Add instance statistics settings to API

doc/api/settings.md

@@ -55,7 +55,8 @@ Example response:
    "ed25519_key_restriction": 0,
    "enforce_terms": true,
    "terms": "Hello world!",
-   "performance_bar_allowed_group_id": 42
+   "performance_bar_allowed_group_id": 42,
+   "instance_statistics_visibility_private": false
 }
 ```
@@ -159,6 +160,7 @@ PUT /application/settings
 | `version_check_enabled`                  | boolean          | no                                            | Let GitLab inform you when an update is available.                                                                                                                                                                                                                                                                                                                                                                                                        |
 | `enforce_terms`                          | boolean          | no                                            | Enforce application ToS to all users                                                                                                                                                                                                                                                                                                                                                                                                         |
 | `terms`                                  | text             | yes (if `enforce_terms` is true)              | Markdown content for the ToS                                                                                                                                                                                                                                                                                                                                                                                                                 |
+| `instance_statistics_visibility_private` | boolean          | no                                            | When set to `true` Instance statistics will only be available to admins                                                                                                                                                                                                                                                                                                                                                                      |
 ```bash
 curl --request PUT --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" https://gitlab.example.com/api/v4/application/settings?signup_enabled=false&default_project_visibility=internal
@@ -203,6 +205,7 @@ Example response:
   "ed25519_key_restriction": 0,
   "enforce_terms": true,
   "terms": "Hello world!",
-  "performance_bar_allowed_group_id": 42
+  "performance_bar_allowed_group_id": 42,
+  "instance_statistics_visibility_private": false
 }
 ```

lib/api/settings.rb

@@ -130,6 +130,7 @@ module API
       optional :gitaly_timeout_medium, type: Integer, desc: 'Medium Gitaly timeout, in seconds. Set to 0 to disable timeouts.'
       optional :gitaly_timeout_fast, type: Integer, desc: 'Gitaly fast operation timeout, in seconds. Set to 0 to disable timeouts.'
       optional :usage_ping_enabled, type: Boolean, desc: 'Every week GitLab will report license usage back to GitLab, Inc.'
+      optional :instance_statistics_visibility_private, type: Boolean, desc: 'When set to `true` Instance statistics will only be available to admins'
       ApplicationSetting::SUPPORTED_KEY_TYPES.each do |type|
         optional :"#{type}_key_restriction",

spec/requests/api/settings_spec.rb

@@ -25,6 +25,7 @@ describe API::Settings, 'Settings' do
       expect(json_response['ed25519_key_restriction']).to eq(0)
       expect(json_response['circuitbreaker_failure_count_threshold']).not_to be_nil
       expect(json_response['performance_bar_allowed_group_id']).to be_nil
+      expect(json_response['instance_statistics_visibility_private']).to be(false)
       expect(json_response).not_to have_key('performance_bar_allowed_group_path')
       expect(json_response).not_to have_key('performance_bar_enabled')
     end
@@ -64,7 +65,8 @@ describe API::Settings, 'Settings' do
           circuitbreaker_check_interval: 2,
           enforce_terms: true,
           terms: 'Hello world!',
-          performance_bar_allowed_group_path: group.full_path
+          performance_bar_allowed_group_path: group.full_path,
+          instance_statistics_visibility_private: true
         expect(response).to have_gitlab_http_status(200)
         expect(json_response['default_projects_limit']).to eq(3)
@@ -89,6 +91,7 @@ describe API::Settings, 'Settings' do
         expect(json_response['enforce_terms']).to be(true)
         expect(json_response['terms']).to eq('Hello world!')
         expect(json_response['performance_bar_allowed_group_id']).to eq(group.id)
+        expect(json_response['instance_statistics_visibility_private']).to be(true)
       end
     end