https://devcentral.f5.com/questions/how-to-adjust-vip-setting-from-an-iapp-50787

_test.vip-tg

#TMSH-VERSION: 12.1.1

cli admin-partitions {
    update-partition Common
}
sys application template /Common/_test {
    actions {
        definition {
            html-help {
            }
            implementation {
                set static { ip-protocol tcp snat automap }
                set vip ${::vs__vip}

                iapp::conf create ltm virtual ${tmsh::app_name}_HTTP destination ${vip}:80 $static
                iapp::conf create ltm virtual-address /Common/${vip} traffic-group $::vs__traffic_group arp disabled route-advertisement enabled app-service none
            }
            macro {
            }
            presentation {
                section vs {
                    string vip required validator "IpAddress"
                    choice traffic_group tcl { return [iapp::get_items cm traffic-group] }
                }
                text {
                    vs.vip "Virtual IP"
                }
            }
            role-acl none
            run-as none
        }
    }
    description none
    ignore-verification false
    requires-bigip-version-max none
    requires-bigip-version-min none
    requires-modules { ltm }
    signing-key none
    tmpl-checksum none
    tmpl-signature none
}