Consolidation with spot by default is not appropriate

[leoryu]

Description

Observed Behavior:

From :

https://github.com/kubernetes-sigs/karpenter/blob/372b9c82eeb86efd7bbb1bbba0b55f230ab65c98/pkg/controllers/disruption/consolidation.go#L192-L205

Karpenter will set nodeclaim's CapacityType with spot if reqs allow CapacityType with [OD, spot].

This logic will let karpenter always creates spot machine, even the cheapest machine is OD but not the spot one.

And the worst case is that there is no spot machine avaliabel, the karpenter wiill report err:

logger":"controller","message":"failed launching nodeclaim","controller":"nodeclaim.lifecycle","controllerGroup":"karpenter.sh","controllerKind":"NodeClaim","NodeClaim": ...

Since the created nodeclaim has reqs with 'spot', the consolidation will not sucess even we have cheaper OD machine.

Expected Behavior:

What I expected in consolidation is that:

Do not modify the CapacityType, just choose the chpeast machine if my reqs has ignore the capacity type.

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[k8s-ci-robot]

This issue is currently awaiting triage.

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[leoryu]

@njtran Hi, I found the code is commit by you 2 yeases ago. Could you explain why nodeclaim is always spot in consolidation? Since the real world spot machine might not be available, I think karpenter should choose the cheapeast one, even the machine is on-demand.