POST with UploadFile returns 422 when called by client application #1911
Description
Example
import os
import shutil
from pathlib import Path
from tempfile import TemporaryDirectory
from fastapi import FastAPI, File, UploadFile
app = FastAPI()
def save_upload_file(upload_file: UploadFile, destination: Path) -> None:
# https://github.com/tiangolo/fastapi/issues/426#issuecomment-542828790
try:
with open(destination, "wb") as buffer:
shutil.copyfileobj(upload_file.file, buffer)
finally:
upload_file.file.close()
@app.post("/upload_two_files", summary="Upload and save two files")
def upload_sequences(
first_file: UploadFile = File(...),
second_file: UploadFile = File(...)
):
app_root = os.path.dirname(os.path.abspath(__file__))
upload_folder = os.path.join(app_root, 'upload-folder')
prefix = os.path.abspath(upload_folder)
temp_dir = TemporaryDirectory(prefix=prefix)
first_file_filename = first_file.filename
attributes_file_location = os.path.join(temp_dir.name, first_file_filename)
save_upload_file(first_file, first_file_file_location)
second_file_filename = second_file.filename
second_file_file_location = os.path.join(temp_dir.name, second_file_filename)
save_upload_file(second_file, second_file_file_location)
response = {"first_file": first_file_filename, "second_file": second_file_filename}
return responseDescription
I am trying to upload two files and process them.
It works from OpenAPI/Swagger UI (/docs) and from Postman with 'Content-Type: multipart/form-data'.
However, when a KNIME workflow I have inherited is making a call the code generates 422.
I have checked the KNIME node and it also contains 'Content-Type: multipart/form-data'. You can read more about the node here.
I have tried changing headers for the past few days and about to give up but would really prefer to keep FastAPI instead of turning back to Flask. I realize it's a very KNIME specific question but I would appreciate any advice at this point.
Environment
- OS: Linux
- FastAPI Version: 0.60.1
- Python version: 3.8
Additional context
Before I had this piece of Flask code which did work with the client code:
import os
from tempfile import TemporaryDirectory
from werkzeug.utils import secure_filename
from flask import Flask, request
app = Flask(__name__)
@app.route('/upload_two_files', methods=['POST'])
def upload_sequences():
first_file = request.files['first_file']
second_file = request.files['second_file']
app_root = os.path.dirname(os.path.abspath(__file__))
upload_folder = os.path.join(app_root, 'upload-folder')
prefix = os.path.abspath(upload_folder)
temp_dir = TemporaryDirectory(prefix=prefix)
first_file_filename = secure_filename(first_file.filename)
first_file_location = os.path.join(prefix, first_file_filename)
first_file.save(first_file_location)
second_file_filename = secure_filename(second_file.filename)
second_file_location = os.path.join(prefix, second_file_filename)
second_file_file.save(second_file_location)
response = {"first_file": first_file_filename, "second_file": second_file_filename}