Feature: Add multiple configuration lines with 'BackendExtra'

[aisbergg]

It would be nice to add multiple lines to the backend with BackendExtra. Like other parameters the string should be separated with a comma.

[thomasjpfan]

Currently, BackendExtra does not support the comma to new-line notation. This may be because there are some haproxy options that use comma, such as resolve-opts: https://cbonte.github.io/haproxy-dconv/1.8/configuration.html#5.2-resolve-opts

[dimovnike]

This would be definitely great to have. I also need this option.

[chrsch]

I also would love to see this.

[thomasjpfan]

My only concern with adding this feature using comma as a separator is that it will break backwards compatibility. For example:

http-request set-header x-path %[hdr(x-path),regsub(/+,/,g)]

In this case, the comma needs to be there.

[chrsch]

I see. Two quick options then came to my mind earlier this day:

• Take an other delimiter (;; && ...) and implement a Split function (like described here: https://stackoverflow.com/questions/19771787/golang-how-to-split-string-in-template)
• Make an extra option BackendExtraMultiline which needs "," escaped if not used as a line delimiter

[thomasjpfan]

We could give the user complete control by adding BackendExtraMultilineSeparator.

[chrsch]

Oh yes I like this idea.

[vfarcic]

This project needs adoption. I moved to Kubernetes and cannot dedicate time to this project anymore. Similarly, involvement from other contributors dropped as well. Please consider contributing yourself if you think this project is useful.

[lle0x]

Dear @aisbergg

If this issue is still relevant, please feel free to leave a comment here.

[aisbergg]

I moved to Traefik