Add more instance stats APIs (#6125)

* Add GET /api/v1/instance/peers API to reveal known domains

* Add GET /api/v1/instance/activity API

* Make new APIs disableable, exclude private statuses from activity stats

* Fix code style issue

* Fix week timestamps

config/locales/en.yml

@@ -265,12 +265,18 @@ en:
       unresolved: Unresolved
       view: View
     settings:
+      activity_api_enabled:
+        desc_html: Counts of locally posted statuses, active users, and new registrations in weekly buckets
+        title: Publish aggregate statistics about user activity
       bootstrap_timeline_accounts:
         desc_html: Separate multiple usernames by comma. Only local and unlocked accounts will work. Default when empty is all local admins.
         title: Default follows for new users
       contact_information:
         email: Business e-mail
         username: Contact username
+      peers_api_enabled:
+        desc_html: Domain names this instance has encountered in the fediverse
+        title: Publish list of discovered instances
       registrations:
         closed_message:
           desc_html: Displayed on frontpage when registrations are closed. You can use HTML tags

config/routes.rb

@@ -241,7 +241,11 @@ Rails.application.routes.draw do
 
       resources :apps, only: [:create]
 
-      resource :instance,      only: [:show]
+      resource :instance, only: [:show] do
+        resources :peers, only: [:index], controller: 'instances/peers'
+        resource :activity, only: [:show], controller: 'instances/activity'
+      end
+
       resource :domain_blocks, only: [:show, :create, :destroy]
 
       resources :follow_requests, only: [:index] do

config/settings.yml

@@ -47,7 +47,8 @@ defaults: &defaults
     - webmaster
     - administrator
   bootstrap_timeline_accounts: ''
-
+  activity_api_enabled: true
+  peers_api_enabled: true
 development:
   <<: *defaults