Google Cloud Storage Bucket 是否使用 Amazon S3？

Question

I did set up a Google Cloud Storage Bucket with index.html and test.html and what I see, when I go to my domain:

See: doc.s3.amazonaws.com/2006-03-01 in:

    <?xml version='1.0' encoding='UTF-8'?>
    <ListBucketResult xmlns='http://doc.s3.amazonaws.com/2006-03-01'> 
    <Name>my-domain.com</Name>
    <Prefix></Prefix>
    <Marker></Marker>
    <IsTruncated>false</IsTruncated>
    <Contents><Key>index.html</Key>
    <Generation>1555969892676799</Generation>
    <MetaGeneration>1</MetaGeneration>
    <LastModified>2019-04-22T21:51...</LastModified>
<ETag>"...."</ETag>
<Size>25</Size></Contents><Contents>
<Key>test.html</Key>

etc..

I do not have amazon account.

Answer 1

Despite that string being present in the namespace, the response to that request is not coming from AWS.

Google Cloud Storage (GCS) has two APIs. One is JSON-based and looks like most of Google's APIs (called the JSON API), and the other is XML-based and is designed to be interoperable with some cloud storage tools and libraries that work with S3. The idea is that, if you already use such a tool, such as the Python boto library, using GCS can be accomplished by changing the URL and credentials. Clients parsing XML responses likely validate XML namespaces, and so they expect to see something like the string " http://doc.s3.amazonaws.com/2006-03-01 " as part of the protocol.

You're sending a request to the XML API (either via storage.googleapis.com, BUCKET_NAME.storage.googleapis.com, or via a CNAME DNS redirect to Cloud Storage) , and so the resulting message tries to provide an interoperable response.

Answer 2

If we look at the documentation for the XML API found here we see that everything here is as expected. What we are seeing is an XML document which has an XML namespace called http://doc.s3.amazonaws.com/2006-03-01 . Think of this as a declaration of the usage of a named data type. It appears that this data type (a ListBucketResult ) was specified by AWS (Amazon) and GCP decided to re-use this specification in its own implementation rather than just implement a completely new specification which likely would have been semantically identical to that which already existed. The re-use of interfaces is normally a good thing for all. It would likely mean easier portability and less vendor lock-in to be able to choose a different cloud provider should you need.

I'm going to guess that AWS was the first to provide cloud blob storage and had set precedent. It is quite common to see XML Namespaces that describe open standards. I am going to also guess that there is no current open-standards specification for what a cloud storage provider should provide. So Amazon has S3, Google has Google Cloud Storage and Azure has Azure Blob Storage.