presigned_s3_upload.py

#!/usr/bin/env python3
# Get file path from sys.argv and upload as a presigned URL

import os
import sys
import boto3
import requests

asset_path = sys.argv[1]
_, asset_fname = os.path.split(asset_path)
bucket_name = 'BUCKET_NAME'

ctype = 'image/jpg'
url_lifetime = '3600'
s3_client = boto3.client('s3')
upload_url = s3_client.generate_presigned_url(
    'put_object',
    Params={
        'Bucket': bucket_name,
        'Key': asset_path,
        'ContentType': ctype,
    },
    ExpiresIn=url_lifetime,
)

headers = {"Content-Type": ctype}
data = open(asset_path, 'br')
print('{} {}'.format(os.path.getsize(asset_path), asset_path))
try:
    resp = requests.put(upload_url, headers=headers, data=data)
except Exception as e:
    print("EXCEPTION: {}".format(e))

I wrote this to test the limits of presigned S3 URL uploads: it's 5.0GiB, which I only found much later in AWS docs about limits of PUT.