utils.py 文件源码

def fix_s3_host(request, signature_version, region_name,
                default_endpoint_url='s3.amazonaws.com', **kwargs):
    """
    This handler looks at S3 requests just before they are signed.
    If there is a bucket name on the path (true for everything except
    ListAllBuckets) it checks to see if that bucket name conforms to
    the DNS naming conventions.  If it does, it alters the request to
    use ``virtual hosting`` style addressing rather than ``path-style``
    addressing.  This allows us to avoid 301 redirects for all
    bucket names that can be CNAME'd.
    """
    # By default we do not use virtual hosted style addressing when
    # signed with signature version 4.
    if signature_version is not botocore.UNSIGNED and \
            's3v4' in signature_version:
        return
    elif not _allowed_region(region_name):
        return
    try:
        switch_to_virtual_host_style(
            request, signature_version, default_endpoint_url)
    except InvalidDNSNameError as e:
        bucket_name = e.kwargs['bucket_name']
        logger.debug('Not changing URI, bucket is not DNS compatible: %s',
                     bucket_name)