Is it possible for the TeamCity agents to assume the role, instead of the server?

[mendhak]

Thanks for writing the plugin. The README indicates,

the server assumes the requested role and sets AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY and AWS_SESSION_TOKEN environment variables for the build.

One potential problem is that a 'test deployment' could accidentally request credentials meant for a 'production deployment' and cause damage. So we're wondering if it'd be possible to have the agents request the credentials, or is this a limitation of TeamCity plugins?