
+    ```
+
+    For installations from source:
+
+    ```yaml
+      - { name: 'auth0',
+          args: {
+            client_id: 'YOUR_AUTH0_CLIENT_ID',
+            client_secret: 'YOUR_AUTH0_CLIENT_SECRET',
+            namespace: 'YOUR_AUTH0_DOMAIN'
+            }
+        }
+    ```
+
+1. Change `YOUR_AUTH0_CLIENT_ID` to the client ID from the Auth0 Console page
+from step 5.
+
+1. Change `YOUR_AUTH0_CLIENT_SECRET` to the client secret from the Auth0 Console
+page from step 5.
+
+1. Save the file and [reconfigure GitLab](../administration/restart_gitlab.md)
+for the changes to take effect.
+
+On the sign in page there should now be an Auth0 icon below the regular sign in
+form. Click the icon to begin the authentication process. Auth0 will ask the
+user to sign in and authorize the GitLab application. If everything goes well
+the user will be returned to GitLab and will be signed in.

doc/integration/omniauth.md

@@ -28,6 +28,7 @@ contains some settings that are common for all providers.
 - [SAML](saml.md)
 - [Crowd](crowd.md)
 - [Azure](azure.md)
+- [Auth0](auth0.md)
 
 ## Initial OmniAuth Configuration