Planned change: disallow frameworks changing principals

[Greg Mann <gr...@mesosphere.io>]

Hi all,
Due to MESOS-2842 <https://issues.apache.org/jira/browse/MESOS-2842>, we
are planning to update the Mesos master to disallow frameworks from
changing their principal during reregistration. This will mean that over
the lifetime of a framework with a given framework ID, the framework will
only be able to use a single principal. Changing principals during
reregistration will currently cause the master to crash.

Furthermore, we persist framework principals in ReservationInfo and
DiskInfo in order to authorize UNRESERVE and DESTROY calls, so allowing the
framework to change its principal would interfere with authorization of
those actions.

If this change will cause any issues for you, please let us know. I've also
put this item on the agenda for tomorrow's API working group meeting at
11am PST; feel free to join and discuss!

Cheers,
Greg