[fix] Fixed bridges renamed on OpenWrt 21 #243

Fixes #243

Co-authored-by: Federico Capoano <f.capoano@openwisp.io>

Author: pandafy

netjsonconfig/backends/openwrt/converters/interfaces.py

@@ -229,6 +229,21 @@ def __intermediate_device(self, interface):
             # A non-bridge interface that contains L2 options.
             return device
         device['type'] = 'bridge'
+        if not interface['ifname'].startswith('br-'):
+            # Add "br-" prefix to the bridge name
+            # for backward compatibility: OpenWrt <= 19
+            # automatically added the "br-" prefix to bridges,
+            # but later in OpenWrt 21 the bridge logic changed
+            # and that is no longer true, for that reason
+            # old configurations of OpenWISP made for OpenWrt 19
+            # which relied on the bridge names to be prefixed
+            # automatically with "br-" were breaking;
+            # to resolve this backward compatibility issue
+            # we now add the "br-" prefix automatically if needed.
+            interface['ifname'] = f'br-{interface["ifname"]}'
+        device['name'] = interface['ifname']
+        interface['device'] = device['name']
+
         # Add STP options only if STP is enabled
         self._add_options(
             'stp', self._bridge_interface_options['stp'], device, interface
@@ -439,7 +454,7 @@ def __get_device_config_for_interface(self, interface):
             del device_config['type']
         # ifname has been renamed to device in OpenWrt 21.02
         if device_config.get('type') == 'bridge':
-            interface['ifname'] = 'br-{}'.format(interface.pop('device'))
+            interface['ifname'] = interface.pop('device')
         elif interface.get('proto') not in self._proto_dsa_conflict:
             interface['ifname'] = interface.pop('device')
         return device_config

tests/openwrt/test_interfaces_dsa.py

@@ -874,21 +874,21 @@ def test_parse_simple_bridge(self):
     option proto 'none'
 
 config device 'device_lan'
-    option name 'lan'
+    option name 'br-lan'
     list ports 'eth0'
     list ports 'eth1'
     option stp '1'
     option type 'bridge'
 
 config interface 'lan'
-    option device 'lan'
+    option device 'br-lan'
     option gateway '10.0.0.10'
     list ipaddr '192.168.1.1/24'
     list ipaddr '10.0.0.1/24'
     option proto 'static'
 
 config interface 'lan_2'
-    option device 'lan'
+    option device 'br-lan'
     option proto 'dhcp'
 """