aws/aws-cli — pull request #990 by jamesls (2014-11-07 17:16:40+00:00)
Title: Initial commit of assume role cred provider

This builds on the work of several existing
pull requests combining what I believe is
the combination of all the suggested changes
including:

* Use role_arn to trigger assume role behavior.
Do not require an explicit session to be created
and ended (#667).
* Cache the temporary credentials. If the credentials
are not expired then we should reuse them instead of
making the assume role call every time
(#656 and boto/botocore#226).

I think a strong case can be made to move this to botocore.
However, the file caching makes me somewhat hesitant to move
this into botocore (but I think the AssumeRoleProvider without
the caching could be added to botocore). I'd like to evaluate this in
the future but for now, I don't think it's unreasonable to leave
this in the AWS CLI for the time being. At any rate, this is
a straightforward and compatible move if we decide to do so.

Also, the ability to open a browser with the currently scoped
session has not been ported over. I'd like to address that
in a separate pull request.

cc @kyleknap @danielgtaylor