TCP iRule to find HTTP headers

I think you could limit the iRule to this:

when CLIENT_ACCEPTED {
    HTTP::disable
    TCP::collect 4
}

when CLIENT_DATA {
    if { [TCP::payload 4] contains "GET" } {
        HTTP::enable
    }
    TCP::release
}

when HTTP_REQUEST {
    my irule
}

when HTTP_RESPONSE {
    my irule
}

I'll expect the HTTP_REQUEST and HTTP_RESPONSE events will not be triggered when the HTTP profile is disabled.