Return error in broker_controller.exec() if remote command is failed.
Check if broker_controller.exec() returns error. If so, operator would NOT generating command to write the remote command results into specified files, which will write <nil> into subscriptionGroup.json or topics.json and cause startup failure of broker.
Try to fix #80 :
broker_controller.exec()
if remote command is failed.broker_controller.exec()
returns error. If so, operator would NOT generating command to write the remote command results into specified files, which will write<nil>
intosubscriptionGroup.json
ortopics.json
and cause startup failure of broker.