iRule to resolve DNS for GTM (wide-ip if possible)

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1

Hi

I’ve server on cloud and want to try to use irule to resolve dynamic IP from cloud and return IP to user.

I saw irule LTM can use RESOLVE:lookup and we can use it on Listener.

But Is it possible to have the same function irule in wide-ip ?

because if we attach irule on Listener, it will surely take more performance than wide-ip.

Flow is When user send dns request for wide-ip “A” → F5 resolve dynamic IP from cloud (it’s hostname will be like ABCDEFG.cloud-us.com)-> F5 return IP to user.

ps. due to some circumstance CNAME is not possible.

Thank you

2

FYI

This is irule that can include on Listener. (But not wide ip)

The irule resolve dynamic IP from AWS and return to user.

Cloud server is ABC.ap-southeast-1.elb.amazonaws.com
when DNS_REQUEST {
if {([string tolower [DNS::question name]] equals "ABC.com") && ([DNS::question type] equals "A")} {
    set aws [RESOLV::lookup @8.8.8.8 -a "ABC.ap-southeast-1.elb.amazonaws.com"]
    DNS::answer insert "[DNS::question name]. 111 [DNS::question class] [DNS::question type] [lindex $aws 0]"
    DNS::return
    }
}