Added runserver validation to detect if DEBUG=False and ALLOWED_HOSTS is empty.

Refs #19875.

django/core/management/commands/runserver.py

@@ -40,6 +40,11 @@ class Command(BaseCommand):
         return get_internal_wsgi_application()
 
     def handle(self, addrport='', *args, **options):
+        from django.conf import settings
+
+        if not settings.DEBUG and not settings.ALLOWED_HOSTS:
+            raise CommandError('You must set settings.ALLOWED_HOSTS if DEBUG is False.')
+
         self.use_ipv6 = options.get('use_ipv6')
         if self.use_ipv6 and not socket.has_ipv6:
             raise CommandError('Your Python does not support IPv6.')

tests/admin_scripts/tests.py

@@ -1192,6 +1192,21 @@ class ManageRunserver(AdminScriptTestCase):
         self.cmd.handle(addrport="deadbeef:7654")
         self.assertServerSettings('deadbeef', '7654')
 
+class ManageRunserverEmptyAllowedHosts(AdminScriptTestCase):
+    def setUp(self):
+        self.write_settings('settings.py', sdict={
+            'ALLOWED_HOSTS': [],
+            'DEBUG': False,
+        })
+
+    def tearDown(self):
+        self.remove_settings('settings.py')
+
+    def test_empty_allowed_hosts_error(self):
+        out, err = self.run_manage(['runserver'])
+        self.assertNoOutput(out)
+        self.assertOutput(err, 'CommandError: You must set settings.ALLOWED_HOSTS if DEBUG is False.')
+
 
 ##########################################################################
 # COMMAND PROCESSING TESTS