Keep getting "307 Temporary Redirect" before returning status 200 hosted on FastAPI + uvicorn + Docker app - how to return status 200?

Question

Edit:

I found the problem but not sure why this happens. Whenever I query: http://localhost:4001/hello/ with the "/" in the end - I get a proper 200 status response. I do not understand why.

Original Post:

Whenever I send a query to my app - I keep getting a 307 redirect. How to get my app to return regular status 200 instead of redirecting it through 307

This is the request output:

abm                  | INFO:     172.18.0.1:46476 - "POST /hello HTTP/1.1" 307 Temporary Redirect
abm                  | returns the apples data. nothing special here.
abm                  | INFO:     172.18.0.1:46480 - "POST /hello/ HTTP/1.1" 200 OK

pytest returns:

E       assert 307 == 200
E        +  where 307 = <Response [307]>.status_code

test_main.py:24: AssertionError

in my root dir: /__init__.py file:

from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware
# from .configs import cors
from .subapp import router_hello
from .potato import router_potato
from .apple import router_apple


abm = FastAPI(
    title = "ABM"
)

# potato.add_middleware(cors)
abm.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

abm.include_router(router_hello.router)
abm.include_router(router_potato.router)
abm.include_router(router_apple.router)

@abm.post("/test", status_code = 200)
def test():
    print('test')
    return 'test'

/subapp/router_hello.py file:

router = APIRouter(
    prefix='/hello',
    tags=['hello'],
)

@router.post("/", status_code = 200)
def hello(req: helloBase, apple: appleHeader = Depends(set_apple_header), db: Session = Depends(get_db)) -> helloResponse:
    db_apple = apple_create(apple, db, req.name)
    if db_apple:
        return set_hello_res(db_apple.potato.api, db_apple.name, 1)
    else:
        return "null"

in /Dockerfile:

CMD ["uvicorn", "abm:abm", "--reload", "--proxy-headers", "--host", "0.0.0.0", "--port", "4001", "--forwarded-allow-ips", "*", "--log-level", "debug"]

I tried with and without "--forwarded-allow-ips", "*" part.

Answer 1

It happens because the exact path defined by you for your view is yourdomainname/hello/, so when you hit it without / at the end, it first attempts to get to that path but as it is not available it checks again after appending / and gives a redirect status code 307 and then when it finds the actual path it returns the status code that is defined in the function/view linked with that path, i.e status code 200 in your case.

You can also read more about the issue here: https://github.com/tiangolo/fastapi/issues/2060#issuecomment-834868906