From 68473e7df3e27abaabc5ea0e111e54ddf9a9fd96 Mon Sep 17 00:00:00 2001
From: Joe Shimkus <35382397+jshimkus-rh@users.noreply.github.com>
Date: Tue, 17 Oct 2023 10:22:57 -0400
Subject: [PATCH] (chore) Add api fallback exception handler. (#430)

Signed-off-by: Joe Shimkus <jshimkus@redhat.com>
---
 src/aap_eda/api/exceptions.py                 | 20 ++++++++++
 src/aap_eda/settings/default.py               |  1 +
 .../integration/api/test_fallback_handler.py  | 38 +++++++++++++++++++
 3 files changed, 59 insertions(+)
 create mode 100644 tests/integration/api/test_fallback_handler.py

diff --git a/src/aap_eda/api/exceptions.py b/src/aap_eda/api/exceptions.py
index 497f84c62..bbe0195e8 100644
--- a/src/aap_eda/api/exceptions.py
+++ b/src/aap_eda/api/exceptions.py
@@ -11,6 +11,7 @@
 #  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 #  See the License for the specific language governing permissions and
 #  limitations under the License.
+from django.conf import settings
 from django.utils.translation import gettext_lazy as _
 from rest_framework import status
 from rest_framework.exceptions import (
@@ -20,6 +21,8 @@
     NotFound,
     PermissionDenied,
 )
+from rest_framework.response import Response
+from rest_framework.views import exception_handler
 
 __all__ = (
     "AuthenticationFailed",
@@ -29,9 +32,26 @@
     "Conflict",
     "Unprocessable",
     "PermissionDenied",
+    "api_fallback_handler",
 )
 
 
+def api_fallback_handler(exc, context):
+    response = exception_handler(exc, context)
+    if (response is None) and (not settings.DEBUG):
+        response = Response(
+            status=status.HTTP_500_INTERNAL_SERVER_ERROR,
+            data={
+                "detail": (
+                    "Unexpected server error"
+                    "; contact your system administrator"
+                )
+            },
+        )
+        response["context"] = context
+    return response
+
+
 class BadRequest(APIException):
     status = status.HTTP_400_BAD_REQUEST
     default_code = "bad_request"
diff --git a/src/aap_eda/settings/default.py b/src/aap_eda/settings/default.py
index 92411d1ea..87b1eb307 100644
--- a/src/aap_eda/settings/default.py
+++ b/src/aap_eda/settings/default.py
@@ -238,6 +238,7 @@ def _get_secret_key() -> str:
         "aap_eda.api.permissions.RoleBasedPermission",
     ],
     "TEST_REQUEST_DEFAULT_FORMAT": "json",
+    "EXCEPTION_HANDLER": "aap_eda.api.exceptions.api_fallback_handler",
 }
 
 # ---------------------------------------------------------
diff --git a/tests/integration/api/test_fallback_handler.py b/tests/integration/api/test_fallback_handler.py
new file mode 100644
index 000000000..d1390f081
--- /dev/null
+++ b/tests/integration/api/test_fallback_handler.py
@@ -0,0 +1,38 @@
+from unittest import mock
+
+import pytest
+from rest_framework import status
+from rest_framework.test import APIClient
+
+from tests.integration.constants import api_url_v1
+
+
+class FallbackException(Exception):
+    pass
+
+
+def raise_exception(self, request):
+    raise FallbackException
+
+
+@pytest.mark.django_db
+@mock.patch(
+    "aap_eda.api.views.project.ProjectViewSet.list", new=raise_exception
+)
+def test_debug_unexpected_exception(client: APIClient, settings):
+    settings.DEBUG = True
+    with pytest.raises(FallbackException):
+        client.get(f"{api_url_v1}/projects/")
+
+
+@pytest.mark.django_db
+@mock.patch(
+    "aap_eda.api.views.project.ProjectViewSet.list", new=raise_exception
+)
+def test_non_debug_unexpected_exception(client: APIClient, settings):
+    settings.DEBUG = False
+    response = client.get(f"{api_url_v1}/projects/")
+    assert response.status_code == status.HTTP_500_INTERNAL_SERVER_ERROR
+
+    data = response.json()
+    assert data["detail"].startswith("Unexpected server error")