iRule for App Offline

Hi,

I use following irule to manage maintenance page per pool.

with this rule, pool can be assigned by a irule executed before or by an LTM Policy.

when HTTP_REQUEST {
    switch [HTTP::path] {
        "/maintenance/logo.png" {
            HTTP::respond 200 content [ifile get "logo.png"] "Content-Type" "image/png"
            return
        }
        "/maintenance/maintenance.html" {
            HTTP::respond 200 content [ifile get "maintenance.html"] "Content-Type" "text/html"
            return
        }
        "/maintenance/error.html" {
            HTTP::respond 200 content [ifile get "error.html"] "Content-Type" "text/html"
            return
        }
        default {
            set dpool [LB::server pool]
            if { $dpool equals "" } { HTTP::redirect "/maintenance/error.html" ; unset dpool; return}
            if { [active_members $dpool] == 0 } { HTTP::redirect "/maintenance/maintenance.html"; unset dpool; return}
            unset dpool
        }
    }
}

when HTTP_RESPONSE {
  if { [HTTP::status] eq "404" } { HTTP::redirect "/maintenance/error.html" }
}