How can I enable CORS in FastAPI?

Question

I'm trying to enable CORS in this very basic FastAPI example, however it doesn't seem to be working.

from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware


app = FastAPI()

app.add_middleware(
    CORSMiddleware,
    allow_origins=['*']
)

@app.get('/')
def read_main():
    return {'message': 'Hello World!'}

This is the response I get:

curl -v http://127.0.0.1:8000
*   Trying 127.0.0.1...
* TCP_NODELAY set
* Connected to 127.0.0.1 (127.0.0.1) port 8000 (#0)
> GET / HTTP/1.1
> Host: 127.0.0.1:8000
> User-Agent: curl/7.64.1
> Accept: */*
>
< HTTP/1.1 200 OK
< date: Fri, 08 Jan 2021 19:27:37 GMT
< server: uvicorn
< content-length: 26
< content-type: application/json
<
* Connection #0 to host 127.0.0.1 left intact
{"message":"Hello World!"}*

Answer 1

等待大神答复