overwrite_keys fix for #6381

[ewgRa]

Explanations of bug in original issue #6381

[elasticmachine]

Since this is a community submitted pull request, a Jenkins build has not been kicked off automatically. Can an Elastic organization member please verify the contents of this patch and then kick off a build manually?

[urso]

Looks good.

Only Event.Meta must be allowed to be nil. If meta is not used by a beat, we should not allocate memory for it.

Not sure we really want to read @metadata fields from inputs json. The @metadata field is somewhat special, as it can be used to control some behavior in the output in beats + control event routing in Logstash.

[Zenexer]

@urso I'm encountering #6381 while attempting to overwrite @metadata. Use case: I want to put data into @metadata that's eventually used to set outputs.elasticsearch.document_id in Logstash.

[kaiyan-sheng]

Hi @ewgRa, seems like there is no update on this PR for a long time. I will close this PR for now and please feel free to open a new PR or reopen this one in the future.