stream profile to match customer facing uris

OK, here's my first attempt. They may be a better way but for now I'm assuming the domain name ends with .com so we can match the start of each URI with .com/. If I just used / it will replace every / in the path and break things. Replace .com with whatever you use.

when HTTP_REQUEST {
 STREAM::disable
 log local0. "URI = [HTTP::uri]"
 switch [string tolower [HTTP::uri]] {
  "/devproxy/" {
   pool devproxy-pool
   set environuri /devproxy/
   return
    }
  "/qaproxy/" {
   pool qaproxy-pool
   set environuri /qaproxy/
   return
   }
  "/uatproxy/" {
   pool uatproxy-pool
   set environuri /uatproxy/
   return
   }
  default {
   HTTP::respond 200 content "Please use /devproxy to go to the dev-dmz-proxies,
   /qaproxy to go to the qa-dmz-proxies,
   /uatproxy to go to the uat-dmz-proxies" noserver Content-Type "text/html" Connection Close
}
}
}

when HTTP_RESPONSE {
 switch string $environuri {
  "/devproxy/" {
   STREAM::expression {@.com/@.com/devproxy/@}
   STREAM::enable
   return
    }
  "/qaproxy/" {
   STREAM::expression {@.com/@.com/qaproxy/@}
   STREAM::enable
   return
   }
  "/uatproxy/" {
   STREAM::expression {@.com/@.com/uatproxy/@}
   STREAM::enable
   return
   }
 }
}