Assume IAM role script for AWS

As a user of an AWS account, use this zsh script to assume any given IAM role within the account.
Includes step of MFA authentication.

Usage

# Replace {role} with the ARN of the target IAM role. 
# Then run:
role_arn={role} source aws_assume_role.sh

Script will export AWS_ACCESS_KEY, AWS_SECRET_ACCESS_KEY and AWS_SESSION_TOKEN in the current shell.

Background

Further info on temporary security credentials can be found here.