The http body stream is not a seekable stream, so most operation
retry attempts will fail with an internal server error. This
change tells the s3 client within the gateway to not retry any
requests, and instead let the client of the gateway handle the
error retry.
Fixes#1353
The previous way of initializing the s3 client in each call was
adding a lot of overhead and would tank performance beyond about
20 simultaneous requests.
Since the backend access is through a single account, we can init
and store this client for use from each api call.
This backend redirects incoming requests to another s3 service.
This will use the incoming credentials to setup the client
requests to the external s3 service. So the IAM accounts (or
root account) must match what the external s3 service expects.
