Rewrite the "Location" header on redirect responses, replacing all host matches with the public address about teleport

[webvictim]

#34705 would probably allow this, but hasn't moved forward for a while.

[BulatSaif]

#34705 would probably allow this, but hasn't moved forward for a while.

PR #34705 is certainly useful, and I would appreciate having options to modify the body in future updates. However, it does not address my current issue with headers. To address this, I've created a small Proof of Concept (PoC) GitHub PR #43300. The idea behind this PoC is to replace all occurrences of hosts in the "Location" header.

[BulatSaif]

I updated my GitHub PR #43300 and added an alternative rewrite redirectRegex. It's designed to be more powerful and readable. Below are two configurations that achieve the same replacement:

Configuration 1:

apps:
  - name: "MyName"
    public_addr: "mydomain"
    rewrite:
      # Replace domain in Location header
      redirect:
      - "localhost"

Configuration 2:

apps:
  - name: "MyName"
    rewrite:
      # Replace Location header using regex
      redirectRegex:
        regex: ^http[s]?://localhost/(.*)
        replacement: http://mydomain/${1}

Here's a configuration that covers my use case, replacing all occurrences of localhost in the header:

apps:
  - name: "MyName"
    rewrite:
      # Replace Location header using regex
      redirectRegex:
        regex: localhost
        replacement: mydomain