Backport CE to changes to support group-level file templates

When the feature is available, this setting allows admins to choose a
project as a source of custom file templates. This is in addition to
any instance-wide templates, whether custom or vendored into the GitLab
codebase.

app/assets/javascripts/pages/groups/edit/index.js

@@ -5,6 +5,7 @@ import initSettingsPanels from '~/settings_panels';
 import dirtySubmitFactory from '~/dirty_submit/dirty_submit_factory';
 import mountBadgeSettings from '~/pages/shared/mount_badge_settings';
 import { GROUP_BADGE } from '~/badges/constants';
+import projectSelect from '~/project_select';
 
 document.addEventListener('DOMContentLoaded', () => {
   groupAvatar();
@@ -15,4 +16,6 @@ document.addEventListener('DOMContentLoaded', () => {
     document.querySelectorAll('.js-general-settings-form, .js-general-permissions-form'),
   );
   mountBadgeSettings(GROUP_BADGE);
+
+  projectSelect();
 });

app/views/groups/edit.html.haml

@@ -37,6 +37,8 @@
   .settings-content
     = render 'shared/badges/badge_settings'
 
+= render_if_exists 'groups/templates_setting', expanded: expanded
+
 %section.settings.gs-advanced.no-animate#js-advanced-settings{ class: ('expanded' if expanded) }
   .settings-header
     %h4.settings-title.js-settings-toggle.js-settings-toggle-trigger-only{ role: 'button' }

doc/api/groups.md

@@ -37,6 +37,7 @@ GET /groups
     "request_access_enabled": false,
     "full_name": "Foobar Group",
     "full_path": "foo-bar",
+    "file_template_project_id": 1,
     "parent_id": null
   }
 ]
@@ -62,6 +63,7 @@ GET /groups?statistics=true
     "request_access_enabled": false,
     "full_name": "Foobar Group",
     "full_path": "foo-bar",
+    "file_template_project_id": 1,
     "parent_id": null,
     "statistics": {
       "storage_size" : 212,
@@ -122,6 +124,7 @@ GET /groups/:id/subgroups
     "request_access_enabled": false,
     "full_name": "Foobar Group",
     "full_path": "foo-bar",
+    "file_template_project_id": 1,
     "parent_id": 123
   }
 ]
@@ -232,6 +235,7 @@ Example response:
   "request_access_enabled": false,
   "full_name": "Twitter",
   "full_path": "twitter",
+  "file_template_project_id": 1,
   "parent_id": null,
   "projects": [
     {
@@ -386,6 +390,7 @@ Example response:
   "request_access_enabled": false,
   "full_name": "Twitter",
   "full_path": "twitter",
+  "file_template_project_id": 1,
   "parent_id": null
 }
 ```
@@ -442,6 +447,7 @@ PUT /groups/:id
 | `visibility` | string | no | The visibility level of the group. Can be `private`, `internal`, or `public`. |
 | `lfs_enabled` (optional) | boolean | no | Enable/disable Large File Storage (LFS) for the projects in this group |
 | `request_access_enabled` | boolean | no | Allow users to request member access. |
+| `file_template_project_id` | integer | no | **(Premium)** The ID of a project to load custom file templates from |
 
 ```bash
 curl --request PUT --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" "https://gitlab.example.com/api/v4/groups/5?name=Experimental"
@@ -462,6 +468,7 @@ Example response:
   "request_access_enabled": false,
   "full_name": "Foobar Group",
   "full_path": "foo-bar",
+  "file_template_project_id": 1,
   "parent_id": null,
   "projects": [
     {

doc/api/project_templates.md

 # Project templates API
 
-This API is a project-specific implementation of these endpoints:
+This API is a project-specific version of these endpoints:
 
 - [Dockerfile templates](templates/dockerfiles.md)
 - [Gitignore templates](templates/gitignores.md)
 - [GitLab CI Config templates](templates/gitlab_ci_ymls.md)
 - [Open source license templates](templates/licenses.md)
 
-It deprecates those endpoints, which will be removed for API version 5.
+It deprecates these endpoints, which will be removed for API version 5.
 
-Project-specific templates will be added to this API in time. This includes, but
-is not limited to:
+In addition to templates common to the entire instance, project-specific
+templates are also available from this API endpoint.
 
-- [Issue and Merge Request templates](../user/project/description_templates.html)
-- [Group level file templates](https://gitlab.com/gitlab-org/gitlab-ee/issues/5987) **(Premium)**
+Support will be added for [Issue and Merge Request templates](../user/project/description_templates.md)
+in a future release.
+
+Support for [Group-level file templates](../user/group/index.md#group-level-file-templates-premium)
+**[PREMIUM]** was [added](https://gitlab.com/gitlab-org/gitlab-ee/issues/5987)
+in GitLab 11.5
 
 ## Get all templates of a particular type
 

doc/user/group/index.md

@@ -252,6 +252,13 @@ level of members in group.
 
 Learn more about [Member Lock](https://docs.gitlab.com/ee/user/group/index.html#member-lock).
 
+#### Group-level file templates **[PREMIUM]**
+
+Group-level file templates allow you to share a set of templates for common file
+types with every project in a group.
+
+Learn more about [Group-level file templates](https://docs.gitlab.com/ee/user/group/index.html#group-level-file-templates-premium).
+
 ### Advanced settings
 
 - **Projects**: view all projects within that group, add members to each project,

lib/gitlab/template/base_template.rb

 module Gitlab
   module Template
     class BaseTemplate
-      attr_reader :category
+      attr_accessor :category
 
       def initialize(path, project = nil, category: nil)
         @path = path