Gab Social. All are welcome.

app/controllers/well_known/webfinger_controller.rb

@@ -0,0 +1,44 @@
+# frozen_string_literal: true
+
+module WellKnown
+  class WebfingerController < ActionController::Base
+    include RoutingHelper
+
+    before_action { response.headers['Vary'] = 'Accept' }
+
+    def show
+      @account = Account.find_local!(username_from_resource)
+
+      respond_to do |format|
+        format.any(:json, :html) do
+          render json: @account, serializer: WebfingerSerializer, content_type: 'application/jrd+json'
+        end
+
+        format.xml do
+          render content_type: 'application/xrd+xml'
+        end
+      end
+
+      expires_in(3.days, public: true)
+    rescue ActiveRecord::RecordNotFound
+      head 404
+    end
+
+    private
+
+    def username_from_resource
+      resource_user = resource_param
+
+      username, domain = resource_user.split('@')
+      if Rails.configuration.x.alternate_domains.include?(domain)
+        resource_user = "#{username}@#{Rails.configuration.x.local_domain}"
+      end
+
+      WebfingerResource.new(resource_user).username
+    end
+
+    def resource_param
+      params.require(:resource)
+    end
+  end
+end