Ability to use the CF Instance Identity-based CredHub roles

[46bit]

Right now authentication with CredHub is done with a specified UAA client. It would be awesome to have the option to use the mtls-app:APP_GUID role that is available by authenticating to CredHub with the instance identity cert/key on the app instance. This is less suitable for hand-configured CredHubs but will be much more useful for automated ones.

Will look at implementing this if GOV.UK PaaS go with CredHub 😄

[46bit]

P.S., Andy this is wonderful and I hope we'll be making heavy use of it alongside https://github.com/46bit/credhub-service-broker 🎉

[46bit]

From a deeper look, https://github.com/cloudfoundry-incubator/credhub-cli doesn't support for using mutual TLS client certificates despite that its underlying library does. That's frustrating and changing that is probably the starting point in fixing this.