Validate inventory hostnames via DNS resolution

wif2ansible/network.py

@@ -15,6 +15,14 @@ def get_ip(hostname: str) -> Optional[str]:
     except socket.error:
         return None
 
+def is_valid_hostname(hostname: str) -> bool:
+    """
+    Checks if a hostname resolves to an IP.
+    """
+    if not hostname:
+        return False
+    return get_ip(hostname) is not None
+
 def to_mgt_ip(name_or_ip: str) -> Optional[str]:
     """
     Mimics the Ruby script's to_mgt_ip logic: