I am using FastAPI with Pydantic.
My problem - I need to raise ValueError using Pydantic
from fastapi import FastAPI
from pydantic import BaseModel, validator
from fastapi import Depends, HTTPException
app = FastAPI()
class RankInput(BaseModel):
rank: int
#validator('rank')
def check_if_value_in_range(cls, v):
"""
check if input rank is within range
"""
if not 0 < v < 1000001:
raise ValueError("Rank Value Must be within range (0,1000000)")
#raise HTTPException(status_code=400, detail="Rank Value Error") - this works But I am looking for a solution using ValueError
return v
def get_info_by_rank(rank):
return rank
#app.get('/rank/{rank}')
async def get_rank(value: RankInput = Depends()):
result = get_info_by_rank(value.rank)
return result
this piece of code gives Internal Server Error when a ValueError is raised
INFO: 127.0.0.1:59427 - "GET /info/?rank=-1 HTTP/1.1" 500 Internal Server Error
ERROR: Exception in ASGI application
Traceback (most recent call last):
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/uvicorn/protocols/http/h11_impl.py", line 396, in run_asgi
result = await app(self.scope, self.receive, self.send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/uvicorn/middleware/proxy_headers.py", line 45, in __call__
return await self.app(scope, receive, send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/fastapi/applications.py", line 199, in __call__
await super().__call__(scope, receive, send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/applications.py", line 111, in __call__
await self.middleware_stack(scope, receive, send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/middleware/errors.py", line 181, in __call__
raise exc from None
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/middleware/errors.py", line 159, in __call__
await self.app(scope, receive, _send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/exceptions.py", line 82, in __call__
raise exc from None
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/exceptions.py", line 71, in __call__
await self.app(scope, receive, sender)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/routing.py", line 566, in __call__
await route.handle(scope, receive, send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/routing.py", line 227, in handle
await self.app(scope, receive, send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/routing.py", line 41, in app
response = await func(request)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/fastapi/routing.py", line 195, in app
dependency_overrides_provider=dependency_overrides_provider,
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/fastapi/dependencies/utils.py", line 550, in solve_dependencies
solved = await run_in_threadpool(call, **sub_values)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/concurrency.py", line 34, in run_in_threadpool
return await loop.run_in_executor(None, func, *args)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/concurrent/futures/thread.py", line 57, in run
result = self.fn(*self.args, **self.kwargs)
File "pydantic/main.py", line 400, in pydantic.main.BaseModel.__init__
pydantic.error_wrappers.ValidationError: 1 validation error for GetInput
rank
ValueError() takes no keyword arguments (type=type_error)
ERROR:uvicorn.error:Exception in ASGI application
Traceback (most recent call last):
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/uvicorn/protocols/http/h11_impl.py", line 396, in run_asgi
result = await app(self.scope, self.receive, self.send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/uvicorn/middleware/proxy_headers.py", line 45, in __call__
return await self.app(scope, receive, send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/fastapi/applications.py", line 199, in __call__
await super().__call__(scope, receive, send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/applications.py", line 111, in __call__
await self.middleware_stack(scope, receive, send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/middleware/errors.py", line 181, in __call__
raise exc from None
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/middleware/errors.py", line 159, in __call__
await self.app(scope, receive, _send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/exceptions.py", line 82, in __call__
raise exc from None
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/exceptions.py", line 71, in __call__
await self.app(scope, receive, sender)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/routing.py", line 566, in __call__
await route.handle(scope, receive, send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/routing.py", line 227, in handle
await self.app(scope, receive, send)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/routing.py", line 41, in app
response = await func(request)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/fastapi/routing.py", line 195, in app
dependency_overrides_provider=dependency_overrides_provider,
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/fastapi/dependencies/utils.py", line 550, in solve_dependencies
solved = await run_in_threadpool(call, **sub_values)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/starlette/concurrency.py", line 34, in run_in_threadpool
return await loop.run_in_executor(None, func, *args)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/concurrent/futures/thread.py", line 57, in run
result = self.fn(*self.args, **self.kwargs)
File "pydantic/main.py", line 400, in pydantic.main.BaseModel.__init__
pydantic.error_wrappers.ValidationError: 1 validation error for GetInput
rank
ValueError() takes no keyword arguments (type=type_error)
I also checked https://github.com/tiangolo/fastapi/issues/2180.
But I was not able to figure out a solution.
What I need to do is Raise ValueError with a Custom Status Code.
Note - I know I can get the Job Done by raising HTTPException.
But I am looking for a solution using ValueError
Could you tell me where I am going wrong?
Have Also Posted this Issue on Github - https://github.com/tiangolo/fastapi/issues/3761
If you're not raising an HTTPException then normally any other uncaught exception will generate a 500 response (an Internal Server Error). If your intent is to respond with some other custom error message and HTTP status when raising a particular exception - say, ValueError - then you can use add a global exception handler to your app:
from fastapi import FastAPI, Request
from fastapi.responses import JSONResponse
#app.exception_handler(ValueError)
async def value_error_exception_handler(request: Request, exc: ValueError):
return JSONResponse(
status_code=400,
content={"message": str(exc)},
)
This will give a 400 response (or you can change the status code to whatever you like) like this:
{
"message": "Value Must be within range (0,1000000)"
}
Please note that pydantic expects that validators raise a ValueError, TypeError, or AssertionError (see docs) which pydantic will convert into a ValidationError.
Further, as per FastAPI's documentation:
When a request contains invalid data, FastAPI internally raises a RequestValidationError.
and
RequestValidationError is a sub-class of Pydantic's ValidationError.
The result of this is that a standard Validation error raised during pydantic's Model validation will be translated into a 422 Unprocessable Entity, and the response body will contain details on why the validation failed.
(As a side note: pydantic comes with constrained types which allow to constrain basic datatypes without having to write explicit validators.)
If the above is not satisfactory and you'd like to change the behaviour, here's how I would approach it (see here for details on the ValidationError handling):
from fastapi import Depends, FastAPI, Request, status
from fastapi.exceptions import RequestValidationError
from fastapi.exception_handlers import request_validation_exception_handler
from fastapi.responses import JSONResponse
from pydantic import BaseModel, conint
class RankInput(BaseModel):
# Constrained integer, must be greater than or equal to 0
# and less than or equal to 1 million.
rank: conint(ge=0, le=1_000_000)
async def rank_out_of_bound_handler(request: Request, exc: RequestValidationError):
validation_errors = exc.errors()
for err in validation_errors:
# You could check for other things here as well, e.g. the error type.
if "rank" in err["loc"]:
return JSONResponse(
status_code=status.HTTP_400_BAD_REQUEST,
content={"message": "Rank must be in range [0, 1000000]."}
)
# Default response in every other case.
return await request_validation_exception_handler(request, exc)
def get_info_by_rank(rank):
return rank
app = FastAPI(
exception_handlers={RequestValidationError: rank_out_of_bound_handler},
)
#app.get('/rank/{rank}')
async def get_rank(value: RankInput = Depends()):
result = get_info_by_rank(value.rank)
return result
A call to the endpoint now gives:
$ curl -i "http://127.0.0.1:8000/rank/1"
HTTP/1.1 200 OK
date: Sat, 28 Aug 2021 20:47:58 GMT
server: uvicorn
content-length: 1
content-type: application/json
1
$ curl -i "http://127.0.0.1:8000/rank/-1"
HTTP/1.1 400 Bad Request
date: Sat, 28 Aug 2021 20:48:24 GMT
server: uvicorn
content-length: 49
content-type: application/json
{"message":"Rank must be in range [0, 1000000]."}
$ curl -i "http://127.0.0.1:8000/rank/1000001"
HTTP/1.1 400 Bad Request
date: Sat, 28 Aug 2021 20:48:51 GMT
server: uvicorn
content-length: 49
content-type: application/json
{"message":"Rank must be in range [0, 1000000]."}
If you were to add a different endpoint that uses the same model, the exception handler will automatically take care of this as well, e.g.:
#app.get('/other-rank/{rank}')
async def get_other_rank(value: RankInput = Depends()):
result = get_info_by_rank(value.rank)
return result
$ curl -i "http://127.0.0.1:8000/other-rank/-1"
HTTP/1.1 400 Bad Request
date: Sat, 28 Aug 2021 20:54:16 GMT
server: uvicorn
content-length: 49
content-type: application/json
{"message":"Rank must be in range [0, 1000000]."}
If this is not what you're looking for, could you explain why exactly you'd like to raise a ValueError?
Related
So, Im doing simple todo-api app with fastapi and sqlmodel. Migrations went fine, but if I run my server, I dont see anything except empy array. I added some data in db file with DB Browser for SQLite, so it isn't empty.
And when I run my server and go to "/", I see only empty array and no data, and if I go to "/1/", I see this:
TypeError: Boolean value of this clause is not defined
My main.py:
from fastapi import FastAPI
import uvicorn
from endpoints.routers import router
from database.db import engine
from sqlmodel import SQLModel
app = FastAPI()
app.include_router(router)
# def create_db_and_tables():
# SQLModel.metadata.create_all(engine)
if __name__ == '__main__':
uvicorn.run("main:app", host='localhost', port=8000, reload=True)
# create_db_and_tables()
routers.py
from fastapi import APIRouter
from models.todo import ToDo
from repos.todo_repo import select_all_todos, select_todo
from database.db import session
from sqlmodel import Session, select
router = APIRouter()
#router.get("/", tags=['Todos'])
def show_todos():
todos = select_all_todos()
return todos
#router.get('/{id}/', response_model=ToDo, tags=['Todos'])
def select_one(id: int):
todo_found = select_todo(id)
return todo_found
repos:
from models.todo import ToDo
from sqlmodel import Session, select, or_
def select_all_todos():
with Session(engine) as session:
todos = select(ToDo)
results = session.exec(todos)
todo = results.all()
return todo
def select_todo(id):
with Session(engine) as session:
statement = select(ToDo)
statement = statement.where(ToDo.id==id)
if not statement:
return "Error"
result = session.exec(statement)
return result.first()
models:
from sqlmodel import Field, SQLModel
class ToDo(SQLModel, table=True):
id: Optional[int] = Field(default=None, primary_key=True)
name: str
is_done: bool = False
database.py file:
from sqlmodel import create_engine, Session
eng = 'database.db'
sqlite_url = f'sqlite:///{eng}'
engine = create_engine(sqlite_url, echo=True)
session = Session(bind=engine)
Traceback:
Traceback (most recent call last):
File "/home/aleksandr/Programming/Sites/myTodo/backend/venv/lib/python3.10/site-packages/uvicorn/protocols/http/h11_impl.py", line 407, in run_asgi
result = await app( # type: ignore[func-returns-value]
File "/home/aleksandr/Programming/Sites/myTodo/backend/venv/lib/python3.10/site-packages/uvicorn/middleware/proxy_headers.py", line 78, in __call__
return await self.app(scope, receive, send)
File "/home/aleksandr/Programming/Sites/myTodo/backend/venv/lib/python3.10/site-packages/fastapi/applications.py", line 270, in __call__
await super().__call__(scope, receive, send)
File "/home/aleksandr/Programming/Sites/myTodo/backend/venv/lib/python3.10/site-packages/starlette/applications.py", line 124, in __call__
await self.middleware_stack(scope, receive, send)
File "/home/aleksandr/Programming/Sites/myTodo/backend/venv/lib/python3.10/site-packages/starlette/middleware/errors.py", line 184, in __call__
raise exc
File "/home/aleksandr/Programming/Sites/myTodo/backend/venv/lib/python3.10/site-packages/starlette/middleware/errors.py", line 162, in __call__
await self.app(scope, receive, _send)
File "/home/aleksandr/Programming/Sites/myTodo/backend/venv/lib/python3.10/site-packages/starlette/middleware/exceptions.py", line 75, in __call__
raise exc
File "/home/aleksandr/Programming/Sites/myTodo/backend/venv/lib/python3.10/site-packages/starlette/middleware/exceptions.py", line 64, in __call__
await self.app(scope, receive, sender)
File "/home/aleksandr/Programming/Sites/myTodo/backend/venv/lib/python3.10/site-packages/fastapi/middleware/asyncexitstack.py", line 21, in __call__
raise e
File "/home/aleksandr/Programming/Sites/myTodo/backend/venv/lib/python3.10/site-packages/fastapi/middleware/asyncexitstack.py", line 18, in __call__
await self.app(scope, receive, send)
File "/home/aleksandr/Programming/Sites/myTodo/backend/venv/lib/python3.10/site-packages/starlette/routing.py", line 680, in __call__
await route.handle(scope, receive, send)
File "/home/aleksandr/Programming/Sites/myTodo/backend/venv/lib/python3.10/site-packages/starlette/routing.py", line 275, in handle
await self.app(scope, receive, send)
File "/home/aleksandr/Programming/Sites/myTodo/backend/venv/lib/python3.10/site-packages/starlette/routing.py", line 65, in app
response = await func(request)
File "/home/aleksandr/Programming/Sites/myTodo/backend/venv/lib/python3.10/site-packages/fastapi/routing.py", line 231, in app
raw_response = await run_endpoint_function(
File "/home/aleksandr/Programming/Sites/myTodo/backend/venv/lib/python3.10/site-packages/fastapi/routing.py", line 162, in run_endpoint_function
return await run_in_threadpool(dependant.call, **values)
File "/home/aleksandr/Programming/Sites/myTodo/backend/venv/lib/python3.10/site-packages/starlette/concurrency.py", line 41, in run_in_threadpool
return await anyio.to_thread.run_sync(func, *args)
File "/home/aleksandr/Programming/Sites/myTodo/backend/venv/lib/python3.10/site-packages/anyio/to_thread.py", line 31, in run_sync
return await get_asynclib().run_sync_in_worker_thread(
File "/home/aleksandr/Programming/Sites/myTodo/backend/venv/lib/python3.10/site-packages/anyio/_backends/_asyncio.py", line 937, in run_sync_in_worker_thread
return await future
File "/home/aleksandr/Programming/Sites/myTodo/backend/venv/lib/python3.10/site-packages/anyio/_backends/_asyncio.py", line 867, in run
result = context.run(func, *args)
File "/home/aleksandr/Programming/Sites/myTodo/backend/endpoints/routers.py", line 17, in select_one
todo_found = select_todo(id)
File "/home/aleksandr/Programming/Sites/myTodo/backend/repos/todo_repo.py", line 16, in select_todo
if not statement:
File "/home/aleksandr/Programming/Sites/myTodo/backend/venv/lib/python3.10/site-packages/sqlalchemy/sql/elements.py", line 590, in __bool__
raise TypeError("Boolean value of this clause is not defined")
TypeError: Boolean value of this clause is not defined
So, the exception is that you're not actually executing the statement in select_todo before checking for error. In SqlModel statement is a special kind of object to build and process a query, so it can't be directly checked for boolean value.
If you want to check if there are any results, place this statement under exec and check results instead.
There's no sense to check the statement itself in if, it's constructed successfully if no exception raised by that point
From reading the Traceback, I'd say that whatever type statement.where(ToDo.id==id) returns, seems not to have a __bool__() Magic Method defined. So you can't check for "truthy-ness" in the if statement.
I have a simple Flask application which calls FastApi with route /api,
FastAPI calls Postgresql Database.
Need to achieve 200 request/second (insertions through Flask => FastAPI => DB).
Flask
To run it I use gunicorn
gunicorn --worker-class gevent --workers 2 --threads 50 --bind 0.0.0.0:5000 main_api:app
from gevent import monkey
monkey.patch_all()
app = Flask(__name__)
#app.route('/api/mt_retailprice', methods=['POST'])
# #jwt_required()
def mt_retailprice():
try:
request_data = request.get_json()
_write_to_database(request_data)
return data
except Exception as e:
logging.error("Prediction is failed, review that json sent in the body is correct.Exception %s has happened", e)
return e
def _write_to_database(data):
api_url = f'http://127.0.0.1:3000/api/'
return write_sql(api_url, data)
def write_sql(url, data):
"""
Makes a POST request to a specific URL
"""
try:
headers = {
'Accept-Language': 'application/json',
'Content-Type': 'application/json'
}
payload = json.dumps(data)
return requests.post(url, headers=headers, data=payload)
except Exception as e:
logging.error(e)
def main():
configure_logging()
if __name__ == "__main__":
main()
FastAPI
class Database():
async def create_pool(self):
self.pool = await asyncpg.create_pool(user=username, password=password,
database=db_name, host=host, max_size=1000)
def create_app():
app = FastAPI()
db = Database()
#app.on_event("startup")
async def startup():
await db.create_pool()
#app.post('/api')
async def insert_db(request: Request):
data = ...
df = pd.DataFrame.from_dict(data)
tuples = [tuple(x) for x in df.values]
connection = await db.pool.acquire()
s = await connection.copy_records_to_table(table, schema_name=schema, records = tuples, columns = list(df.columns), timeout = 10)
return s
return app
app = create_app()
if __name__ == "__main__":
uvicorn.run(app, host="0.0.0.0", port=3000)
Here the logs from Apache Benchmark
$ ab -n 200 -c 20 -T "application/json" -p body.json http://127.0.0.1:5000/api/mt_retailprice
This is ApacheBench, Version 2.3 <$Revision: 1879490 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/
Benchmarking 127.0.0.1 (be patient)
Completed 100 requests
Completed 200 requests
Finished 200 requests
Server Software: gunicorn
Server Hostname: 127.0.0.1
Server Port: 5000
Document Path: /api/mt_retailprice
Document Length: 60 bytes
Concurrency Level: 20
Time taken for tests: 12.372 seconds
Complete requests: 200
Failed requests: 0
Total transferred: 42600 bytes
Total body sent: 137800
HTML transferred: 12000 bytes
Requests per second: 16.17 [#/sec] (mean)
Time per request: 1237.222 [ms] (mean)
Time per request: 61.861 [ms] (mean, across all concurrent requests)
Transfer rate: 3.36 [Kbytes/sec] received
10.88 kb/s sent
14.24 kb/s total
I have such error when make more requests. For example
ab -n 300 -c 20 -T "application/json" -p body.json
http://127.0.0.1:5000/api/mt_retailprice
Anyone know what's this error about ? can't find anything.
INFO: 127.0.0.1:50600 - "POST /api/
HTTP/1.1" 500 Internal Server Error
ERROR: Exception in ASGI application
Traceback (most recent call last):
File "/Users/dmitry/anaconda3/envs/nova/lib/python3.7/site-packages/uvicorn/protocols/http/httptools_impl.py", line 372, in run_asgi
result = await app(self.scope, self.receive, self.send)
File "/Users/dmitry/anaconda3/envs/nova/lib/python3.7/site-packages/uvicorn/middleware/proxy_headers.py", line 75, in __call__
return await self.app(scope, receive, send)
File "/Users/dmitry/anaconda3/envs/nova/lib/python3.7/site-packages/fastapi/applications.py", line 270, in __call__
await super().__call__(scope, receive, send)
File "/Users/dmitry/anaconda3/envs/nova/lib/python3.7/site-packages/starlette/applications.py", line 124, in __call__
await self.middleware_stack(scope, receive, send)
File "/Users/dmitry/anaconda3/envs/nova/lib/python3.7/site-packages/starlette/middleware/errors.py", line 184, in __call__
raise exc
File "/Users/dmitry/anaconda3/envs/nova/lib/python3.7/site-packages/starlette/middleware/errors.py", line 162, in __call__
await self.app(scope, receive, _send)
File "/Users/dmitry/anaconda3/envs/nova/lib/python3.7/site-packages/starlette/middleware/exceptions.py", line 75, in __call__
raise exc
File "/Users/dmitry/anaconda3/envs/nova/lib/python3.7/site-packages/starlette/middleware/exceptions.py", line 64, in __call__
await self.app(scope, receive, sender)
File "/Users/dmitry/anaconda3/envs/nova/lib/python3.7/site-packages/fastapi/middleware/asyncexitstack.py", line 21, in __call__
raise e
File "/Users/dmitry/anaconda3/envs/nova/lib/python3.7/site-packages/fastapi/middleware/asyncexitstack.py", line 18, in __call__
await self.app(scope, receive, send)
File "/Users/dmitry/anaconda3/envs/nova/lib/python3.7/site-packages/starlette/routing.py", line 680, in __call__
await route.handle(scope, receive, send)
File "/Users/dmitry/anaconda3/envs/nova/lib/python3.7/site-packages/starlette/routing.py", line 275, in handle
await self.app(scope, receive, send)
File "/Users/dmitry/anaconda3/envs/nova/lib/python3.7/site-packages/starlette/routing.py", line 65, in app
response = await func(request)
File "/Users/dmitry/anaconda3/envs/nova/lib/python3.7/site-packages/fastapi/routing.py", line 232, in app
dependant=dependant, values=values, is_coroutine=is_coroutine
File "/Users/dmitry/anaconda3/envs/nova/lib/python3.7/site-packages/fastapi/routing.py", line 160, in run_endpoint_function
return await dependant.call(**values)
File "app_test.py", line 49, in insert_db
connection = await db.pool.acquire()
File "/Users/dmitry/anaconda3/envs/nova/lib/python3.7/site-packages/asyncpg/pool.py", line 842, in _acquire
return await _acquire_impl()
File "/Users/dmitry/anaconda3/envs/nova/lib/python3.7/site-packages/asyncpg/pool.py", line 827, in _acquire_impl
proxy = await ch.acquire() # type: PoolConnectionProxy
File "/Users/dmitry/anaconda3/envs/nova/lib/python3.7/site-packages/asyncpg/pool.py", line 141, in acquire
await self.connect()
File "/Users/dmitry/anaconda3/envs/nova/lib/python3.7/site-packages/asyncpg/pool.py", line 133, in connect
self._con = await self._pool._get_new_connection()
File "/Users/dmitry/anaconda3/envs/nova/lib/python3.7/site-packages/asyncpg/pool.py", line 532, in _get_new_connection
record_class=self._record_class,
File "/Users/dmitry/anaconda3/envs/nova/lib/python3.7/site-packages/asyncpg/connect_utils.py", line 781, in _connect_addr
return await __connect_addr(params, timeout, True, *args)
File "/Users/dmitry/anaconda3/envs/nova/lib/python3.7/site-packages/asyncpg/connect_utils.py", line 833, in __connect_addr
tr, pr = await compat.wait_for(connector, timeout=timeout)
File "/Users/dmitry/anaconda3/envs/nova/lib/python3.7/site-packages/asyncpg/compat.py", line 66, in wait_for
return await asyncio.wait_for(fut, timeout)
File "/Users/dmitry/anaconda3/envs/nova/lib/python3.7/asyncio/tasks.py", line 442, in wait_for
return fut.result()
File "/Users/dmitry/anaconda3/envs/nova/lib/python3.7/site-packages/asyncpg/connect_utils.py", line 695, in _create_ssl_connection
host, port)
File "uvloop/loop.pyx", line 1978, in create_connection
socket.gaierror: [Errno 8] nodename nor servname provided, or not known
I have a FastAPI endpoint where it need to download some files from HDFS to the local server.
I'm trying to use asyncio to run the function that will download the files in a separate process.
I'm using FastAPI Depends to create a HDFS client and inject the object in the endpoint execution.
from fastapi import Depends, FastAPI, Request, Response, status
from hdfs import InsecureClient
import asyncio
from concurrent.futures.process import ProcessPoolExecutor
app = FastAPI()
HDFS_URLS = ['http://hdfs-srv.local:50070']
async def run_in_process(fn, *args):
loop = asyncio.get_event_loop()
return await loop.run_in_executor(app.state.executor, fn, *args) # wait and return result
def connectHDFS():
client = InsecureClient(url)
yield client
def fr(id, img, client):
# my code here
client.download(id_identifica_foto_dir_hdfs, id_identifica_foto_dir_local, True, n_threads=2)
# my code here
return jsonReturn
#app.post("/")
async def main(request: Request, hdfsclient: InsecureClient = Depends(connectHDFS)):
# Decode the received message
data = await request.json()
message = base64.b64decode(data['data']).decode('utf-8').replace("'", '"')
message = json.loads(message)
res = await run_in_process(fr, message['id'], message['img'], hdfsclient)
return {
"message": res
}
#app.on_event("startup")
async def on_startup():
app.state.executor = ProcessPoolExecutor()
#app.on_event("shutdown")
async def on_shutdown():
app.state.executor.shutdown()
But I'm not able to pass ahead the hdfsclient object:
res = await run_in_process(fr, message['id'], message['img'], hdfsclient)
I'm getting the following error:
Traceback (most recent call last):
File "/home/kleyson/.virtualenvs/reconhecimentofacial/lib/python3.7/site-packages/uvicorn/protocols/http/h11_impl.py", line 396, in run_asgi
result = await app(self.scope, self.receive, self.send)
File "/home/kleyson/.virtualenvs/reconhecimentofacial/lib/python3.7/site-packages/uvicorn/middleware/proxy_headers.py", line 45, in __call__
return await self.app(scope, receive, send)
File "/home/kleyson/.virtualenvs/reconhecimentofacial/lib/python3.7/site-packages/fastapi/applications.py", line 199, in __call__
await super().__call__(scope, receive, send)
File "/home/kleyson/.virtualenvs/reconhecimentofacial/lib/python3.7/site-packages/starlette/applications.py", line 111, in __call__
await self.middleware_stack(scope, receive, send)
File "/home/kleyson/.virtualenvs/reconhecimentofacial/lib/python3.7/site-packages/starlette/middleware/errors.py", line 181, in __call__
raise exc from None
File "/home/kleyson/.virtualenvs/reconhecimentofacial/lib/python3.7/site-packages/starlette/middleware/errors.py", line 159, in __call__
await self.app(scope, receive, _send)
File "/home/kleyson/.virtualenvs/reconhecimentofacial/lib/python3.7/site-packages/starlette/exceptions.py", line 82, in __call__
raise exc from None
File "/home/kleyson/.virtualenvs/reconhecimentofacial/lib/python3.7/site-packages/starlette/exceptions.py", line 71, in __call__
await self.app(scope, receive, sender)
File "/home/kleyson/.virtualenvs/reconhecimentofacial/lib/python3.7/site-packages/starlette/routing.py", line 566, in __call__
await route.handle(scope, receive, send)
File "/home/kleyson/.virtualenvs/reconhecimentofacial/lib/python3.7/site-packages/starlette/routing.py", line 227, in handle
await self.app(scope, receive, send)
File "/home/kleyson/.virtualenvs/reconhecimentofacial/lib/python3.7/site-packages/starlette/routing.py", line 41, in app
response = await func(request)
File "/home/kleyson/.virtualenvs/reconhecimentofacial/lib/python3.7/site-packages/fastapi/routing.py", line 202, in app
dependant=dependant, values=values, is_coroutine=is_coroutine
File "/home/kleyson/.virtualenvs/reconhecimentofacial/lib/python3.7/site-packages/fastapi/routing.py", line 148, in run_endpoint_function
return await dependant.call(**values)
File "./asgi.py", line 86, in main
res = await run_in_process(fr, message['id'], message['img'], hdfsclient)
File "./asgi.py", line 22, in run_in_process
return await loop.run_in_executor(app.state.executor, fn, *args) # wait and return result
File "/usr/lib/python3.7/multiprocessing/queues.py", line 236, in _feed
obj = _ForkingPickler.dumps(obj)
File "/usr/lib/python3.7/multiprocessing/reduction.py", line 51, in dumps
cls(buf, protocol).dump(obj)
TypeError: can't pickle _thread.lock objects
How can have the hdfsclient available inside the def fr() function without the need to create a new connection on every new request ? I mean, how to create the hdfsclient on the application startup and be able to use it inside the function ?
The entire point of asyncio is to do what you are trying to achieve in the same process.
The typical example is a web crawler, where you open multiple requests, within the same thread/process, and then wait for them to finish. This way, you will get data from multiple urls without having to wait each single request before starting the next one.
The same applies in your case: call your async function that downloads the file, do your stuff and then wait for the file download to complete (if it hasn't completed yet). Sharing data between processes is not trivial, and your function is not working because of that reason.
I suggest you to first understand what async is and how it works, before jumping into doing something that you don't understand.
Some tutorials on asyncio
https://www.datacamp.com/community/tutorials/asyncio-introduction
https://realpython.com/lessons/what-asyncio/
https://docs.python.org/3/library/asyncio.html
I want to host a pytorch model in a fastapi backend. When I run the code with python it is working fine. the depickled model can use the defined class. When the same file is started with uvicorn it cannot find the class definition.
Sourcecode looks like this:
import uvicorn
import json
from typing import List
from fastapi import Body, FastAPI
from fastapi.encoders import jsonable_encoder
import requests
from pydantic import BaseModel
#from model_ii import Model_II_b
import dill as pickle
import torch as T
import sys
app = FastAPI()
current_model = 'model_v2b_c2_small_ep15.pkl'
verbose_model = False # for model v2
class Model_II_b(T.nn.Module):
[...]
#app.post('/function')
def API_call(req_json: dict = Body(...)):
try:
# load model...
model = pickle.load(open('models/' + current_model, 'rb'))
result = model.dosomething_with(req_json)
return result
except Exception as e:
raise e
return {"error" : str(e)}
if __name__ == "__main__":
uvicorn.run(app, host="0.0.0.0", port=8000)
When I run this with python main.py it is working fine and I am gettings results. When I run it with uvicorn main:app and send a request I get the following error:
AttributeError: Can't get attribute 'Model_II_b' on <module '__mp_main__' from '/opt/webapp/env/bin/uvicorn'>
both should be using the same python env as I use the uvicorn from within the env.
I hope someone has an idea what is wrong with my setup or code.
Update Stacktrace:
(model_2) root#machinelearning-01:/opt/apps# uvicorn main:app --env-file /opt/apps/env/pyvenv.cfg --reload
INFO: Loading environment from '/opt/apps/env/pyvenv.cfg'
INFO: Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
INFO: Started reloader process [164777] using statreload
INFO: Started server process [164779]
INFO: Waiting for application startup.
INFO: Application startup complete.
INFO: 127.0.0.1:33872 - "POST /ml/v2/predict HTTP/1.1" 500 Internal Server Error
ERROR: Exception in ASGI application
Traceback (most recent call last):
File "/opt/apps/env/lib/python3.6/site-packages/uvicorn/protocols/http/httptools_impl.py", line 385, in run_asgi
result = await app(self.scope, self.receive, self.send)
File "/opt/apps/env/lib/python3.6/site-packages/uvicorn/middleware/proxy_headers.py", line 45, in __call__
return await self.app(scope, receive, send)
File "/opt/apps/env/lib/python3.6/site-packages/fastapi/applications.py", line 183, in __call__
await super().__call__(scope, receive, send) # pragma: no cover
File "/opt/apps/env/lib/python3.6/site-packages/starlette/applications.py", line 102, in __call__
await self.middleware_stack(scope, receive, send)
File "/opt/apps/env/lib/python3.6/site-packages/starlette/middleware/errors.py", line 181, in __call__
raise exc from None
File "/opt/apps/env/lib/python3.6/site-packages/starlette/middleware/errors.py", line 159, in __call__
await self.app(scope, receive, _send)
File "/opt/apps/env/lib/python3.6/site-packages/starlette/exceptions.py", line 82, in __call__
raise exc from None
File "/opt/apps/env/lib/python3.6/site-packages/starlette/exceptions.py", line 71, in __call__
await self.app(scope, receive, sender)
File "/opt/apps/env/lib/python3.6/site-packages/starlette/routing.py", line 550, in __call__
await route.handle(scope, receive, send)
File "/opt/apps/env/lib/python3.6/site-packages/starlette/routing.py", line 227, in handle
await self.app(scope, receive, send)
File "/opt/apps/env/lib/python3.6/site-packages/starlette/routing.py", line 41, in app
response = await func(request)
File "/opt/apps/env/lib/python3.6/site-packages/fastapi/routing.py", line 197, in app
dependant=dependant, values=values, is_coroutine=is_coroutine
File "/opt/apps/env/lib/python3.6/site-packages/fastapi/routing.py", line 149, in run_endpoint_function
return await run_in_threadpool(dependant.call, **values)
File "/opt/apps/env/lib/python3.6/site-packages/starlette/concurrency.py", line 34, in run_in_threadpool
return await loop.run_in_executor(None, func, *args)
File "/usr/lib/python3.6/concurrent/futures/thread.py", line 56, in run
result = self.fn(*self.args, **self.kwargs)
File "./main.py", line 155, in API_call
raise e
File "./main.py", line 129, in API_call
model = pickle.load(open('models/' + current_model, 'rb'))
File "/opt/apps/env/lib/python3.6/site-packages/dill/_dill.py", line 270, in load
return Unpickler(file, ignore=ignore, **kwds).load()
File "/opt/apps/env/lib/python3.6/site-packages/dill/_dill.py", line 473, in load
obj = StockUnpickler.load(self)
File "/opt/apps/env/lib/python3.6/site-packages/dill/_dill.py", line 463, in find_class
return StockUnpickler.find_class(self, module, name)
AttributeError: Can't get attribute 'Model_II_b' on <module '__mp_main__' from '/opt/apps/env/bin/uvicorn'>
enter code here
With the help from #lsabi I found the solution here https://stackoverflow.com/a/51397373/13947506
With the custom unpickler my problem was solved:
class CustomUnpickler(pickle.Unpickler):
def find_class(self, module, name):
if name == 'Model_II_b':
from model_ii_b import Model_II_b
return Model_II_b
return super().find_class(module, name)
current_model = 'model_v2b_c2_small_ep24.pkl'
model = CustomUnpickler(open('models/' + current_model, 'rb')).load()
I need to run a subprocess in my main process as "nobody" user, code like this:
# os.setuid(65534) # out the set_id work fine!!
logging.warning(f"outside user: {getpass.getuser()}")
# output: outside user: root
def set_id() -> None:
logging.warning(f"sub !sub! process user id is {os.getuid(), os.getgid(), os.getgroups()}!!!!!!!!!!!!")
# output: root:sub !sub! process user id is (0, 0, [])!!!!!!!!!!!!
assert os.getuid() == 0
logging.warning(f"inside user: {getpass.getuser()}")
# output: inside user: root
# os.setgid(65534) # work fine
os.setuid(65534) # can't work
pro = await asyncio.subprocess.create_subprocess_exec(
# *tmp_cmd,
"ls",
stdout=asyncio.subprocess.PIPE,
stdin=asyncio.subprocess.PIPE,
stderr=asyncio.subprocess.PIPE,
cwd=self._cwd,
preexec_fn=set_id,
start_new_session=True,
close_fds=True,
)
When I call os.setuid(65534), raise an error PermissionError: [Errno 13] Permission denied.
But os.setgid(65534) work fine.
Extra info:
Inside the set_id function, os.getuid(), os.getgid(), os.getgroups() 's out is
(0, 0, [])
Outside the set_id, os.setuid(65534) work fine.
getpass.getuser() == "root"
That's why? How can I fix this? Thanks in advance.
Traceback:
ERROR:uvicorn.error:Exception in ASGI application
Traceback (most recent call last):
File "/usr/local/lib/python3.7/dist-packages/uvicorn/protocols/websockets/websockets_impl.py", line 153, in run_asgi
result = await self.app(self.scope, self.asgi_receive, self.asgi_send)
File "/usr/local/lib/python3.7/dist-packages/uvicorn/middleware/proxy_headers.py", line 45, in __call__
return await self.app(scope, receive, send)
File "/usr/local/lib/python3.7/dist-packages/fastapi/applications.py", line 149, in __call__
await super().__call__(scope, receive, send)
File "/usr/local/lib/python3.7/dist-packages/starlette/applications.py", line 102, in __call__
await self.middleware_stack(scope, receive, send)
File "/usr/local/lib/python3.7/dist-packages/starlette/middleware/errors.py", line 146, in __call__
await self.app(scope, receive, send)
File "/usr/local/lib/python3.7/dist-packages/starlette/middleware/cors.py", line 68, in __call__
await self.app(scope, receive, send)
File "/usr/local/lib/python3.7/dist-packages/starlette/exceptions.py", line 58, in __call__
await self.app(scope, receive, send)
File "/usr/local/lib/python3.7/dist-packages/starlette/routing.py", line 550, in __call__
await route.handle(scope, receive, send)
File "/usr/local/lib/python3.7/dist-packages/starlette/routing.py", line 283, in handle
await self.app(scope, receive, send)
File "/usr/local/lib/python3.7/dist-packages/starlette/routing.py", line 57, in app
await func(session)
File "/usr/local/lib/python3.7/dist-packages/fastapi/routing.py", line 209, in app
await dependant.call(**values)
File "/opt/MakerServer/app/api/routes/websockets_runner/runner.py", line 21, in wss_back
process = await WSProcess.create(file_m, ws=websocket)
File "/opt/MakerServer/app/services/processer.py", line 100, in create
self.proc: asyncio.subprocess.Process = await self._create_sub_process() # type: ignore
File "/opt/MakerServer/app/services/processer.py", line 136, in _create_sub_process
close_fds=True,
File "/usr/lib/python3.7/asyncio/subprocess.py", line 217, in create_subprocess_exec
stderr=stderr, **kwds)
File "uvloop/loop.pyx", line 2749, in subprocess_exec
File "uvloop/loop.pyx", line 2707, in __subprocess_run
File "uvloop/handles/process.pyx", line 596, in uvloop.loop.UVProcessTransport.new
File "uvloop/handles/process.pyx", line 98, in uvloop.loop.UVProcess._init
PermissionError: [Errno 13] Permission denied
The question does not provide all the elements, but here is what I would see:
os.setuid cannot generate an errno of 13. A permission error from setuid would be EPERM, which is errno 1.
therefore, I believe it's not the os.setuid that generates the exception.
my guess would be that the exception is generated after your set_id function returns, when Popen tries to open some file as user 65534 (it could be the target executable, some library or some config file that gets loaded down the line).
How to proceed to solve this:
confirm the issue by adding a try catch block around os.setuid. I'm 99% sure it won't trigger.
then try to run your command from the shell with su as nobody user. Most likely you'll get the same error.
You can also use strace -f on your program to see which system call fails and what parameters it is invoked with. That should point you in the right direction.