How to check availability of AWS services in specific region

I'm provisioning an infrastructure in AWS using terraform by passing region as parameter. Under this infrastructure I'm spin up multiple EC2 instances and mount those with an EFS. I wanted to determine for which specific regions AWS offering EFS service so that I could write my script accordingly and provision an alternative solution for EFS at runtime where it's not supported.

I've googled and found describe-source-regions command through which I would determine the availability of service in particular region. But to execute this command I need to install aws-cli first at particular machine and provide AWS credentials. I just wanted to confirm that is there any over way to identify or have any better approach to get this information. This command returns such outputs.

    "FileSystems": []

if not supported

Could not connect to the endpoint URL: ""