I found a topic one years ago, it is not possible at that time. Can we do it now with filebeat 5.5.1? I want some part of the message to be the key of the kafka message. For example, the log message is like:
2017:07:21 ip:18.104.22.168 xxxxxxxxxxxxxxxxx
I want to set a regular expression to extract the ip as the kafka message key. Is it possible with the latest filebeat?