[openstack-dev] [ironic] Re: New API for node create, specifying initial provision state

Julia Kreger juliaashleykreger at gmail.com
Wed Aug 26 22:09:07 UTC 2015


My apologies for not expressing my thoughts on this matter
sooner, however I've had to spend some time collecting my
thoughts.

To me, it seems like we do not trust our users.  Granted,
when I say users, I mean administrators who likely know more
about the disposition and capabilities of their fleet than
could ever be discovered or inferred via software.

Sure, we have other users, mainly in the form of consumers,
asking Ironic for hardware to be deployed, but the driver for
adoption is who feels the least amount of pain.

API versioning aside, I have to ask the community, what is
more important?

- An inflexible workflow that forces an administrator to
always have a green field, and to step through a workflow
that we've dictated, which may not apply to their operational
scenario, ultimately driving them to write custom code to
inject "new" nodes into the database directly, which will
surely break from time to time, causing them to hate Ironic
and look for a different solution.

- A happy administrator that has the capabilities to do their
job (and thus manage the baremetal node wherever it is in the
operator's lifecycle) in an efficient fashion, thus causing
them to fall in love with Ironic.

To me, it seems like happy administrators are the most
important thing for us to focus on, and while the workflow
nature is extremely important for greenfield deployments,
the ability to override the workflow seems absolutely vital
to an existing deployment, even if it is via a "trust_me"
super secret advanced handshake of doom that tells the API
that the "user" know best.

As a consumer of Ironic, an administrator of sorts, I don't
care about API versions as much as much as it has been argued.
I care about being able to achieve a task to meet my goals in
an efficient and repeatable fashion. I want it to be easier
for an administrator to do their job.

-Julia


On Tue, Aug 18, 2015 at 8:05 PM, Ruby Loo <rlooyahoo at gmail.com> wrote:

>
>
>
>>> On 17 August 2015 at 20:20, Robert Collins <robertc at robertcollins.net>
>>> wrote:
>>>
>>>> On 11 August 2015 at 06:13, Ruby Loo <rlooyahoo at gmail.com> wrote:
>>>> > Hi, sorry for the delay. I vote no. I understand the rationale of
>>>> trying to
>>>> > do things so that we don't break our users but that's what the
>>>> versioning is
>>>> > meant for and more importantly -- I think adding the ENROLL state is
>>>> fairly
>>>> > important wrt the lifecycle of a node. I don't particularly want to
>>>> hide
>>>> > that and/or let folks opt out of it in the long term.
>>>> >
>>>> > From a reviewer point-of-view, my concern is me trying to remember
>>>> all the
>>>> > possible permutations/states etc that are possible to make sure that
>>>> new
>>>> > code doesn't break existing behavior. I haven't thought out whether
>>>> adding
>>>> > this new API would make that worse or not, but then, I don't really
>>>> want to
>>>> > have to think about it. So KISS as much as we can! :)
>>>>
>>>> I'm a little surprised by this, to be honest.
>>>>
>>>> Here's why: allowing the initial state to be chosen from
>>>> ENROLL/AVAILABLE from the latest version of the API is precisely as
>>>> complex as allowing two versions of the API {old, new} where old
>>>> creates nodes in  AVAILABLE and new creates nodes in ENROLL. The only
>>>> difference I can see is that eventually someday if {old} stops being
>>>> supported, then and only then we can go through the code and clean
>>>> things up.
>>>>
>>>> It seems to me that the costs to us of supporting graceful transitions
>>>> for users here are:
>>>>
>>>> 1) A new version NEWVER of the API that supports node state being one
>>>> of {not supplied, AVAILABLE, ENROLL}, on creation, defaulting to
>>>> AVAILABLE when not supplied.
>>>> 2) Supporting the initial state of AVAILABLE indefinitely rather than
>>>> just until we *delete* version 1.10.
>>>> 3) CD deployments that had rolled forward to 1.11 will need to add the
>>>> state parameter to their scripts to move forward to NEWVER.
>>>> 4) Don't default the client to the veresions between 1.10 and NEWVER
>>>> versions at any point.
>>>>
>>>> That seems like a very small price to pay on our side, and the
>>>> benefits for users are that they can opt into the new functionality
>>>> when they are ready.
>>>>
>>>> -Rob
>>>
>>>
> After thinking about this some more, I'm not actually going to address
> Rob's points above. What I want to do is go back and discuss... what do
> people think about having an API that allows the initial provision state to
> be specified, for a node that is created in Ironic. I'm assuming that
> enroll state exists :)
>
> Earlier today on IRC, Devananda mentioned that "there's a very strong case
> for allowing a node to be created in any of the stable states (enroll,
> manageable, available, active)". Maybe he'll elaborate later on this. I
> know that there's a use case where there is a desire to import nodes (with
> instances on them) from another system into ironic, and have them be active
> right away. (They don't want the nodes to go from
> enroll->verifying->manageable->cleaning!!!->available!!!->active).
>
> 1. What would the default provision state be, if it wasn't specified?
> A. 'available' to be backwards compatible with pre-v1.11
> or
> B. 'enroll' to be consistent with v1.11+
> or
> ?
>
>
> 2. What would it mean to set the initial provision state to something
> other than 'enroll'?
>
> manageable
> ----------------
> In our state machinery[0], a node goes from enroll -> verifying ->
> manageable. For manageble to be initial state, does it mean that
> A. whatever is needed for enroll and verifying is done and succeeds (under
> the hood)
> or
> B. whatever is needed for enroll is done and succeeds (but no verifying)
> or
> C. no enroll or verifying is done, it goes straight to manageble
>
> I'm fine with A.I'm not sure that B makes sense and I definitely don't
> think C makes sense. To date, verifying means checking that the conductor
> can get the power state on the node, to verify the supplied power
> credentials. I don't think it is a big deal if we skip this step; it just
> means that the next time some action is taken on the node, it might fail.
>
> available
> ------------
> In our state machinery, a node goes from enroll -> verifying -> manageable
> -> cleaning -> available. For available to be initial state, does it mean
> that
> A. whatever is needed for enroll, verifying, cleaning is done and succeeds
> (under the hood)
> or
> B. whatever is needed for enroll is done and succeeds (but no verifying or
> cleaning)
> or
> ??
>
> active
> --------
> In our state machinery, a node goes from enroll -> verifying -> manageable
> -> cleaning -> available->deploying->active. For active to be initial
> state, does it mean that
> A. whatever is needed for enroll, verifying, cleaning, deploying is done
> and succeeds (under the hood)
> or
> B. whatever is needed for enroll is done and succeeds (but no verifying or
> cleaning)
> or
> C. whatever is needed for enroll and I dunno, any 'takeover' stuff by
> conductor or whatever node states need to be updated to be in active?
>
> --ruby
>
> [0] http://docs.openstack.org/developer/ironic/dev/states.html
>
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