class Mangum:
app: ASGIApp
debug: bool = False
enable_lifespan: bool = True
log_level: str = "info"
def __post_init__(self) -> None:
self.logger = get_logger(log_level=self.log_level)
if self.enable_lifespan:
loop = asyncio.get_event_loop()
self.lifespan = Lifespan(self.app, logger=self.logger)
loop.create_task(self.lifespan.run())
loop.run_until_complete(self.lifespan.wait_startup())
def __call__(
self, event: typing.Dict[str, typing.Any],
context: typing.Dict[str,
typing.Any]) -> typing.Dict[str, typing.Any]:
try:
response = self.handler(event, context)
except Exception as exc:
if self.debug:
content = traceback.format_exc()
return make_response(content, status_code=500)
raise exc
else:
return response
def handler(
self, event: typing.Dict[str, typing.Any],
context: typing.Dict[str,
typing.Any]) -> typing.Dict[str, typing.Any]:
if "httpMethod" in event:
from mangum.protocols.http import handle_http
response = handle_http(self.app, event, context)
else:
try:
from mangum.protocols.websockets import handle_ws
except ImportError as exc: # pragma: nocover
raise exc
response = handle_ws(self.app, event, context)
if self.enable_lifespan:
loop = asyncio.get_event_loop()
loop.run_until_complete(self.lifespan.wait_shutdown())
return response
class Mangum:
app: ASGIApp
enable_lifespan: bool = True
api_gateway_base_path: typing.Optional[str] = None
log_level: str = "info"
def __post_init__(self) -> None:
self.logger = get_logger(log_level=self.log_level)
if self.enable_lifespan:
loop = asyncio.get_event_loop()
self.lifespan = Lifespan(self.app, logger=self.logger)
loop.create_task(self.lifespan.run())
loop.run_until_complete(self.lifespan.wait_startup())
def __call__(self, event: dict, context: dict) -> dict:
try:
response = self.handler(event, context)
except BaseException as exc:
raise exc
return response
def strip_base_path(self, path: str) -> str:
if self.api_gateway_base_path:
script_name = "/" + self.api_gateway_base_path
if path.startswith(script_name):
path = path[len(script_name) :]
return urllib.parse.unquote(path or "/")
def handler(self, event: dict, context: dict) -> dict:
if "httpMethod" in event:
response = self.handle_http(event, context)
else:
response = self.handle_ws(event, context)
if self.enable_lifespan:
loop = asyncio.get_event_loop()
loop.run_until_complete(self.lifespan.wait_shutdown())
return response
def handle_http(self, event: dict, context: dict) -> dict:
server, client = get_server_and_client(event)
headers = event.get("headers") or {}
headers_key_value_pairs = [
[k.lower().encode(), v.encode()] for k, v in headers.items()
]
multi_value_query_string_params = event["multiValueQueryStringParameters"]
query_string = (
urllib.parse.urlencode(multi_value_query_string_params, doseq=True).encode()
if multi_value_query_string_params
else b""
)
scope = {
"type": "http",
"http_version": "1.1",
"method": event["httpMethod"],
"headers": headers_key_value_pairs,
"path": self.strip_base_path(event["path"]),
"raw_path": None,
"root_path": "",
"scheme": headers.get("X-Forwarded-Proto", "https"),
"query_string": query_string,
"server": server,
"client": client,
"asgi": {"version": "3.0"},
"aws.event": event,
"aws.context": context,
}
is_binary = event.get("isBase64Encoded", False)
body = event["body"] or b""
if is_binary:
body = base64.b64decode(body)
elif not isinstance(body, bytes):
body = body.encode()
asgi_cycle = ASGIHTTPCycle(scope, is_binary=is_binary, logger=self.logger)
asgi_cycle.put_message(
{"type": "http.request", "body": body, "more_body": False}
)
response = asgi_cycle(self.app)
return response
def handle_ws(self, event: dict, context: dict) -> dict:
if __ERR__: # pragma: no cover
raise ImportError(__ERR__)
request_context = event["requestContext"]
connection_id = request_context.get("connectionId")
domain_name = request_context.get("domainName")
stage = request_context.get("stage")
event_type = request_context["eventType"]
endpoint_url = f"https://{domain_name}/{stage}"
if event_type == "CONNECT":
# The initial connect event. Parse and store the scope for the connection
# in DynamoDB to be retrieved in subsequent message events for this request.
server, client = get_server_and_client(event)
# The scope headers must be JSON serializable to store in DynamoDB, but
# they will be parsed on the MESSAGE event.
headers = event.get("headers") or {}
root_path = event["requestContext"]["stage"]
scope = {
"type": "websocket",
"path": "/",
"headers": headers,
"raw_path": None,
"root_path": root_path,
"scheme": headers.get("X-Forwarded-Proto", "wss"),
"query_string": "",
"server": server,
"client": client,
"aws": {"event": event, "context": context},
}
connection_table = ConnectionTable()
status_code = connection_table.update_item(
connection_id, scope=json.dumps(scope)
)
if status_code != 200: # pragma: no cover
return make_response("Error", status_code=500)
return make_response("OK", status_code=200)
elif event_type == "MESSAGE":
connection_table = ConnectionTable()
item = connection_table.get_item(connection_id)
if not item: # pragma: no cover
return make_response("Error", status_code=500)
# Retrieve and deserialize the scope entry created in the connect event for
# the current connection.
scope = json.loads(item["scope"])
# Ensure the scope definition complies with the ASGI spec.
query_string = scope["query_string"]
headers = scope["headers"]
headers = [[k.encode(), v.encode()] for k, v in headers.items()]
query_string = query_string.encode()
scope.update({"headers": headers, "query_string": query_string})
asgi_cycle = ASGIWebSocketCycle(
scope,
endpoint_url=endpoint_url,
connection_id=connection_id,
connection_table=connection_table,
)
asgi_cycle.app_queue.put_nowait({"type": "websocket.connect"})
asgi_cycle.app_queue.put_nowait(
{
"type": "websocket.receive",
"path": "/",
"bytes": None,
"text": event["body"],
}
)
try:
asgi_cycle(self.app)
except ASGIWebSocketCycleException: # pragma: no cover
return make_response("Error", status_code=500)
return make_response("OK", status_code=200)
elif event_type == "DISCONNECT":
connection_table = ConnectionTable()
status_code = connection_table.delete_item(connection_id)
if status_code != 200: # pragma: no cover
return make_response("WebSocket disconnect error.", status_code=500)
return make_response("OK", status_code=200)
return make_response("Error", status_code=500) # pragma: no cover