Enforces terms in the web application

This enforces the terms in the web application. These cases are
specced:

- Logging in: When terms are enforced, and a user logs in that has not
  accepted the terms, they are presented with the screen. They get
  directed to their customized root path afterwards.
- Signing up: After signing up, the first screen the user is presented
  with the screen to accept the terms. After they accept they are
  directed to the dashboard.
- While a session is active:
  - For a GET: The user will be directed to the terms page first,
    after they accept the terms, they will be directed to the page
    they were going to
  - For any other request: They are directed to the terms, after they
    accept the terms, they are directed back to the page they came
    from to retry the request. Any information entered would be
    persisted in localstorage and available on the page.

4 files changed, 39 insertions, 0 deletions

diff --git a/doc/administration/index.md b/doc/administration/index.md
index b472ca5b4d8..5551a04959c 100644
--- a/doc/administration/index.md
+++ b/doc/administration/index.md
@@ -40,6 +40,7 @@ Learn how to install, configure, update, and maintain your GitLab instance.
 [source installations](../install/installation.md#installation-from-source).
 - [Environment variables](environment_variables.md): Supported environment variables that can be used to override their defaults values in order to configure GitLab.
 - [Plugins](plugins.md): With custom plugins, GitLab administrators can introduce custom integrations without modifying GitLab's source code.
+- [Enforcing Terms of Service](../user/admin_area/settings/terms.md)
 
 #### Customizing GitLab's appearance
 
diff --git a/doc/user/admin_area/settings/img/enforce_terms.png b/doc/user/admin_area/settings/img/enforce_terms.png
new file mode 100755
index 00000000000..e5f0a2683b5
--- /dev/null
+++ b/doc/user/admin_area/settings/img/enforce_terms.png
diff --git a/doc/user/admin_area/settings/img/respond_to_terms.png b/doc/user/admin_area/settings/img/respond_to_terms.png
new file mode 100755
index 00000000000..d0d086c3498
--- /dev/null
+++ b/doc/user/admin_area/settings/img/respond_to_terms.png
diff --git a/doc/user/admin_area/settings/terms.md b/doc/user/admin_area/settings/terms.md
new file mode 100644
index 00000000000..8e1fb982aba
--- /dev/null
+++ b/doc/user/admin_area/settings/terms.md
@@ -0,0 +1,38 @@
+# Enforce accepting Terms of Service
+
+> [Introduced](https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/18570)
+> in [GitLab Core](https://about.gitlab.com/pricing/) 10.8
+
+## Configuration
+
+When it is required for all users of the GitLab instance to accept the
+Terms of Service, this can be configured by an admin on the settings
+page:
+
+![Enable enforcing Terms of Service](img/enforce_terms.png).
+
+The terms itself can be entered using Markdown. For each update to the
+terms, a new version is stored. When a user accepts or declines the
+terms, GitLab will keep track of which version they accepted or
+declined.
+
+When an admin enables this feature, they will automattically be
+directed to the page to accept the terms themselves. After they
+accept, they will be directed back to the settings page.
+
+## Accepting terms
+
+When this feature was enabled, the users that have not accepted the
+terms of service will be presented with a screen where they can either
+accept or decline the terms.
+
+![Respond to terms](img/respond_to_terms.png)
+
+When the user accepts the terms, they will be directed to where they
+were going. After a sign-in or sign-up this will most likely be the
+dashboard.
+
+When the user was already logged in when the feature was turned on,
+they will be asked to accept the terms on their next interaction.
+
+When a user declines the terms, they will be signed out.