I have a bunch of VPS's and every now and then I have to create another. Currently I use AWS, Rackspace and DigitalOcean as my IAAS providers. Most of them are Ubuntu-based. Besides, I have the users managed by Google Apps.
For each of the created VPS, I have to manage a root and a normal user, and multiple users must have access to the normal user credential. If a user is blocked (i.e. got fired..) he obviously should not have access to the VPS's anymore. Another must-have feature is to allow/block permissions by users group. The users group would be managed by Google Apps and the VPS's would only point to Google Apps authentication API or equivalent.
I want to know if there is such way of authenticating users in multiple VPS's using Google Credentials. This way, a user should do ssh john.doe@ to access the VPS, where john.doe is valid credential managed by Google Apps.
If there isn't, which is the recommended approach to my problem?