The input prompts produced by Terraform itself are mainly there to help new Terraform users get started with an incomplete configuration, and aren’t really intended for ongoing use as a primarily workflow. As a result, the customization ability for those is very limited.
The recommended way to use the AWS provider for “real” use is to configure your credentials the same way as you would for the
aws CLI – commonly, using profiles in the credentials file as you’ve done here – and then use the standard AWS environment variables to either select a profile (using
AWS_PROFILE) or provide credentials directly (using
AWS_SECRET_ACCESS_KEY). In all such cases, Terraform should not produce any interactive prompts at all because it should be obtaining the required settings either directly from the configuration or in from the surrounding environment.
That way Terraform can be used in any context where the AWS CLI is properly configured, including non-interactive contexts like automation. Automation is a common end-state for organizations using Terraform in production, e.g. to ensure that an entire team can run Terraform in a consistent way in a single location, so I’d recommend constructing your system with that in mind even if you intend to run Terraform directly from a CLI prompt for now.