title: Provide backend server in url variable?
body: <p>I would like to check if its possible in HA Proxy setup the &quot;server&quot; dinamically. Lets sa I have something like this:</p>
  <pre><code>global
  
  defaults
      timeout client  30s
      timeout connect 30s
      timeout server  30s
  
  frontend https-in
      bind    *:443 ssl crt /etc/ssl/private/cert.pem
      use_backend redirect if { ssl_fc_sni server.test } { path_beg /redirect }
  
  backend redirect
      use-server some_target_server.test if { urlp(host) -i some_target_server.test }
      
      server some_target_server.test some_target_server.test:443 check check-ssl verify none ssl sni req.hdr(host) check-sni some_target_server.test
  </code></pre>
  <p>Is is possible the value &quot;some_target_server.test&quot; be given to ha proxy, maybe in parameter or something... reason is that redirection in my case is not solid list of server, but it changes and I can provide in url to what server I want to redirect ( thats a known value)</p>