How to get an AWS bucket region from a bucket name for a private bucket through the API?-CodePudding

I'm interacting directly with the AWS API not through a language specific library.

I'm trying to call ListObjectsV2 on a bucket and getting back an error message:

<?xml version="1.0" encoding="UTF-8"?>
<Error>
    <Code>AuthorizationHeaderMalformed</Code>
    <Message>The authorization header is malformed; the region \'us-east-1\' is wrong; expecting \'eu-west-2\'</Message>
    <Region>eu-west-2</Region>
    <RequestId>3W75CR8BNRQJ13Y6</RequestId>
    <HostId>kYvjGFpckmTBxcq89h3Y dWmt7UrHJWXlOQyr0k9V2/07NJVDK4dwg2rqAayjOwV1P4Z5bFnvys=</HostId>
</Error>

This seems logical enough, I know the bucket I'm trying to interact with at the moment is eu-west-2.

My question is, if I didn't know a bucket's region, how could I find out through the API? Sigv4 requires you to specify the region, but if you don't know it, how can you construct a request to find out?

This is for private buckets. I've found answers for public bucets but they don't work for private buckets without authentication. And authentication requires you to know the region (AFAIK).

CodePudding user response：

There are three options.

For the first two, you can get the bucket region from the failure of a ListObjectsV2 call:

x-amz-bucket-region: us-west-2
x-amz-request-id: [...]
x-amz-id-2: [...]
Content-Type: application/xml
Transfer-Encoding: chunked
Date: Mon, 31 Oct 2022 14:42:37 GMT
Server: AmazonS3
Connection: close

<?xml version="1.0" encoding="UTF-8"?>
<Error>
  <Code>AuthorizationHeaderMalformed</Code>
  <Message>The authorization header is malformed; the region 'us-east-1' is wrong; expecting 'us-west-2'</Message>
  <Region>us-west-2</Region>
  <RequestId>...</RequestId>
  <HostId>...</HostId>
</Error>

You can pull out the bucket location from either the x-amz-bucket-region HTTP header in the response, or from the XML response in the Error.Region node.

Alternatively, you can place a HeadBucket call:

x-amz-id-2: ...
x-amz-request-id: ...
x-amz-bucket-region: us-west-2
x-amz-access-point-alias: false
Date: Fri, 10 2012 21:34:56 GMT
Server: AmazonS3

This includes the same x-amz-bucket-region header.

These are the same three ways in the same order, that BotoCore uses when access S3 APIs.

CodePudding user response：

The bucket information is on its edit page, there you can get the location information. And I had a problem with a script precisely because the aws-cli hadn't put the locale.