Multi site redirect using host headers

Hi Rwagner,

security wise its always a good idea to use a white-list of acceptable values before passing user provided information to subsequent iRule commands. Depending on you remaining configuration you original iRule may allow the user to select a pool which was not intended...

You may check to the iRule below. It will white-list the individual [HTTP::host] values and assign a pool or perform a 301 - Permanent Redirect as needed and last but not least send a 503 - Bad Gateway response for every request with an unknown [HTTP::host] value.

After assigning the [pool], the iRule checks if the currently selected pool object has [active_members] available . If not the iRule would respond with your Maintenance-Page using a 502 - Service Unavailable response code to not hurt your Google search results and SEO ratings...

when HTTP_REQUEST { 
    switch -exact -- [string tolower [HTTP::host] {
        "www.abc.com" {
            pool "www.abc.com"
        }
        "www.xyz.com" {
            pool "www.xyz.com"
        }
        "abc.com" {
            HTTP::respond 301 "Location" "//www.abc.com[HTTP::uri]"
            return
        }
        "xyz.com" {
            HTTP::respond 301 "Location" "//www.abc.com[HTTP::uri]"
            return
        }
        default {
            HTTP::respond 503 content "Bad Gateway" "Content-Type" "text/plain" 
            return
        }       
    }
    if { [active_members [LB::server pool]] < 1 } then {
        log local0.alert "ALERT-TEAM Pool \"[LB::server pool]\" is down. This mean \"[HTTP::host]\" website is down."; 
        HTTP::respond 502 content [ifile get App_Offline] 
    }
}

Cheers, Kai