I want to use ``logstash`` to parse and collect mongodb logs.

But I think it's hard to use ``grok`` regex pattern to parse the logs.

Is there any way to let mongodb output logs as json? Or other better grok pattern? The logstash built-in mongodb grok pattern does not match all logs(https://github.com/logstash-plugins/logstash-patterns-core/blob/master/patterns/mongodb).