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#openstack-nova - 2024-01-31
14:00:38 bauzas that's my concern
14:00:45 sean-k-mooney but doing only in perodic woudl not be ok in my view
14:00:54 bauzas I don't want the delete to have an exception if we are not able to call Manila
14:01:12 gibi what happens today when a volume cannot be detached during VM delete?
14:01:18 bauzas we should rather delete the guest and eventually try to unmount
14:01:35 sean-k-mooney no the unmount on the host has to happen as part of the delete
14:01:41 sean-k-mooney its a security isssue if it does not
14:01:49 bauzas why ?
14:01:51 sean-k-mooney the unlock of the share could be defered
14:02:06 sean-k-mooney bauzas: because you have a tenatns data volume present on the host
14:02:15 bauzas if we don't delete the share in nova, it's just a file
14:02:22 bauzas that none of other instances could use
14:02:56 sean-k-mooney its not just a file its an nfs/cephfs share that is mounted on the host
14:03:09 sean-k-mooney that anyoen with host access coudl read with the correct permissions
14:03:32 bauzas anyone with host access would have more possibilties than using a share
14:03:38 sean-k-mooney i.e. if you break out of a vm and get host access you can read the shares for any share mounted on the host
14:04:02 sean-k-mooney sure, to gibi's point we should mirror what we do for cinder volumes
14:04:12 bauzas I think we said that it's not a security issue if you need to ssh to the host
14:04:43 bauzas the problem we had with cinder is that we were able to get *that* bdm for other instances
14:04:52 sean-k-mooney this is very close but not the same as the cidner issue with deleting the atatchment in my view
14:05:09 bauzas we discussed that a bit this morning during our meeting
14:05:12 sean-k-mooney bauzas: not bdm, host block device
14:05:21 bauzas correct
14:05:36 bauzas anyway, I'm doing other things by now, I can't discuss it more now
14:05:42 sean-k-mooney ya so i agree you wont have sharing because we will be mounting the sahre under the instance dir right
14:05:44 bauzas Uggla: are you OK ?
14:06:09 bauzas no, we don't mount the share on the instance dir
14:06:31 bauzas but we have share mappings telling which share to use with what instance
14:06:33 sean-k-mooney it should be either configurabel or under the instace dir
14:06:45 bauzas there is a spec
14:06:53 bauzas and within this spec, this is explained
14:07:01 Uggla bauzas, yep for me it is ok. I have my answers
14:07:15 sean-k-mooney bauzas: im pretty sure the spec did not say its oke to defer the unmoutn to a perodic
14:08:31 bauzas that, indeed, I was just saying about the share path
14:08:53 bauzas anyway, /me going back to work given Uggla got his answers
14:09:33 sean-k-mooney Uggla: so your going to do the unmount when deleting the isntance as part of delete with a fallback to a perodic
14:10:08 sean-k-mooney and not have manilla block the delete if unlocking fails?
14:10:08 Uggla sean-k-mooney, yep but atm I have not periodic.
14:10:39 sean-k-mooney right so without that we would have to make the failure to unlock put the instnace in error
14:10:49 sean-k-mooney gibi: how do you feel about that ^
14:12:48 sean-k-mooney i do not have the full context so im mostly relying on you adn bauzas to ensure the correct behavior. if we just ignroed the failure to unlock the manilla share with no recovery method i woudl think that deserves a -2
14:14:59 gibi The cheaper way is to put the instance in ERROR during delete. I suggest to check what we do with cinder volumes during delete if cinder is unavailable
14:15:08 sean-k-mooney we need to be careful of two things: 1.) we are not locking the share indefintly if we delete the isntnce and the manial call fails, that has billing implciations. 2.) we are not exporting the sahre to host it shoudl not be on, the has security implcitations, and possible regelarotry complicne issues.
14:15:34 gibi I agree about these goals ^^
14:16:21 sean-k-mooney i would have been ok with puting the instnace in error
14:16:28 sean-k-mooney so you can just try again
14:16:33 sean-k-mooney when manilla is fixed
14:17:07 sean-k-mooney and i suspect that is what would happen for a BFV guest with delete on terminate but im not sure
14:18:08 sean-k-mooney it looks like in terminate we do self._cleanup_volumes(context, instance, bdms,
14:18:10 sean-k-mooney raise_exc=False, detach=False)
14:18:59 sean-k-mooney that imples we allwo the delete to proceed
14:19:18 bauzas I also agree with the two bullet points (just lurking)
14:20:30 bauzas tbh, I don't really like us copying the cinder workflow
14:20:36 sean-k-mooney i am about to enter 3 hours of meetings in 3.5 hours
14:20:45 bauzas recent issues led me think there are some corner cases I'd like to avoid :)
14:20:47 sean-k-mooney so ill also be "steppign way shortly"
14:21:18 bauzas but agreed on the
14:21:23 sean-k-mooney right i think gibi and i wourl prefer to be stircter and fail the delte
14:21:25 bauzas DONTs and the DOES
14:21:50 sean-k-mooney but lets loop back to this after Uggla has updated things
14:21:53 sean-k-mooney and we have more time
14:22:05 bauzas I think we said we should never try to fail on an instance delete
14:22:15 bauzas as there are also some capacity and billing implications
14:22:25 sean-k-mooney we can fail on isntance delete for other reasons im pretty sure
14:22:45 sean-k-mooney but you are correct on the capsity and billing implciations if we do too
14:22:55 gibi it is a trade off if we let the VM delete to happen but leak resources in the meantime you still get billing issues :D
14:23:12 bauzas as an operator, I'd be more angry if my instance would continue to exist because of a cheap open file not deleted
14:23:37 bauzas but I could be wrong
14:23:50 gibi bauzas: e.g. we delete your VM happily but fail to unlock the share in manila. So you are billed for a share you cannot use :)
14:24:03 bauzas hence the periodic :)
14:24:27 gibi which can be turned off :
14:24:28 gibi :)
14:24:34 bauzas I'm not saying we should leave the pipe leaking
14:24:53 bauzas what I'm saying is that there are bigger things to do than fixing the pipe
14:24:54 sean-k-mooney bauzas: would that same operator be ok if custoemr data was leaked via presitent memroy, or if vgpus were never made avaiable again or pci devices
14:24:58 gibi at least if my VM is in ERROR and I cannot delete it I will notice and raise a ticket
14:25:18 sean-k-mooney so there is a way to fix this
14:25:40 sean-k-mooney we coudl ask manilla to aloow the share delteion if the nova instnace nolonger exists
14:25:56 sean-k-mooney that coudl be a followup enhacnment on there side
14:26:24 sean-k-mooney so if its locked by nova but nova says the isntnace is gone aloow the user to delelete it even with the lock
14:26:31 bauzas gibi: sean-k-mooney: standing as a user for a sec,
14:26:42 bauzas if I delete my instance and it goes into ERROR
14:26:53 bauzas the second after, I'm gonna try to delete again
14:27:01 sean-k-mooney yep which might work
14:27:01 bauzas so I could be okay
14:27:04 gibi :)
14:27:21 bauzas provided we ensure that the instance deletion path is idempotent
14:27:38 sean-k-mooney yes but we already need to do that
14:28:05 sean-k-mooney i belive one path where instance delete ends with an instance in error
14:28:10 sean-k-mooney is if the connection to libvirt is down
14:29:23 sean-k-mooney or ironic/hyperv/vmware api is not accable
14:29:45 sean-k-mooney assuming the comptue agent is fine it will have to put it in error when it cant talk to the hypervior
14:30:00 sean-k-mooney well that or leave the instnace in active
14:30:05 sean-k-mooney and put the instnace action in errror
14:30:21 sean-k-mooney ok meetings starting
15:11:52 bauzas every time I'm trying to pull a devstack on a RHEL machine, I'm getting funny stories
15:24:58 bauzas Failed to discover available identity versions when contacting http://10.73.116.68/identity. Attempting to parse version from URL.
15:24:58 bauzas Could not find versioned identity endpoints when attempting to authenticate. Please check that your auth_url is correct. Service Unavailable (HTTP 503)
15:25:15 bauzas but when looking at keystone logs in the journal, lgtm
15:25:31 bauzas wtf...

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