Combining iRules for maintenance page with 503 code

root@(ve11a)(cfg-sync Changes Pending)(Active)(/Common)(tmos) list ltm virtual bar
ltm virtual bar {
    destination 172.28.20.14:80
    ip-protocol tcp
    mask 255.255.255.255
    pool foo
    profiles {
        http { }
        tcp { }
    }
    rules {
        myrule
    }
    source 0.0.0.0/0
    source-address-translation {
        type automap
    }
    vlans-disabled
}
root@(ve11a)(cfg-sync Changes Pending)(Active)(/Common)(tmos) list ltm pool foo
ltm pool foo {
    members {
        200.200.200.101:80 {
            address 200.200.200.101
            session monitor-enabled
            state down
        }
    }
    monitor fake
}

 Controlling Bots 
 https://devcentral.f5.com/wiki/iRules.ControllingBots.ashx

root@(ve11a)(cfg-sync Changes Pending)(Active)(/Common)(tmos) list ltm rule myrule
ltm rule myrule {
    when HTTP_REQUEST {
  if { [active_members [LB::server pool]] < 1 } {
    switch -glob [string tolower [HTTP::header User-Agent]] {
      "*scooter*" -
      "*slurp*" -
      "*msnbot*" -
      "*fast-*" -
      "*teoma*" -
      "*googlebot*" {
        HTTP::respond 503 content "" noserver
        return
      }
   }

    switch [HTTP::path] {
      "/f5.gif" { HTTP::respond 200 content [ifile get f5_gif_ifile] noserver }
      default {
        HTTP::respond 200 content [ifile get maint_html_ifile] noserver
      }
    }
  }
}
}

 maintenance page

[root@ve11a:Active:Changes Pending] config  curl -i http://172.28.20.14
HTTP/1.0 200 OK
Connection: Keep-Alive
Content-Length: 97




This is maintenance page.




 googlebot

[root@ve11a:Active:Changes Pending] config  curl -i http://172.28.20.14 -H "User-Agent: googlebot"
HTTP/1.0 503 Service Unavailable
Connection: Keep-Alive
Content-Length: 0

 normal page

root@(ve11a)(cfg-sync Changes Pending)(Active)(/Common)(tmos) modify ltm pool foo monitor none
root@(ve11a)(cfg-sync Changes Pending)(Active)(/Common)(tmos) list ltm pool foo
ltm pool foo {
    members {
        200.200.200.101:80 {
            address 200.200.200.101
        }
    }
}

[root@ve11a:Active:Changes Pending] config  curl -i http://172.28.20.14
HTTP/1.1 200 OK
Date: Wed, 16 Jan 2013 07:39:16 GMT
Server: Apache/2.2.3 (CentOS)
Last-Modified: Sat, 27 Oct 2012 03:22:35 GMT
ETag: "4183f3-59-f28f94c0"
Accept-Ranges: bytes
Content-Length: 89
Content-Type: text/html; charset=UTF-8




This is 101 host.