Serving wpad.dat with F5?

9 years later...

I'm testing the LTM to server wpad/pac with irules and came up with this little script based on the response in this thread.

when HTTP_REQUEST {
    switch [string tolower [HTTP::host]] {
        "wpadtest.local" -
        "wpad.local" {
            set exp "function FindProxyForURL(url, host) {"
            append exp "\n" "if(isPlainHostName(host)) return \"DIRECT\";"
            append exp "\n" "if(shExpMatch(host, \"*\[^0123456789.\]*\") == false) return \"DIRECT\";"
            append exp "\n" "if(isInNet(host, \"127.0.0.0\", \"255.0.0.0\")) return \"DIRECT\";"
            append exp "\n" "if(isInNet(host, \"10.0.0.0\", \"255.0.0.0\")) return \"DIRECT\";"
            append exp "\n" "if(isInNet(host, \"172.16.0.0\", \"255.240.0.0\")) return \"DIRECT\";"
            append exp "\n" "if(isInNet(host, \"192.168.0.0\", \"255.255.0.0\")) return \"DIRECT\";"
            foreach mm [class names dg_wpad_shExpMatch] {
                append exp "" "if(shExpMatch(host, \"$mm\")) return \"DIRECT\";"
            }
             Last line
            append exp "\n" "return \"PROXY proxy.local:80\";\n}"
            HTTP::respond 200 content $exp "Content-Type" "application/x-ns-proxy-autoconfig"
        }
        default {
            HTTP::redirect https://[getfield [HTTP::host] ":" 1][HTTP::uri]
        }
    }
}

The data group list dg_wpad_shExpMatch contains all the exceptions where the client must bypass the proxy.

In a production environment this will be used by at least 1000-2000 users daily. Is there any way I can cache the output and set a 600 seconds TTL on the contents? Is this a good way of doing it or should I find other ways of serving this script?