def format_erl_node_name(app_name, hostname):
    """Formats full node name for an erlang VM hosted on docker based on app_name and hostname.
    NOTE: Hostnames are also used as docker names!
    app_name - application name, e.g.: 'op_ccm', 'globalregistry'
    hostname - hostname aquired by format_*_hostname
    """
    return '{0}@{1}'.format(app_name, hostname)