Syslog-ng with Python tf functions

Output

I'm the function: host=localhost 1st arg=first_arg 2nd arg=second_arg

syslog-ng.conf

@version: 3.7
@include "scl.conf"

python {
def fn_name(logmsg, arg1, arg2):
  host = getattr(logmsg, "HOST")
  return "I'm the function: host={} 1st arg={} 2nd arg={}\n".format(host, arg1, arg2)
};

source s_local {
	internal();
  network(
      ip(
          0.0.0.0
      ),
      port(
          1514
      ),
      transport("tcp")
  );
};

destination d_local {
	file("/tmp/messages" template("$(python fn_name first_arg second_arg)"));
};

log {
	source(s_local);
	destination(d_local);
};