Upload files from a multipart form directly to S3 (Falcon ASGI)

aioboto3_upload.py

import logging

import aioboto3
import falcon.asgi

logging.basicConfig(
    format='%(asctime)s [%(levelname)s] %(message)s', level=logging.INFO
)


class Upload:
    def __init__(self):
        self._session = aioboto3.Session()

    async def on_post(self, req, resp):
        form = await req.get_media()

        async with self._session.client(
            service_name='s3',
            aws_access_key_id='test:tester',
            aws_secret_access_key='testing',
            endpoint_url='http://localhost:8080',
        ) as s3:
            async for part in form:
                if part.filename:
                    await s3.upload_fileobj(
                        Bucket='bucket',
                        Key=f'uploads/{part.secure_filename}',
                        Fileobj=part.stream,
                    )


app = falcon.asgi.App()
app.add_route('/uploads', Upload())

This example assumes a Swift SAIO container running locally on port 8080.

Run the app with uvicorn:

pip install -U aioboto3 falcon s3cmd uvicorn[standard]
uvicorn aioboto3_upload:app

Create the example bucket as per https://hub.docker.com/r/openstackswift/saio:

s3cmd -c s3cfg_saio mb s3://bucket

Upload a file with curl:

curl -F file=@/my/file http://localhost:8000/uploads

Inspect the uploaded files

s3cmd -c s3cfg_saio ls s3://bucket/uploads/

Credits to @williamkibira for verifying this is possible (in a snippet posted on falconry/user).

May make sense linking this to the pr for future reference