AWS_ACCESS_KEY_ID and AWS_ACCESS_KEY_SECRET
Specify the "AWS Access Key Identifiers" for the AWS account. AWS_ACCESS_KEY_ID contains the "Access Key ID", and AWS_ACCESS_KEY_SECRET contains the "Secret Access Key". These are effectively the "username" and "password" to the AWS service, and should be kept confidential.
The access keys MUST be specified, either via these environment variables, or via the --access-key and --secret-key command line parameters.
If the command line parameters are set, they override these environment variables.