How to get S3 bucket region.

[ShimYama]

If I want to get region of a bucket, I can use S3::S3Client::GetBucketLocation method.
But aws api reference says we should use HeadBucket method.

We recommend that you use HeadBucket to return the Region that a bucket resides in. For backward compatibility, Amazon S3 continues to support GetBucketLocation.

But S3::S3Client::HeadBucket method doesn't return any information about bucket region...

GetBucketLocation method has another problem. If the bucket region is 'us-east-1', the result of S3::S3Client::GetBucketLocation is NOT_SET. It sounds very strange...

Is there any smarter ways to get bucket region?

[jmklix]

It looks like this sdk isn't returning the headers when there is NoResult. The headers contain the region info that you are looking for. This is a bug, so we're looking into fixing this.

us-east-1 is special:

Buckets in Region us-east-1 have a LocationConstraint of null

This is expected behavior. I believe it is this way because all buckets used to not be associated to any region

[ShimYama]

Thank you for your answer.

It looks like this sdk isn't returning the headers when there is NoResult. The headers contain the region info that you are looking for. This is a bug, so we're looking into fixing

When the bug is fixed, should I use HeadBucket API rather than GetBucketLocation API that aws api reference reccomends?

us-east-1 is special:
Buckets in Region us-east-1 have a LocationConstraint of null
This is expected behavior. I believe it is this way because all buckets used to not be associated to any region

I understood.
However, using this method with Aws::S3::Model::BucketLocationConstraintMapper::GetNameForBucketLocationConstraint is a bit incovinient to me.

I wrote these source to find bucket location before upload and I have to write ridiculously long ternary operator line for us_east_1 exception...

Aws::S3::S3Client s3client;
Aws::S3::Model::GetBucketLocationRequest request;
request.SetBucket("<Some Bucket Name>");
Aws::String bucketLocationStr;

const auto outcome = s3client.GetBucketLocation(request);
if (outcome.IsSuccess()) {
   const auto location = outcome.GetResult().GetLocationConstraint();
   bucketLocationStr = Aws::S3::Model::BucketLocationConstraintMapper::GetNameForBucketLocationConstraint(location != Aws::S3::Model::BucketLocationConstraint::NOT_SET ? location : Aws::S3::Model::BucketLocationConstraint::us_east_1);
}

What do you think?

[fyse-nassar]

It looks like this sdk isn't returning the headers when there is NoResult. The headers contain the region info that you are looking for. This is a bug, so we're looking into fixing this.

@jmklix, is it fixed?

[sbiscigl]

this was fixed in 1.11.212 when we merged in customizations for express zonal one alongside other changes for re-invent last year. there are several important bug fixes related to it though so i would suggest picking up from HEAD. example code:

#include <aws/core/Aws.h>
#include <aws/core/utils/logging/LogLevel.h>
#include <aws/s3/S3Client.h>
#include <aws/s3/model/HeadBucketRequest.h>

using namespace Aws;
using namespace Aws::S3;
using namespace Aws::S3::Model;
using namespace Aws::Utils::Logging;

int main() {
    SDKOptions options;
    options.loggingOptions.logLevel = LogLevel::Debug;
    InitAPI(options);
    {
        S3Client client;
        const auto headBucket = client.HeadBucket(HeadBucketRequest().WithBucket("BucketName"));
        assert(headBucket.IsSuccess());
        std::cout << headBucket.GetResult().GetBucketRegion() << "\n";
    }
    ShutdownAPI(options);
    return 0;
}