team_communication: automatically detect target ip address

Closes #578.

bitbots_team_communication/bitbots_team_communication/bitbots_team_communication/communication.py

@@ -1,5 +1,5 @@
 import socket
-from ipaddress import IPv4Address
+from ipaddress import AddressValueError, IPv4Address
 from typing import List, Optional
 
 from rclpy.node import Node
@@ -11,7 +11,19 @@ def __init__(self, node: Node, logger, team_id, robot_id):
 
         self.buffer_size: int = 1024
         self.socket: Optional[socket.socket] = None
-        self.target_ip: IPv4Address = IPv4Address(node.get_parameter("target_ip").value)
+        if node.get_parameter("detect_target_ip").value:
+            try:
+                # automatically detect from subnet
+                import netifaces
+
+                self.target_ip: IPv4Address = IPv4Address(
+                    netifaces.ifaddresses(node.get_parameter("wifi_interface"))[netifaces.AF_INET][0]["broadcast"]
+                )
+            except (ImportError, ValueError, KeyError, AddressValueError):
+                self.logger.warn("Could not detect broadcast address, falling back to configured address")
+                self.target_ip = None
+        if self.target_ip is None:
+            self.target_ip: IPv4Address = IPv4Address(node.get_parameter("target_ip").value)
 
         if self.target_ip.is_loopback:
             # local mode on loopback device, bind to port depending on bot id and team id

bitbots_team_communication/bitbots_team_communication/config/team_communication_config.yaml

@@ -1,21 +1,14 @@
 team_comm:
   ros__parameters:
-    # UDP broadcast address is the highest IP in the subnet e.g. 172.20.255.255
-    # Sets local mode if set to loopback (127.0.0.1)
+    # Automatically detect UDP broadcast address
+    detect_target_ip: true
+    # Fallback, only used if detect_target_ip is false. This should be the highest IP in the subnet e.g. 172.20.255.255
     target_ip: 192.168.255.255
 
     # Only used in non local mode with specific target_ip
     target_port: 3737
     receive_port: 3737
 
-    # Only used in local mode on loopback
-    # the team communication will bind to one of these ports and send to the other ports, depending on its bot_id
-    local_target_ports:
-      - 4001
-      - 4002
-      - 4003
-      - 4004
-
     # Rate of published messages in Hz
     rate: 10