fix(controller): allow labels with trailing numbers

as per RFC 1123, domain labels are allowed a trailing number.

Author: Matthew Fisher

controller/api/serializers.py

@@ -251,7 +251,8 @@ def validate_domain(self, value):
         allowed = re.compile("^(?!-)[a-z0-9-]{1,63}(?<!-)$", re.IGNORECASE)
         for label in labels:
             match = allowed.match(label)
-            if not match or '--' in label or label[-1].isdigit() or label.isdigit():
+            if not match or '--' in label or label.isdigit() or \
+               len(labels) == 1 and any(char.isdigit() for char in label):
                 raise serializers.ValidationError('Hostname does not look valid.')
         if models.Domain.objects.filter(domain=value).exists():
             raise serializers.ValidationError(

controller/api/tests/test_domain.py

@@ -54,6 +54,7 @@ def test_manage_domain(self):
             'domain',
             'not.too.loooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong',
             '3com.com',
+            'w3.example.com',
             'MYDOMAIN.NET',
         ]
         for domain in test_domains: