bbende commented on a change in pull request #4852: URL: https://github.com/apache/nifi/pull/4852#discussion_r583882100
########## File path: nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-framework-core/src/main/java/org/apache/nifi/controller/ExtensionBuilder.java ########## @@ -463,10 +524,12 @@ private ControllerServiceNode createGhostControllerServiceNode() { Thread.currentThread().setContextClassLoader(detectedClassLoader); final Object extensionInstance = rawClass.newInstance(); + final T cast = nodeType.cast(extensionInstance); + verifyControllerServiceReferences(cast, bundle.getClassLoader()); Review comment: When testing creating some processors I decided to try adding PutHDFS since it has `@RequiresInstanceClassLoading`, and it produced a ghost component with this exception in the logs... ``` Caused by: java.lang.NullPointerException: null at java.util.ArrayList.<init>(ArrayList.java:178) at org.apache.nifi.processors.hadoop.PutHDFS.getSupportedPropertyDescriptors(PutHDFS.java:202) at org.apache.nifi.components.AbstractConfigurableComponent.getPropertyDescriptors(AbstractConfigurableComponent.java:247) at org.apache.nifi.controller.ExtensionBuilder.verifyControllerServiceReferences(ExtensionBuilder.java:433) at org.apache.nifi.controller.ExtensionBuilder.createLoggableComponent(ExtensionBuilder.java:528) at org.apache.nifi.controller.ExtensionBuilder.createLoggableProcessor(ExtensionBuilder.java:485) ... 170 common frames omitted ``` I think the issue is that verify is calls `getSupportedPropertyDescritptors`, but we haven't called `initialize` on the component yet and we don't know if initialize is what sets up the component's property descriptors. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org