Hello, looks like java sdk doesn't support aws service authentication on a proxy. I have a proxy server with a iam role for s3 bucket access attached. When I use aws cli to access my s3 bucket via this proxy(HTTP_PROXY=http://proxy_host:proxy_port), it works. I don't have any credentials configured one the machine where I issue aws cli command. However, on same machine, using aws java sdk, I can't access s3 bucket via same proxy because aws java sdk requires a credentials. there doesn't seem to be any credential providers available for this scenario.

In a short:

• aws cli (no credentials -> proxy server (iam role configured) -> s3 -> SUCCESS
• aws java sdk (no credential) -> proxy server (iam role configured) -> s3 -> FAILURE (can't create client without credential)