Open Stack

Magnum Team,

In the following review, we have the start of a discussion about how to tackle bay status:

https://review.openstack.org/159546

I think a key issue here is that we are not subscribing to an event feed from Heat to tell us about each state transition, so we have a low degree of confidence that our state will match the actual state of the stack in real-time. At best, we have an eventually consistent state for Bay following a bay creation.

Here are some options for us to consider to solve this:

1) Propose enhancements to Heat (or learn about existing features) to emit a set of notifications upon state changes to stack resources so the state can be mirrored in the Bay resource.

2) Spawn a task to poll the Heat stack resource for state changes, and express them in the Bay status, and allow that task to exit once the stack reaches its terminal (completed) state.

3) Don’t store any state in the Bay object, and simply query the heat stack for status as needed.

Are each of these options viable? Are there other options to consider? What are the pro/con arguments for each?

Thanks,

Adrian