logging. forward_host default

Author: Koos85

README.md

@@ -19,6 +19,8 @@ Variable            | Default                        | Description
 `LOG_COLORIZED`     | `0`                            | Log using colors (`0`=disabled, `1`=enabled).
 `LOG_FMT`           | `%y%m%d %H:%M:%S`              | Log format prefix.
 `LISTEN_PORT`       | `2055`                         | Port to listen to for flow packets
+`FORWARD_HOST`      | `127.0.0.1`                    | Forward UDP traffic to this host (only applicable if FORWARD_PORTS is set).
+`FORWARD_PORTS`     | _none_                         | Forward UDP traffic to these local ports for other listeners (comma separate for multiple ports).
 
 ## Docker build
 

lib/server.py

@@ -8,20 +8,26 @@
 from .state import subscriptions
 
 LISTEN_PORT = int(os.getenv('LISTEN_PORT', '2055'))
-FORWARD_HOST = os.getenv('FORWARD_HOST', 'host.docker.internal')
+FORWARD_HOST = os.getenv('FORWARD_HOST', '127.0.0.1')
 FORWARD_PORTS = os.getenv('FORWARD_PORTS')
 FORWARD = [
     (FORWARD_HOST, pt)
     for pt in map(int, FORWARD_PORTS.split(','))
 ] if FORWARD_PORTS else []
 assert all(0 < pt < 65536 and pt != LISTEN_PORT for _, pt in FORWARD)
+assert len(FORWARD) == len(set(FORWARD))
 
 COMMON_HEADER_FMT = '>HHL'
 COMMON_HEADER_SZ = 8
 
 
 class ServerProtocol(asyncio.Protocol):
 
+    def __init__(self):
+        super().__init__()
+        self.log_unsupported_version = 0
+        self.log_failed_to_forward = set()
+
     def connection_made(self, transport):
         self.transport = transport
 
@@ -36,16 +42,18 @@ def datagram_received(self, data, addr):
         ) = struct.unpack(COMMON_HEADER_FMT, data[:COMMON_HEADER_SZ])
 
         if version not in (5, 9, 10):
-            # TODO 10 times
-            logging.warning('unsupported netflow version')
+            if self.log_unsupported_version < 10:
+                self.log_unsupported_version += 1
+                logging.warning('unsupported netflow version')
             return
 
         for dest in FORWARD:
             try:
                 self.transport.sendto(data, dest)
             except Exception:
-                # TODO 1 time / conn
-                logging.warning('failed to forward package')
+                if dest not in self.log_failed_to_forward:
+                    self.log_failed_to_forward.add(dest)
+                    logging.warning(f'failed to forward package to {dest}')
 
         # v5 has no templates so could be ignored when no checks are listening
         if version == 5 and not subscriptions: