Watermark exception

api/api/utils/watermark.py

@@ -5,9 +5,11 @@
 from textwrap import wrap
 
 from django.conf import settings
+from rest_framework import status
+from rest_framework.exceptions import APIException
 
 import requests
-from PIL import Image, ImageDraw, ImageFont
+from PIL import Image, ImageDraw, ImageFont, UnidentifiedImageError
 from sentry_sdk import capture_exception
 
 
@@ -25,6 +27,14 @@
 }
 
 
+class UpstreamWatermarkException(APIException):
+    status_code = status.HTTP_424_FAILED_DEPENDENCY
+    default_detail = (
+        "Could not render watermarked image due to upstream provider error."
+    )
+    default_code = "upstream_watermark_failure"
+
+
 class Dimension(Flag):
     """This enum represents the two dimensions of an image."""
 
@@ -169,12 +179,17 @@ def _open_image(url):
     logger = parent_logger.getChild("_open_image")
     try:
         response = requests.get(url, headers=HEADERS)
+        response.raise_for_status()
         img_bytes = BytesIO(response.content)
         img = Image.open(img_bytes)
     except requests.exceptions.RequestException as e:
+        capture_exception(e)
+        logger.error(f"Error requesting image: {e}")
+        raise UpstreamWatermarkException(f"{e}")
+    except UnidentifiedImageError as e:
         capture_exception(e)
         logger.error(f"Error loading image data: {e}")
-        return None, None
+        raise UpstreamWatermarkException(f"{e}")
 
     return img, img.getexif()
 

api/test/unit/views/test_image_views.py

@@ -8,6 +8,7 @@
 from django.http import HttpResponse
 
 import pytest
+from PIL import UnidentifiedImageError
 from requests import Request, Response
 
 from api.views.image_views import ImageViewSet
@@ -79,3 +80,31 @@ def test_thumbnail_uses_upstream_thumb_for_smk(
         thumb_call.return_value = mock_response
         api_client.get(f"/v1/images/{image.identifier}/thumb/")
     thumb_call.assert_called_once_with(ANY, image, expected_thumb_url)
+
+
+@pytest.mark.django_db
+def test_watermark_raises_424_for_invalid_image(api_client):
+    image = ImageFactory.create()
+    expected_error_message = (
+        "cannot identify image file <_io.BytesIO object at 0xffff86d8fec0>"
+    )
+
+    with patch("PIL.Image.open") as mock_open:
+        mock_open.side_effect = UnidentifiedImageError(expected_error_message)
+        res = api_client.get(f"/v1/images/{image.identifier}/watermark/")
+    assert res.status_code == 424
+    assert res.data["detail"] == expected_error_message
+
+
+@pytest.mark.django_db
+def test_watermark_raises_424_for_404_image(api_client):
+    image = ImageFactory.create()
+
+    with patch("requests.get") as mock_get:
+        mock_get.return_value = Response()
+        mock_get.return_value.status_code = 404
+        mock_get.return_value.url = image.url
+        mock_get.return_value.reason = "Not Found"
+        res = api_client.get(f"/v1/images/{image.identifier}/watermark/")
+    assert res.status_code == 424
+    assert res.data["detail"] == f"404 Client Error: Not Found for url: {image.url}"