I have an IAM user in account A with keys set up (xxx) and I wish to access a bucket in account B. On the aws cli, I can run AWS_ACCESS_KEY_ID=xxx AWS_SECRET_ACCESS_KEY=xxx aws s3api head-bucket --bucket account-b-bucket (and list objects, etc) and it works just fine (I set up a bucket policy and proper iam policy, so this is expected).
I have a minio server running with those access keys passed as minion access keys. If I start up the minio client (I use python) and run client.bucket_exists("some-bucket-in-account-a") it works. However, client.bucket_exists("account-b-bucket") returns False.
I tried this out for buckets in both us-east-1 and us-west-2, and it does not work.
What else is required for minio to access a bucket in another aws account?
Note that I start my minio client with the endpoint of s3.amazonaws.com it does work, but I want to point the minio client to my running minio instance like my-minio.my-site.com.