How to recover error of specify a region when commend runs aws ecs list-container-instances
Utilize this command in the AWS CLI:
AWS ecs list-container-instances --cluster default --region us-east-1
>> utilize your region (http://docs.aws.amazon.com/general/latest/gr/rande.html)
Or on the other hand, you can utilize this to give the region:
send out botocore.exceptions.noregionerror: you must specify a region