Use logging instead

tcp_nat_proxy.py

@@ -1,12 +1,18 @@
 import argparse
 import asyncio
+import logging
 from collections import namedtuple
 from functools import partial
 
+logger = logging.getLogger(__name__)
+
 Route = namedtuple("Route", ["listen_port", "destination_host", "destination_port"])
 
 BUFFER_SIZE = 4096
 
+FORMAT = "%(levelname)s: %(message)s"
+logging.basicConfig(format=FORMAT)
+
 
 def destination_host_display(route: Route):
     return "{}:{}".format(route.destination_host, route.destination_port)
@@ -32,8 +38,8 @@ async def handle_client(route, local_reader, local_writer):
         await asyncio.gather(
             pipe(local_reader, remote_writer), pipe(remote_reader, local_writer)
         )
-    except ConnectionRefusedError:
-        print("Connection to {} refused".format(destination_host_display(route)))
+    except (ConnectionRefusedError, OSError):
+        logger.debug("Connection to {} refused".format(destination_host_display(route)))
         pass
     finally:
         local_writer.close()
@@ -43,7 +49,7 @@ async def create_proxy_pipe(route: Route):
     server = await asyncio.start_server(
         partial(handle_client, route), "0.0.0.0", route.listen_port
     )
-    print(
+    logger.info(
         "Routing from {} to {}".format(
             route.listen_port, destination_host_display(route)
         )
@@ -56,9 +62,12 @@ async def main():
     parser.add_argument(
         "-R", "--route", action="append", required=True, type=parse_argument
     )
+    parser.add_argument("--verbose", action="store_true")
     args = parser.parse_args()
+    logger.setLevel(logging.DEBUG if args.verbose else logging.INFO)
+
     servers = [create_proxy_pipe(route) for route in args.route]
-    print("Starting servers...")
+    logger.debug("Starting servers...")
     await asyncio.gather(*servers)
 
 
@@ -66,4 +75,4 @@ if __name__ == "__main__":
     try:
         asyncio.run(main())
     except KeyboardInterrupt:
-        print("Process terminated")
+        logger.error("Process terminated")