Upload file gives body error with UploadFile

Description

I am having issues uploading a file to a FastAPI server. I found similar issues: #1367 and #405

However, there was no solution. The issue is that it works with small sized files, but when a file is bigger than 100Kb it does not work. It looks like the reading of the file does not finish before trying to run the other tasks like writing.

Code sample

import uvicorn
from fastapi import FastAPI, File, UploadFile
from fastapi.responses import FileResponse
import aiofiles

app = FastAPI(title='Untitled', description='doThings', version='0.0.1')

uploads = 'uploads'
uploads_dir = pathlib.Path(os.getcwd(), uploads)

@app.post('/api/upload/')
async def upload_file(file: UploadFile=File(...)):
    """
    Upload the file to be processed.
    """
    print(file)
#    async with aiofiles.open(file.file, 'rb') as fin:
#       exfile = fin.read() 
    file_name = pathlib.Path(uploads_dir, file.filename)
    async with aiofiles.open(f'{file_name}', 'wb') as f:
        await f.write(await file.read())
    return {'filename': file.filename, 
                    'content-type': file.content_type}

if __name__ == '__main__':
    uvicorn.run('main:app', host='127.0.0.1', port=5003, log_level='info')

Output

The error happens just when it tries to read the file. I have tried it only with the return and it does not work, neither. I have run many tests and I don’t get where the error comes.

This is the output of the uvicorn server:

INFO:     Started server process [7108]
INFO:     Waiting for application startup.
INFO:     Application startup complete.
INFO:     Uvicorn running on http://127.0.0.1:5003 (Press CTRL+C to quit)
INFO:     127.0.0.1:52854 - "POST /api/upload HTTP/1.1" 307 Temporary Redirect
Did not find boundary character 80 at index 2
INFO:     127.0.0.1:52855 - "POST /api/upload/ HTTP/1.1" 400 Bad Request
WARNING:  Invalid HTTP request received.

And in Postman I get this error message:

{
    "detail": "There was an error parsing the body"
}

Environment

OS: Windows 10 Python: Python 3.8.6 FastApi 0.61.2 Starlette 0.13.6 Pydantic 1.7.2

[llorencs]

Hello, following this, I have tested it directely with a requests snippet and it worked correctly. So, it can be closed.

[boun]

Sorry for commenting something totally unrelated to a closed bug, but google brought me here.

I had the same error, but did not use postman. In my case it was a kubernetes deployment. The solution was that the helm chart set the root fs to readonly.

Hope someone finds this helpful in the future.