Application Statistics API

This change implements Application
Statistics API

lib/api/api.rb

@@ -161,6 +161,7 @@ module API
     mount ::API::Settings
     mount ::API::SidekiqMetrics
     mount ::API::Snippets
+    mount ::API::Statistics
     mount ::API::Submodules
     mount ::API::Subscriptions
     mount ::API::Suggestions

lib/api/entities.rb

@@ -1167,6 +1167,55 @@ module API
       expose :message, :starts_at, :ends_at, :color, :font
     end
 
+    class ApplicationStatistics < Grape::Entity
+      include ActionView::Helpers::NumberHelper
+      include CountHelper
+
+      expose :forks do |counts|
+        approximate_fork_count_with_delimiters(counts)
+      end
+
+      expose :issues do |counts|
+        approximate_count_with_delimiters(counts, ::Issue)
+      end
+
+      expose :merge_requests do |counts|
+        approximate_count_with_delimiters(counts, ::MergeRequest)
+      end
+
+      expose :notes do |counts|
+        approximate_count_with_delimiters(counts, ::Note)
+      end
+
+      expose :snippets do |counts|
+        approximate_count_with_delimiters(counts, ::Snippet)
+      end
+
+      expose :ssh_keys do |counts|
+        approximate_count_with_delimiters(counts, ::Key)
+      end
+
+      expose :milestones do |counts|
+        approximate_count_with_delimiters(counts, ::Milestone)
+      end
+
+      expose :users do |counts|
+        approximate_count_with_delimiters(counts, ::User)
+      end
+
+      expose :projects do |counts|
+        approximate_count_with_delimiters(counts, ::Project)
+      end
+
+      expose :groups do |counts|
+        approximate_count_with_delimiters(counts, ::Group)
+      end
+
+      expose :active_users do |_|
+        number_with_delimiter(::User.active.count)
+      end
+    end
+
     class ApplicationSetting < Grape::Entity
       def self.exposed_attributes
         attributes = ::ApplicationSettingsHelper.visible_attributes

lib/api/statistics.rb

+# frozen_string_literal: true
+
+module API
+  class Statistics < Grape::API
+    before { authenticated_as_admin! }
+
+    COUNTED_ITEMS = [Project, User, Group, ForkNetworkMember, ForkNetwork, Issue,
+                     MergeRequest, Note, Snippet, Key, Milestone].freeze
+
+    desc 'Get the current application statistics' do
+      success Entities::ApplicationStatistics
+    end
+    get "application/statistics" do
+      counts = Gitlab::Database::Count.approximate_counts(COUNTED_ITEMS)
+      present counts, with: Entities::ApplicationStatistics
+    end
+  end
+end