[openstack-dev] [Ironic] Fuel agent proposal

Clint Byrum clint at fewbar.com
Tue Dec 9 18:34:24 UTC 2014

Excerpts from Yuriy Zveryanskyy's message of 2014-12-09 04:05:03 -0800:
> Good day Ironicers.
> I do not want to discuss questions like "Is feature X good for release 
> Y?" or "Is feature Z in Ironic scope or not?".
> I want to get an answer for this: Is Ironic a flexible, easy extendable 
> and user-oriented solution for deployment?

I surely hope it is.

> Yes, it is I think. IPA is the great software, but Fuel Agent proposes a 
> different and alternative way for deploying.

It's not fundamentally different, it is just capable of other things.

> Devananda wrote about "pets" and "cattle", and maybe some want to manage 
> "pets" rather than "cattle"? Let
> users do a choice.

IMO this is too high-level of a discussion for Ironic to get bogged
down in. Disks can have partitions and be hosted in RAID controllers,
and these things _MUST_ come before an OS is put on the disks, but after
power control happens. Since Ironic does put OS's on disks, and control
power, I believe it is obligated to provide an interface for rich disk

There are valid use cases for _both_ of those things in "cattle", which
is a higher level problem that should not cloud the low level interface

So IMO, Ironic needs to provide an interface for agents to richly
configure disks, whether IPA supports it or not.

Would I like to see these things in IPA so that there isn't a mismatch
of features? Yes. Does that matter _now_? Not really. The FuelAgent can
prove out the interface while the features migrate into IPA.

> We do not plan to change any Ironic API for the driver, internal or 
> external (as opposed to IPA, this was done for it).
> If there will be no one for Fuel Agent's driver support I think this 
> driver should be removed from Ironic tree (I heard
> this practice is used in Linux kernel).

We have a _hyperv_ driver in Nova.. I think we can have a "something
we're not entirely 100% on board with" in Ironic.

All of that said, I would admonish FuelAgent developers to work to
commit to combine their agent with IPA long term. I would admonish Ironic
developers to be receptive to things that users want. It doesn't always
mean taking responsibility for implementations, but you _do_ need to
consider the pain of not providing interfaces and of forcing people to
remain out of tree (remember when Ironic's driver wasn't in Nova's tree?)

More information about the OpenStack-dev mailing list