Added allow legacy flag to expose montoring section in API

Author: andsel

logstash-core/lib/logstash/api/commands/default_metadata.rb

@@ -71,6 +71,7 @@ def http_address
 
         private
         def enabled_xpack_monitoring?
+          LogStash::SETTINGS.get_value("allow.legacy.monitoring") &&
           LogStash::SETTINGS.registered?("xpack.monitoring.enabled") &&
           LogStash::SETTINGS.get("xpack.monitoring.enabled")
         end

logstash-core/spec/logstash/api/commands/default_metadata_spec.rb

@@ -54,13 +54,22 @@ def registerIfNot(setting)
         )
     end
 
-    it "check monitoring exist when monitoring is enabled" do
+    it "check monitoring section exist when legacy monitoring is enabled and allowed" do
+      LogStash::SETTINGS.set_value("allow.legacy.monitoring", true)
       LogStash::SETTINGS.set_value("xpack.monitoring.enabled", true)
       expect(report.keys).to include(
         :monitoring
         )
     end
 
+    it "check monitoring section does not appear when legacy monitoring is not allowed but enabled" do
+      LogStash::SETTINGS.set_value("allow.legacy.monitoring", false)
+      LogStash::SETTINGS.set_value("xpack.monitoring.enabled", true)
+      expect(report.keys).not_to include(
+                               :monitoring
+                             )
+    end
+
     it "check monitoring does not appear when not enabled and nor cluster_uuid is defined" do
       LogStash::SETTINGS.set_value("xpack.monitoring.enabled", false)
       LogStash::SETTINGS.get_setting("monitoring.cluster_uuid").reset