S3 Presigned url using boto3

presigned-upload-curl.sh

curl -v "https://mybucket.s3.amazonaws.com/"  \
-F "key=path/to/file.txt" \
-F "AWSAccessKeyId=access_key" \
-F "x-amz-security-token=security_token" \
-F "policy=base64_encoded_policy" \
-F "signature=signature" \
-F "file=@file.txt"

s3-presigned-url-response.json

{
  "url": "https://mybucket.s3.amazonaws.com/",
  "fields": {
    "key": "path/to/file.txt",
    "AWSAccessKeyId": "access_key",
    "x-amz-security-token": "security_token",
    "policy": "base64_encoded_policy",
    "signature": "signature"
  }
}

s3-presigned-url.py

import boto3

s3_client = boto3.client('s3', region_name='us-east-1')
resp = s3_client.generate_presigned_post("mybucket", "path/to/file.txt", ExpiresIn=600)
print(resp)