Unable to set host header using standard HTTP options

[robcrawford]

Hello!

I'm using the prometheus metricbeat module and i'm trying to set the "Host" HTTP header for my target server. I'm using the standard http options to modify the headers.

Here's a snippet of my config:

- module: prometheus
  period: 10s
  hosts: ["http://metrics-host.example.com"]
  metrics_path: /metrics
  headers:
    Host: new-host.example.com
    X-Example-Header: test

My expected behaviour is that the "Host" header should be overridden, however that's not happening. The test header "X-Example-Header" works as expected.

Here's what the headers look like on the packet:

I'm using Metricbeat 7.4.2 (running via the official Docker image).

Is this behaviour expected or is it a bug in metricbeat? If it's the latter i'll open an issue on the project.

Thanks!!

[Kaiyan_Sheng]

Thanks for posting here. This seems to be a bug to me. Please open a github issue for this and we will triage it later. Thank you!