Made interface to an optional parameter

broker/l2tp_broker.cfg.example

@@ -3,7 +3,7 @@
 address=127.0.0.1
 ; Ports where the broker will listen on
 port=53,123,8942
-; Interface with that IP address
+; Interface with that IP address (optional)
 interface=lo
 ; Maximum number of tunnels that will be allowed by the broker.
 ; On a cheap VPS, more than 256 tunnels usually do not make sense.

broker/src/tunneldigger_broker/main.py

@@ -91,11 +91,18 @@
 broker_host = config.get('broker', 'address')
 for port in config.get('broker', 'port').split(','):
     try:
-        broker_instance = broker.Broker(
-            (broker_host, int(port)),
-            config.get('broker', 'interface'),
-            tunnel_manager,
-        )
+        if config.has_option('broker', 'interface'):
+            broker_instance = broker.Broker(
+                (broker_host, int(port)),
+                config.get('broker', 'interface'),
+                tunnel_manager,
+            )
+        else:
+            broker_instance = broker.Broker(
+                (broker_host, int(port)),
+                None,
+                tunnel_manager,
+            )
         logger.info("Listening on %s:%d." % broker_instance.address)
     except ValueError:
         logger.warning("Malformed port number '%s', skipping." % port)

broker/src/tunneldigger_broker/network.py

@@ -36,7 +36,8 @@ def __init__(self, address, interface):
         # Since we want all tunnel and tunnel control traffic to use the same port for
         # all clients we enable reuse of ports on the sockets we create.
         self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEPORT, 1)
-        self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_BINDTODEVICE, interface.encode('utf-8'))
+        if interface is not None:
+            self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_BINDTODEVICE, interface.encode('utf-8'))
         self.socket.bind(address)
 
         self.address = address

docs/server.rst

@@ -177,7 +177,7 @@ changed and some that can be left as default:
 
 * **port** should be configured with the external port (or ports separated by commas) that the clients will use to connect with the broker.
 
-* **interface** should be configured with the name of the external interface that the clients will connect to.
+* **interface** is a optional parameter and should be configured with the name of the external interface that the clients will connect to.
 
 * Hooks in the **hooks** section should be configured with paths to executable scripts that will be called when certain events occur in the broker. They are empty by default which means that tunnels will be established but they will not be configured.