I wanted to use filebeat for sending log message as it is to Kafka. We are doing the log enrichment from our service and we don't really need the beats provided one. I found a bit tricky to achieve this so I added this feature to the kafka output. -> https://github.com/elastic/beats/pull/1921
With this change you can add the following parameter to kafka output to specify which field you want to send:
In this case it will only send the message field of the message and ignore every other field.
What do you think? Is it useful for you as well?