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#openstack-nova - 2023-12-12
16:45:33 sean-k-mooney well nova can do it
16:45:34 bauzas I mean, an admin doc
16:45:42 sean-k-mooney but we can have n upgade doc to cover how this works
16:46:10 sean-k-mooney i would hope its litrally just update the nova-compute binary adn restart the compute agent
16:46:15 bauzas sean-k-mooney: do you think of a nova-compute startup method that would check every single mdev and would persist it ?
16:46:15 sean-k-mooney no other upgrade impact
16:46:29 sean-k-mooney init host can reconsile what we expect based on teh current xmls
16:46:41 sean-k-mooney ya
16:46:45 sean-k-mooney that is what i was thinking
16:46:48 bauzas that's an additional effort, sure, still specless I think
16:46:57 sean-k-mooney we can defer that to impelmation review if we like
16:47:13 sean-k-mooney but i woudl ike to see upgrade in place support with or without a hard reboot i guess
16:47:15 bauzas sounds acceptable o me
16:47:37 bauzas we already have a broken method that's run on init_host
16:47:48 bauzas we could amend it to persist the mdev instead
16:48:12 bauzas (ie. delete and recreate it using libvirt API with the same uuid)
16:48:38 bauzas artom: does that sound reasonable to you ?
16:49:06 artom Sorry, reading back, in multiple places at the same time
16:49:28 bauzas IRC meetings are good, but people do many things at the same time :)
16:49:39 bauzas I wish we could be more in sync somehow :)
16:50:34 bauzas given we only have 10 mins left and anther procedural approval to do
16:50:41 bauzas lemme summarize
16:51:06 bauzas 1/ the feature will ensure that every new mdev to create will use the libvirt API
16:51:38 bauzas 2/ at compute restart, the implementation will check every mdev that's created and will recreate it using the libvirt API
16:52:11 artom OK, yeah, I think that makes sense, though the mechanics of persisting existing transient mdevs are less obvious to me at this time
16:52:25 bauzas 3/ documentation will address the fact that operator needs some cleanup (unpersisting the mdevs) in case they want to change the type, additional to the fact they need to drain vgpu instances from that host
16:52:38 sean-k-mooney i would hope its just generateing an xml and asking livbirt to create it
16:52:54 bauzas artom: don't be afraid, I exactly see what, where and how to do it
16:52:57 sean-k-mooney it should see that it already exist and i hope just write the mdevctl file
16:53:07 sean-k-mooney we can do this at the end of the seriese
16:53:12 sean-k-mooney to not blcoke the over all feature
16:53:32 bauzas based on those 3 bullet points, I don't see anything that requires a spec
16:53:37 bauzas anyone disagreeing ?
16:53:58 bauzas looks not
16:54:13 bauzas and as a reminder, a specless approval isn't a blank check about design
16:54:28 bauzas if something controversial comes up, we could revisit that and ask for a spec
16:54:34 bauzas based on that
16:54:40 gibi looks OK to me
16:54:54 bauzas #agreed https://blueprints.launchpad.net/nova/+spec/persistent-mdevs accepted as a specless blueprint
16:55:08 gibi Im not clear about when manual cleanup is needed but we can discuss that in the review
16:55:15 bauzas #action artom to amend the blueprint description to note what we agreed
16:55:24 bauzas moving on
16:55:32 bauzas I really want the last item to be discussed
16:55:37 bauzas (JayF/johnthetubaguy) Specless blueprint for ironic guest metadata
16:55:40 JayF o/
16:55:42 bauzas JayF: 'sup ?
16:55:48 JayF I am unsure if John will be here, but I am.
16:55:49 bauzas https://blueprints.launchpad.net/nova/+spec/ironic-guest-metadata
16:55:53 bauzas shot
16:55:57 bauzas shoot* even
16:56:44 sean-k-mooney reading it quickly it looks reasonable but i would use flavor uuid instead of name or both
16:56:59 bauzas ditto here
16:57:00 JayF Essentially, libvirt instances get a large amount of useful metadata that Ironic would like to get as well for various uses -- the primary case that drove us to this was implementing Ironic's "automatic_lessee" support, allowing Ironic to use the project that provisioned an instance some RBAC access to it
16:57:30 JayF but generally many of those metadata items map to previous feature requests / things that operators have asked for in node instance_info for troubleshooting in the past (like flavor)
16:57:33 bauzas I only care about the upgrade path
16:57:36 JayF so it seemed like a good fit/easy win
16:57:37 sean-k-mooney so i guess my request woudl be can we update the decription with the full list of things we want to be set
16:58:04 bauzas would we need some interim period to ensure all computes report that metadata ?
16:58:22 JayF Essentially this is just additional metadata you'd set on deploy
16:58:28 JayF it'd be Ironic's job to do the right thing if it's set/not set
16:58:30 sean-k-mooney so this is settign metadta on the ironic nodes right
16:58:32 sean-k-mooney not the compute nodes
16:58:34 JayF from a Nova standpoint, it should be 100% backwards compatible
16:58:41 sean-k-mooney as in when an instnace is shcudled ot a node
16:58:52 sean-k-mooney so for upgrade i guess we coudl have a nova-manage command
16:58:57 sean-k-mooney to set it for existing instnces
16:59:02 JayF oh, you mean for backfilling instance metadata, I understand
16:59:08 sean-k-mooney yep
16:59:10 JayF that's a case I hadn't even consideredd!
16:59:28 sean-k-mooney so i assume this would normally only be set on spawn
16:59:37 sean-k-mooney since ironci dose not support resize
16:59:45 sean-k-mooney well spawn or rebuild/evacuate
17:00:02 JayF Alright, looks like I have two actions: 1) List all the specific fields and 2) add details about migration path for preexisting instances and how/if they get metadata
17:00:08 JayF sean-k-mooney: we do rebuild, very common use case
17:00:19 sean-k-mooney ya so we would want to update it on rebuild right
17:00:33 sean-k-mooney so 3 actions. list the data to set, list when it will be set
17:00:39 bauzas sounds then an implementation detail to me
17:00:44 sean-k-mooney and then if we want to have a nova-manage command to backfile then detail that too
17:00:50 JayF yeah but one I don't mind enumerated in the blueprint to ensure I don't miss it
17:01:27 bauzas nova-manage what ? fill my ironic stuff for that instance ?
17:02:05 sean-k-mooney bauzas: ya set the metadtaa on the corresponding ironc node for an existing instance
17:02:19 bauzas couldn't it be some ironic script that would gather the details from the nova API ?
17:02:23 sean-k-mooney that shoudl be pretty simple to do its just a ironic api call
17:02:40 sean-k-mooney it could btu that feels liek a worse soultion to me
17:02:49 JayF So I'll note
17:02:52 bauzas sean-k-mooney: I'm not 100% happy with a very specific virt driver method in our nova-manage command
17:03:00 JayF From an Ironic standpoint, having the data backfilled is not super awesome
17:03:07 sean-k-mooney im pretty sure it woould not be the first
17:03:09 JayF we aren't going to do much with it
17:03:12 bauzas this would require nova-manage to be able to speak the ironic language
17:03:20 sean-k-mooney but this feels like the volume refesh commands to me
17:03:32 sean-k-mooney bauzas: it already can talk to ironci
17:03:33 JayF so while I'm happy to implement it, and I'm sure someone would find a use for it, I don't think it's in the primary path for enabling the sorta features we want
17:03:56 sean-k-mooney so i dont really mind where it ends up i guess but i think it woudl be nice to have
17:03:59 bauzas sean-k-mooney: creds and all the likes are set on nova.conf that nova-manage reads ?
17:04:30 JayF bauzas: you already have creds on nova-computes to do the calls you need
17:04:43 JayF PATCH calls to /v1/node/{UUID}
17:04:50 bauzas JayF: nova-manage isn't meant to be run on nova computes
17:04:55 JayF ack
17:05:15 sean-k-mooney bauzas: well its normally run on the contoler which often by acidnet is where nova-compute with ironic runs

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