wireguard: T3763: Fixed uninitialized port issue

The commit fixes the problem, when port availability check is
triggered even if a port for WireGuard interface is not defined
(randomized port, default behavior).

1 files changed, 6 insertions, 6 deletions

diff --git a/src/conf_mode/interfaces-wireguard.py b/src/conf_mode/interfaces-wireguard.py
index 68181465e..9baf5b6e9 100755
--- a/src/conf_mode/interfaces-wireguard.py
+++ b/src/conf_mode/interfaces-wireguard.py
@@ -74,12 +74,12 @@ def verify(wireguard):
     if 'peer' not in wireguard:
         raise ConfigError('At least one Wireguard peer is required!')
 
-    listen_port = int(wireguard['port'])
-    if 'port' in wireguard and check_port_availability('0.0.0.0', listen_port,
-                                                       'udp') is not True:
-        raise ConfigError(
-            f'The UDP port {listen_port} is busy or unavailable and cannot be used for the interface'
-        )
+    if 'port' in wireguard:
+        listen_port = int(wireguard['port'])
+        if check_port_availability('0.0.0.0', listen_port, 'udp') is not True:
+            raise ConfigError(
+                f'The UDP port {listen_port} is busy or unavailable and cannot be used for the interface'
+            )
 
     # run checks on individual configured WireGuard peer
     for tmp in wireguard['peer']: