feat: add support for custom headers

[AndreasPB]

• Adds support for adding custom headers to the collector

Example:

go run apache_exporter.go --custom_headers=Cookie=do_something=1 --custom_headers=Cookie=something_else

This is something we use at work and wanted to share :)

#71

[AndreasPB]

I forgot to run go fmt 🙈 - It should pass CI now, @Lusitaniae

[Lusitaniae]

thanks, looks good!

[dswarbrick]

Reading the original motivation for this (#71), it seems like adding a an Accept header should just be something that any well-written application should do.

The User-Agent header is something that blackbox_exporter recently added, and I agree this makes it a lot nicer when trying to filter out monitoring requests from access logs.

But beyond those, what other custom headers are really needed? Authentication?

[AndreasPB]

But beyond those, what other custom headers are really needed? Authentication?

We have been using it to set a Cookie that controls how Apache looks at the login sessions

[AndreasPB]

Should I make some changes, or what is the status of this? @Lusitaniae

I could add the accept header (defaulting to */*?) as a separate command (maybe in a different PR).

[blkperl]

Looks good to me!

[AndreasPB]

Do I need to do something?

[Lusitaniae]

No need, many thanks

Merged and released in https://github.com/Lusitaniae/apache_exporter/releases/tag/v1.0.0

if you'd like to test

[AndreasPB]

Perfect, thank you :)