Add Region in config.json file (#2570)

[ghost]

If not set in config.json, default is still us-east-1.

[codecov]

Codecov Report

Merging #2571 into master will decrease coverage by <.01%.
The diff coverage is 50%.

@@            Coverage Diff             @@
##           master    #2571      +/-   ##
==========================================
- Coverage   10.49%   10.49%   -0.01%     
==========================================
  Files         107      107              
  Lines       10828    10829       +1     
==========================================
  Hits         1136     1136              
- Misses       9542     9543       +1     
  Partials      150      150

Impacted Files	Coverage Δ
cmd/mb-main.go	0% <ø> (ø)	⬆️
cmd/config-v9.go	0% <ø> (ø)	⬆️
cmd/utils.go	29.65% <0%> (-0.18%)	⬇️
cmd/client-s3.go	13.38% <100%> (ø)	⬆️

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[vadmeste]

Hey @quentinselle, thanks for this PR.

The purpose of this PR is not clear for me yet, mc is supposed to calculate a bucket region automatically when applicable, are you targeting any specific use case ?

[ghost]

This PR is related to this issue #2570. If you have any questions, please feel free to ask.

[vadmeste]

This PR is related to this issue #2570. If you have any questions, please feel free to ask.

Listing buckets does not depend on region as @kannappanr mentioned, the region depends on the location of a bucket.

You can enable --debug flag in aws to see that it uses 'us-east-1' by default when region doesn't make sense in the current operation, (see StringToSign)

$ aws --debug s3 ls s3://
....
2018-10-22 17:07:39,629 - MainThread - botocore.auth - DEBUG - StringToSign:
AWS4-HMAC-SHA256                 
20181022T160739Z                
20181022/us-east-1/s3/aws4_request
....

[ghost]

Indeed, I discussed with @kannappanr on issue #2570 and we concluded that this Pull Request is useless. We found a better way to fix my problem (-> raise AuthorizationMalformed).

That's why I linked you the issue in the hope you'll read it and give a update to it before reply here (no reply on the issue since last week).

I now return a AuthorizationMalformed http error with the valid bucket region (<Region>$REGION</Region>) and I'm waiting for your reply (minio).

How do you suggest to implement the retry in minio-go ?
Could you please answer in the issue and close this Pull Request.

Thank you.

[poornas]

@quentinselle, minio-go already retries with region when response code is InvalidRegion. response message for AuthorizationHeaderMalformed needs to be parsed to get the correct region and set as errResp.region in https://github.com/minio/minio-go/blob/master/api-error-response.go#L179 and
https://github.com/minio/minio-go/blob/master/api.go#L630 to use the errResp.Region in case of AuthorizationHeaderMalformed

[kannappanr]

Closing this PR as suggested by @quentinselle