Setting a unique header per server in a backend

[Sachin Shetty]

Hi,

We have a tricky requirement to set a different header value in the request
based on which server in a backend is picked.

backend pod0
    ...
    server server1 server1:6180  check
    server server2 server2:6180  check
    server server3 server3:6180  check

so when request is forwarded to server1 - I want to inject an header
"X-Some-Header: Server1",  "X-Some-Header: Server2"  for server 2 and so
on.

If it possible to register some lua action that would inject the header
based on the server selected  before the request is forwarded to the server.

Thanks
Sachin