import re
from importlib import import_module
from urllib.parse import urljoin
from django.conf import settings
from django.core.exceptions import ValidationError as DjangoValidationError
from django.urls import NoReverseMatch
from rest_framework import status
from rest_framework.response import Response
from rest_framework.reverse import reverse
from rest_framework.views import (
APIView,
exception_handler as original_exception_handler,
set_rollback,
)
from normandy.base.api.utils import get_api_endpoints
from normandy.base.decorators import api_cache_control
class APIRootView(APIView):
"""
An API root view that lists the urls that share it's version namespace.
"""
_ignore_model_permissions = True
exclude_from_schema = True
urlconf = None
@api_cache_control(max_age=settings.API_CACHE_TIME)
def get(self, request, *args, **kwargs):
ret = {}
# Get the version namespace
namespace = getattr(request.resolver_match, "namespace", "")
for ns in namespace.split(":"):
if re.match(r"v[0-9]+", ns, re.I):
namespace = ns
break
if self.urlconf:
urlconf = self.urlconf
else:
urlconf = import_module(settings.ROOT_URLCONF)
endpoints = get_api_endpoints(urlconf.urlpatterns)
for endpoint in sorted(endpoints, key=lambda e: e["pattern"].name):
name = endpoint["pattern"].name
if endpoint["method"] == "GET" and namespace in endpoint["namespace"].split(":"):
allow_cdn = getattr(endpoint["pattern"], "allow_cdn", True)
if not allow_cdn and settings.APP_SERVER_URL:
base = settings.APP_SERVER_URL
else:
base = request.build_absolute_uri()
try:
full_name = (
f'{endpoint["namespace"]}:{name}' if endpoint["namespace"] else name
)
path = reverse(full_name, *args, **kwargs)
except NoReverseMatch:
continue
full_url = urljoin(base, path)
ret[name] = full_url
return Response(ret)
def exception_handler(exc, context):
"""
Returns the response that should be used for any given exception.
Adds support the DRF default to also handle django.core.exceptions.ValidationError
Any unhandled exceptions may return `None`, which will cause a 500 error
to be raised.
"""
response = original_exception_handler(exc, context)
if response:
return response
elif isinstance(exc, DjangoValidationError):
data = {"messages": exc.messages}
set_rollback()
return Response(data, status=status.HTTP_400_BAD_REQUEST)
return None
