iRule for App Offline

when HTTP_REQUEST {

 set the host name and url to lower case
set Vuri [ string tolower [HTTP::uri]]
set Vheader [string tolower [HTTP::host]]

 set the Poolname variable.

set Poolname "pl_abc.123.com"
set poolname2 "pl_def.123.com"
set poolname3 "ghi.123.co"

 set the default site name variable

set SiteName "XXXX.MAINTENANCEPAGE.org"


set Irulename "Irule_$SiteName"
set SiteRedirect "https://$SiteName"
Obtain active poolmembers count and list
set Poolmember [active_members $Poolname ] 
set Poolmemberlist [ active_members -list $Poolname]

set Poolmember2 [active_members $Poolname2 ] 
set Poolmemberlist2 [ active_members -list $Poolname2]

set Poolmember3 [active_members $Poolname3 ] 
set Poolmemberlist3 [ active_members -list $Poolname3]


redirect to maintenance page if poolmembers count is zero

    switch $Vheader {

            abc.123.com {
                    if {$Poolmember < 1} then {
                        log local0.alert "ALERT-TEAM Pool $Poolname is down. This mean $SiteName website is down. IRULE=$Irulename";
                        HTTP::redirect "http://www.YOURPAGE-OFFLINE.COM"
                    } else {
                        pool $Poolname 
                    }  
            }
            def.123.com {
                    if {$Poolmember2 < 1} then {
                        log local0.alert "ALERT-TEAM Pool $Poolname is down. This mean $SiteName website is down. IRULE=$Irulename";
                        HTTP::redirect "http://www.YOURPAGE-OFFLINE.COM"
                    } else {
                        pool $Poolname2 
                    }  
            }

            ghi.123.com {
                    if {$Poolmember3 < 1} then {
                        log local0.alert "ALERT-TEAM Pool $Poolname is down. This mean $SiteName website is down. IRULE=$Irulename";
                        HTTP::redirect "http://www.YOURPAGE-OFFLINE.COM"
                    } else {
                        pool $Poolname3 
                    }  
            }

            default { HTTP::redirect "$SiteRedirect"}
    }   

}

  if the server sends a 500 error code log the error and redirect to maintenance page
when HTTP_RESPONSE {
    switch [HTTP::status] {
        500 {   log local0.alert "The servers is sending back a 500 Error: "
                HTTP::redirect "http://www.benaroyaresearch.org.s3-website-us-west-2.amazonaws.com/" 
            }
        502 { log local0.alert "The servers is sending back a 502 Error: "
                HTTP::redirect "http://www.benaroyaresearch.org.s3-website-us-west-2.amazonaws.com/"
            }
        503 {   log local0.alert "The servers is sending back a 503 Error: "
                HTTP::redirect "http://www.benaroyaresearch.org.s3-website-us-west-2.amazonaws.com/" 
            }
    }

}