Merge pull request #2 from AsimovBio/cors-options

Enables OPTIONS HTTP method for preflight requests in the FE

src/gcp_storage_emulator/handlers/objects.py

@@ -537,3 +537,13 @@ def batch(request, response, storage, *args, **kwargs):
  response.write("\r\n\r\n")
 
  response.write("--{}--".format(boundary))
+
+
+def options(request, response, storage, *args, **kwargs):
+ response.write("HTTP/1.1 200 OK\r\n")
+ response.write("Content-Type: text/html; charset=UTF-8\r\n")
+ response.write("allow: OPTIONS,GET,POST,PUT,DELETE,PATCH\r\n")
+ response.write("access-control-allow-origin: *\r\n")
+ response.write(
+ "access-control-allow-methods: GET,POST,PUT,PATCH,DELETE,OPTIONS\r\n"
+ )

src/gcp_storage_emulator/server.py

@@ -21,6 +21,7 @@
 PUT = "PUT"
 DELETE = "DELETE"
 PATCH = "PATCH"
+OPTIONS = "OPTIONS"
 
 
 def _wipe_data(req, res, storage):
@@ -39,56 +40,64 @@ def _health_check(req, res, storage):
 
 
 HANDLERS = (
- (r"^{}/b$".format(settings.API_ENDPOINT), {GET: buckets.ls, POST: buckets.insert}),
+ (
+ r"^{}/b$".format(settings.API_ENDPOINT),
+ {GET: buckets.ls, POST: buckets.insert, OPTIONS: objects.options},
+ ),
  (
  r"^{}/b/(?P<bucket_name>[-.\w]+)$".format(settings.API_ENDPOINT),
- {GET: buckets.get, DELETE: buckets.delete},
+ {GET: buckets.get, DELETE: buckets.delete, OPTIONS: objects.options},
  ),
  (
  r"^{}/b/(?P<bucket_name>[-.\w]+)/o$".format(settings.API_ENDPOINT),
- {GET: objects.ls},
+ {GET: objects.ls, OPTIONS: objects.options},
  ),
  (
  r"^{}/b/(?P<bucket_name>[-.\w]+)/o/(?P<object_id>.*[^/]+)/copyTo/b/".format(
  settings.API_ENDPOINT
  )
  + r"(?P<dest_bucket_name>[-.\w]+)/o/(?P<dest_object_id>.*[^/]+)$",
- {POST: objects.copy},
+ {POST: objects.copy, OPTIONS: objects.options},
  ),
  (
  r"^{}/b/(?P<bucket_name>[-.\w]+)/o/(?P<object_id>.*[^/]+)/compose$".format(
  settings.API_ENDPOINT
  ),
- {POST: objects.compose},
+ {POST: objects.compose, OPTIONS: objects.options},
  ),
  (
  r"^{}/b/(?P<bucket_name>[-.\w]+)/o/(?P<object_id>.*[^/]+)$".format(
  settings.API_ENDPOINT
  ),
- {GET: objects.get, DELETE: objects.delete, PATCH: objects.patch},
+ {
+ GET: objects.get,
+ DELETE: objects.delete,
+ PATCH: objects.patch,
+ OPTIONS: objects.options,
+ },
  ),
  # Non-default API endpoints
  (
  r"^{}/b/(?P<bucket_name>[-.\w]+)/o$".format(settings.UPLOAD_API_ENDPOINT),
- {POST: objects.insert, PUT: objects.upload_partial},
+ {POST: objects.insert, PUT: objects.upload_partial, OPTIONS: objects.options},
  ),
  (
  r"^{}/b/(?P<bucket_name>[-.\w]+)/o/(?P<object_id>.*[^/]+)$".format(
  settings.DOWNLOAD_API_ENDPOINT
  ),
- {GET: objects.download},
+ {GET: objects.download, OPTIONS: objects.options},
  ),
  (
  r"^{}$".format(settings.BATCH_API_ENDPOINT),
- {POST: objects.batch},
+ {POST: objects.batch, OPTIONS: objects.options},
  ),
  # Internal API, not supported by the real GCS
- (r"^/$", {GET: _health_check}), # Health check endpoint
- (r"^/wipe$", {GET: _wipe_data}), # Wipe all data
+ (r"^/$", {GET: _health_check, OPTIONS: objects.options}), # Health check endpoint
+ (r"^/wipe$", {GET: _wipe_data, OPTIONS: objects.options}), # Wipe all data
  # Public file serving, same as object.download and signed URLs
  (
  r"^/(?P<bucket_name>[-.\w]+)/(?P<object_id>.*[^/]+)$",
- {GET: objects.download, PUT: objects.xml_upload},
+ {GET: objects.download, PUT: objects.xml_upload, OPTIONS: objects.options},
  ),
 )
 
@@ -318,9 +327,12 @@ def handle(self, method):
  request = Request(self._request_handler, method)
  response = Response(self._request_handler)
 
+ response["Access-Control-Allow-Origin"] = "*"
+
  for regex, handlers in HANDLERS:
  pattern = re.compile(regex)
  match = pattern.fullmatch(request.path)
+
  if match:
  request.set_match(match)
  handler = handlers.get(method)
@@ -341,7 +353,7 @@ def handle(self, method):
  "Method not implemented: {} - {}".format(request.method, request.path)
  )
  response.status = HTTPStatus.NOT_IMPLEMENTED
-
+ 
  response.close()
 
 
@@ -370,6 +382,10 @@ def do_PATCH(self):
  router = Router(self)
  router.handle(PATCH)
 
+ def do_OPTIONS(self):
+ router = Router(self)
+ router.handle(OPTIONS)
+
  def log_message(self, format, *args):
  logger.info(format % args)
 

tests/test_main.py

@@ -76,3 +76,12 @@ def test_path_does_not_exist(self):
  response = requests.get(url)
  self.assertEqual(response.status_code, 501)
  self.assertEqual(response.content, "".encode("utf-8"))
+
+ def test_options(self):
+ url = self._url("/")
+ response = requests.options(url)
+ self.assertEqual(response.status_code, 200)
+ self.assertTrue(
+ "GET,POST,PUT,PATCH,DELETE,OPTIONS"
+ in response.headers["access-control-allow-methods"]
+ )