Is it possible to add custom Authentication headers to filebeat output being sent to logstash behind an nginx proxy?

Elastic Stack Beats
1

As the title says, in the Filebeat config file is it possible to define custom headers to be sent on output to Logstash?

the Filebeat documentation does not make it sound like thats an option that is available

https://www.elastic.co/guide/en/beats/libbeat/6.2/config-file-format.html

the idea stems from this post about Elasticsearch being able to live behind nginx
https://www.elastic.co/blog/playing-http-tricks-nginx

2

You can add HTTP headers to the Elasticsearch output. See output.elasticsearch.headers in the docs.

But the Logstash output is different because it uses a custom protocol sent over TCP. There's nowhere in the protocol to write the headers, and even it it did you would need a custom proxy that understood the protocol. I would use TLS mutual authentication to secure the traffic to Logstash.