python - 如何使用 python 将文件上传到 Amazon S3 签名的 url？

Question

我已经成功地使用 boto3 生成了一个 Amazon S3 签名 URL。

import logging
import boto3
from botocore.exceptions import ClientError

def create_presigned_url(bucket_name, object_name, expiration=3600):
    """Generate a presigned URL to share an S3 object

    :param bucket_name: string
    :param object_name: string
    :param expiration: Time in seconds for the presigned URL to remain valid - 1 hour in this case
    :return: Presigned URL as string. If error, returns None.
    """

    # Generate a presigned URL for the S3 object
    s3_client = boto3.client('s3')
    try:
        response = s3_client.generate_presigned_url('get_object', Params={'Bucket': bucket_name, 'Key': object_name}, ExpiresIn=expiration)
    except ClientError as e:
        logging.error(e)
        return None

    # The response contains the presigned URL
    return response

result = create_presigned_url("bucket123", "test.txt")

假设 bucket123 存在。此代码返回如下 URL:

https://bucket123.s3.amazonaws.com/test.txt?AWSAccessKeyId=AKIA56EZ34KPFKO5366J&Signature=7aAZXXDwtvKGLaeu1ATHRJuaFCs%3D&Expires=1635117707

我的问题是:

使用 python 和 boto3，是否可以在此预签名 url 中上传文件？我该如何继续这件事？

Answer 1

一旦你有了预签名的 url，你就根本不需要 boto3。相反，您可以使用常规 python 函数将文件上传到 S3。例如使用 python 的 requests .你也应该使用 generate_presigned_post

def create_presigned_post(bucket_name, object_name,
                          fields=None, conditions=None, expiration=3600):
    """Generate a presigned URL S3 POST request to upload a file

    :param bucket_name: string
    :param object_name: string
    :param fields: Dictionary of prefilled form fields
    :param conditions: List of conditions to include in the policy
    :param expiration: Time in seconds for the presigned URL to remain valid
    :return: Dictionary with the following keys:
        url: URL to post to
        fields: Dictionary of form fields and values to submit with the POST
    :return: None if error.
    """

    # Generate a presigned S3 POST URL
    s3_client = boto3.client('s3')
    try:
        response = s3_client.generate_presigned_post(bucket_name,
                                                     object_name,
                                                     Fields=fields,
                                                     Conditions=conditions,
                                                     ExpiresIn=expiration)
    except ClientError as e:
        logging.error(e)
        return None

    # The response contains the presigned URL and required fields
    return response

result = create_presigned_post("bucket123", "test.txt")



import requests    # To install: pip install requests

# Generate a presigned S3 POST URL
object_name = 'test.txt'
result = create_presigned_post("marcin3", object_name)

# Demonstrate how another Python program can use the presigned URL to upload a file
with open(object_name, 'rb') as f:
    files = {'file': (object_name, f)}
    http_response = requests.post(result['url'], data=result['fields'], files=files)
# If successful, returns HTTP status code 204
logging.info(f'File upload HTTP status code: {http_response.status_code}')