This works but will be migrated in to a different package (possibly aaronland/go-aws-session) soon.
aws-mfa-session
$> ./bin/aws-mfa-session -h
Usage of ./bin/aws-mfa-session:
-duration string
A valid ISO8601 duration string indicating how long the session should last (months are currently not supported) (default "PT1H")
-profile string
A valid AWS credentials profile (default "default")
-session-profile string
The name of the AWS credentials profile to update with session credentials (default "session")
For example:
$> ./bin/aws-mfa-session -profile {PROFILE} -duration PT8H
Enter your MFA token code: 123456
2018/07/26 09:47:09 Updated session credentials for 'session' profile, expires Jul 26 17:47:09 (2018-07-27 00:51:52 +0000 UTC)