cdk.go: support --profile flag by adding missing provisioner

[waiteb3]

Overview

Fixes the cdk plugin not handling the --profile flag correctly when a profile is using role assumption. Now it matches the expected behavior of the aws plugin's --profile flag and the AWS_PROFILE environment variable.

Type of change

• Created a new plugin
• Improved an existing plugin
• Fixed a bug in an existing plugin
• Improved contributor utilities or experience

How To Test

If you have an existing CDK stack, you can confirm that using a profile to assume a role used for deployments.

cd $YOUR_CDK_DIR
cdk diff --profile cdk-stack-admin

Example ~/.aws/config file. Swap out with names and numbers from your account

[default]

[profile cdk-stack-admin]
source_profile=default
role_arn=arn:aws:iam::<AWS_ACC_NUM>:role/<CDK_ADMIN_ROLE>
role_session_name=cdk-stack-admin

Without the patch, the cdk will encounter the error below and fail

Need to perform AWS calls for account <AWS_ACC_NUM>, but no credentials have been configured

Changelog

AWS CDK Plugin now supports AWS Profiles that assume a role, when specified by the --plugin flag.

[SimonBarendse]

Security review approved

[AndyTitu]

Looks good to me functionally!