Allow to collect HTTP Headers thanks to http_response

[essobedo]

Proposal:

The idea would be to have the ability to collect also HTTP Headers from the response thanks to the plugin http_response.

Current behavior:

So far, we only have access to very few headers which could be insufficient in particular use cases to properly treat the response since part of the data could be stored in the HTTP Headers of the response.

Desired behavior:

Provide the ability to configure a list of HTTP Headers to collect from the response. The value of those headers could be then stored as fields.

Use case:

I use the plugin http_response to access to different http endpoints which works pretty well but there are some endpoints that provide important information using custom HTTP headers that I cannot collect due to the current limitation, because of that, unless there is a workaround, I could have to use something else which I would like to avoid of course since I like Telegraf.

[essobedo]

A potential PR #7405

[essobedo]

@danielnelson Hi, could you please at least tell me if this feature request and the corresponding PR make sense to you or not? Thanks in advance