如何获取桶区域并将其传递给客户端o生成预先签名的URLS s3

Question

我有这段代码来为最近匹配字符串的对象生成预先签名的URL。

问题是，在生成url的同时，如何将正确的区域传递给s3客户机，如果它没有生成正确的URL，则这段代码是没有用的。

#! /usr/bin/python
#This script generates S3 object pre-signed URL

import logging
import boto3
from botocore.exceptions import ClientError

def keys(bucket_name, prefix="", delimiter="/"):
    """Generate a key listings
    :param bucket_name: string
    :param prefix: string
    :param delimiter: string
    """
    for page in (
        boto3.client("s3")
        .get_paginator("list_objects_v2")
        .paginate(
            Bucket=bucket_name,
            Prefix=prefix[len(delimiter) :] if prefix.startswith(delimiter) else prefix,
            **{"StartAfter": prefix} if prefix.endswith(delimiter) else {}
        )
    ):
        for content in page.get("Contents", ()):
            yield content["Key"]

def latest(bucket_name, prefix):
    """Generate a latest logfile
    :param bucket_name: string
    :param prefix: string
    :return: Object keys
    """
    return(max(i for i in keys(bucket_name) if prefix in i))

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
    :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

print(create_presigned_url("database-backup", latest("database-backup", "my-backup")))```

Answer 1

优化@john的答案。

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
    :return: Presigned URL as string. If error, returns None.
    """

    # Generate a presigned URL for the S3 object
    s3_client = boto3.session.Session(
        region_name=boto3.client('s3').get_bucket_location(Bucket=bucket_name)["LocationConstraint"]
    ).client("s3")

Answer 2

在@wpp的回答上展开，您的代码如下所示：

def create_presigned_url(bucket_name, object_name, expiration=3600):

    # Get region for bucket
    s3_client = boto3.client('s3')
    response = s3_client.get_bucket_location(Bucket=bucket_name)

    # Generate a presigned URL for the S3 object
    s3_client = boto3.client('s3', region_name=response['LocationConstraint'])
    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

Answer 3

为了得到桶的区域，使用get_bucket_location()方法的S3客户端。

您可能需要在此区域创建boto3会话，然后从该会话创建客户端。