def create_srv_entry(srv_name, ip, port):
    """Create a SRV entry based on the supplied data

    Arguments:
        srv_name (string): service ID that the new SRV-entry should represent
        port (string): TCP/IP port that the new agent should pretend to listen on
        ip (string): IP address that the new agent hould pretend to listen on

    Returns:
        SRV entry dict mimicing the one returned by MesosDNS
    """
    res = {}
    res['service'] = "_{}._tcp.marathon.mesos".format(srv_name)
    res['host'] = "{}-74b1w-s1.marathon.mesos.".format(srv_name)
    res['ip'] = ip
    res['port'] = port

    return res