Sign in with Google account?

In my ideal world, I'd create a group to allow my company's developers to have access to Kibana. Another group to allow only a fraction of them into production logs. All of that using their Google Account we already use pretty much in all SaaS we have.

When will Shield support "sign in with Google Account"?

Shield offers the ability to write your own realm. However, one possible issue may be the redirect to google for authentication as it is not possible for kibana to redirect a user right now based on the response returned from shield. In a future release we plan to add this functionality to kibana.