How to limit Python FastAPI Post Request Upload File Size?-CodePudding

I am creating a FastAPI Python application where a user uploads a file to be processed. I do not want the file to exceed size X (in bytes).

How do I limit the file upload size before the POST request stores the file in memory?

I am using uivcorn for testing but I am expecting to deploy this code with google cloud platform (GCP). I am not sure if this can be done on the python code-side or server configuration-side.

Code Snippet:

from fastapi import (
     FastAPI, 
     Path, 
     File, 
     UploadFile, 
) 

app = FastAPI()

@app.post("/")
async def root(file: UploadFile  = File(...)):
     text = await file.read()
     text = text.decode("utf-8")
     return len(text)

CodePudding user response：

I found a python library that takes care of this via FastAPI middleware. If the upload file is too large it will throw a 413 HTTP error; "Error: Request Entity Too Large"

from starlette_validation_uploadfile import ValidateUploadFileMiddleware

 from fastapi import (
      FastAPI, 
      Path, 
      File, 
      UploadFile, 
 ) 


app = FastAPI()

#add this after FastAPI app is declared 
app.add_middleware(
        ValidateUploadFileMiddleware,
        app_path="/",
        max_size=1048576, #1Mbyte
        file_type=["text/plain"]
)


 @app.post("/")
 async def root(file: UploadFile  = File(...)):
      #...do something with the file
      return {"status: upload successful"}

CodePudding user response：

it usually controls by web server like nginx or Apache but if you want to control in the server side you can use this code:

from fastapi import (
    FastAPI,
    Path,
    File,
    UploadFile,
)

app = FastAPI()

@app.post("/")
async def root(file: UploadFile = File(...)):
    if len(await file.read()) >= 8388608:
        return {"Your file is more than 8MB"}