Rename host logging field

Rename the "host" logging field to "request_host". An additional
"host" field is added to the logs that go to Splunk for Kenesis. This
means we end up with 2 values for "host" making it difficult to filter
searches by it.

Author: stephencdaly

app/controllers/application_controller.rb

@@ -37,7 +37,7 @@ def check_maintenance_mode_is_enabled
   end
 
   def set_logging_attributes
-    CurrentLoggingAttributes.host = request.host
+    CurrentLoggingAttributes.request_host = request.host
     CurrentLoggingAttributes.request_id = request.request_id
     CurrentLoggingAttributes.session_id_hash = Digest::SHA256.hexdigest session.id.to_s if session.exists? && session.id.present?
     CurrentLoggingAttributes.trace_id = request.env["HTTP_X_AMZN_TRACE_ID"].presence

app/models/current_logging_attributes.rb

@@ -1,5 +1,5 @@
 class CurrentLoggingAttributes < ActiveSupport::CurrentAttributes
-  attribute :host, :request_id, :session_id_hash, :trace_id, :user_ip,
+  attribute :request_host, :request_id, :session_id_hash, :trace_id, :user_ip,
             :user_id, :user_email, :user_organisation_slug, :acting_as_user_id,
             :acting_as_user_email, :acting_as_user_organisation_slug, :form_id,
             :page_id

spec/requests/application_controller_spec.rb

@@ -34,8 +34,8 @@
       expect(log_lines[0]["request_id"]).to eq(request_id)
     end
 
-    it "includes the host on log lines" do
-      expect(log_lines[0]["host"]).to eq("www.example.com")
+    it "includes the request_host on log lines" do
+      expect(log_lines[0]["request_host"]).to eq("www.example.com")
     end
 
     it "includes the user_id on log lines" do