do not attempt to re-create unvalidated image servers with .from_url

arkindex/images/managers.py

@@ -21,7 +21,7 @@ class ImageServerManager(models.Manager):
         servers = self \
             .using('default') \
             .annotate(image_url=models.Value(url, output_field=models.CharField())) \
-            .filter(validated=True, image_url__startswith=models.F('url'))
+            .filter(image_url__startswith=models.F('url'))
 
         servers_count = servers.count()
         if not servers_count:
@@ -49,4 +49,9 @@ class ImageServerManager(models.Manager):
                 f'The URL "{url}" matched multiple existing image servers'
             )
 
-        return servers.get()
+        image_server = servers.get()
+        if not image_server.validated:
+            raise ValueError(f'The {image_server.url} image server is not validated. '
+                             'Please ask an instance administrator to validate the IIIF server for this image.')
+
+        return image_server

arkindex/images/tests/test_imageserver.py

@@ -185,3 +185,13 @@ class TestImageServer(TestCase):
                 self.assertEqual(new_server.display_name, server_url)
                 self.assertTrue(new_server.validated)
                 new_server.delete()
+
+    def test_from_url_unvalidated_server(self):
+        """
+        Test that when a server already exists but is unvalidated
+        from_url does not attempt to create it again.
+        """
+        self.assertEqual(self.root_srv_2.validated, False)
+        with self.assertRaisesMessage(ValueError, "The http://server2.dev.teklia.com/iiif image server is not validated. Please ask an instance administrator to validate the IIIF server for this image."):
+            ImageServer.objects.from_url("http://server2.dev.teklia.com/iiif/path%2Fto%2Ffile.jpg")
+        self.assertEqual(ImageServer.objects.count(), 5)