Fix some content negotiation issues

Author: dralley

pulp_rust/app/views.py

@@ -7,6 +7,7 @@
 from rest_framework.viewsets import ViewSet
 from rest_framework.response import Response
 from rest_framework.exceptions import Throttled
+from rest_framework.renderers import BaseRenderer
 from django.core.exceptions import ObjectDoesNotExist
 from django.shortcuts import redirect, get_object_or_404
 
@@ -30,13 +31,22 @@
 log = logging.getLogger(__name__)
 
 BASE_CONTENT_URL = urljoin(settings.CONTENT_ORIGIN, settings.CONTENT_PATH_PREFIX)
-BASE_API_URL = urljoin(settings.CRATES_IO_API_HOSTNAME, "/pulp/cargo/")
-CRATES_IO_API = "/api/v1/crates/"
+
+
+class PlainTextRenderer(BaseRenderer):
+    """Renderer for text/plain responses (Cargo sends Accept: text/plain)."""
+
+    media_type = "text/plain"
+    format = "txt"
+
+    def render(self, data, accepted_media_type=None, renderer_context=None):
+        return data
 
 
 class ApiMixin:
     """Mixin to get index specific info."""
 
+    renderer_classes = [PlainTextRenderer]
     _distro = None
 
     @property
@@ -87,14 +97,17 @@ def initial(self, request, *args, **kwargs):
         super().initial(request, *args, **kwargs)
         domain_name = get_domain().name
         repo = self.kwargs["repo"]
+        scheme = request.META.get("HTTP_X_FORWARDED_PROTO", request.scheme)
+        host = request.META.get("HTTP_X_FORWARDED_HOST", request.get_host())
+        base_api_url = f"{scheme}://{host}/pulp/cargo/"
         if settings.DOMAIN_ENABLED:
             self.base_content_url = urljoin(BASE_CONTENT_URL, f"pulp/cargo/{domain_name}/{repo}/")
-            self.base_api_url = urljoin(BASE_API_URL, f"{domain_name}/{repo}/")
-            self.base_download_url = urljoin(BASE_API_URL, f"{domain_name}/{repo}{CRATES_IO_API}")
+            self.base_api_url = f"{base_api_url}{domain_name}/{repo}/"
+            self.base_download_url = f"{base_api_url}{domain_name}/{repo}/api/v1/crates"
         else:
             self.base_content_url = urljoin(BASE_CONTENT_URL, f"pulp/cargo/{repo}/")
-            self.base_api_url = urljoin(BASE_API_URL, f"{repo}/")
-            self.base_download_url = urljoin(BASE_API_URL, f"{repo}{CRATES_IO_API}")
+            self.base_api_url = f"{base_api_url}{repo}/"
+            self.base_download_url = f"{base_api_url}{repo}/api/v1/crates"
 
     @classmethod
     def urlpattern(cls):
@@ -221,13 +234,12 @@ class IndexRoot(ApiMixin, ViewSet):
     @extend_schema(responses={200: IndexRootSerializer}, summary="Get index info")
     def retrieve(self, request, repo):
         """Gets index route."""
-        return Response(
-            data={
-                "dl": self.base_download_url,
-                "api": self.base_api_url,
-                "auth-required": False,
-            }
-        )
+        data = {
+            "dl": self.base_download_url,
+            "api": self.base_api_url,
+            "auth-required": False,
+        }
+        return HttpResponse(json.dumps(data), content_type="application/json")
 
 
 class CargoDownloadApiView(APIView):
@@ -238,6 +250,7 @@ class CargoDownloadApiView(APIView):
     # Authentication disabled for now
     authentication_classes = []
     permission_classes = []
+    renderer_classes = [PlainTextRenderer]
 
     def get_full_path(self, base_path, pulp_domain=None):  # TODO: replace with ApiMixin?
         if settings.DOMAIN_ENABLED:

pulp_rust/tests/functional/api/test_cargo_api.py

@@ -31,6 +31,23 @@ def test_config_json(
     assert "/api/v1/crates/" in config["dl"]
 
 
+def test_config_json_accept_text_plain(
+    rust_repo_factory,
+    rust_distribution_factory,
+    cargo_registry_url,
+):
+    """config.json should be served when Accept: text/plain is sent (as Cargo does)."""
+    repository = rust_repo_factory()
+    distribution = rust_distribution_factory(repository=repository.pulp_href)
+
+    config_url = urljoin(cargo_registry_url(distribution.base_path), "config.json")
+    downloaded = download_file(config_url, headers={"Accept": "text/plain"})
+    assert downloaded.response_obj.status == 200
+
+    config = json.loads(downloaded.body)
+    assert "dl" in config
+
+
 def test_config_json_dl_points_to_pulp(
     rust_remote_factory,
     rust_repo_factory,