fix: Fix panic in termination flow

[jonathan-innis]

Fixes #

Description

• Termination could panic with the following error when the Patch() update results in the apiserver immediately return back an object that doesn't contain a deletionTimestamp set inside of it (because the object was quickly removed)

2023-02-06T21:35:18.371Z	INFO	controller	Observed a panic in reconciler: runtime error: invalid memory address or nil pointer dereference	{"commit": "afe64e9", "controller": "termination", "controllerGroup": "", "controllerKind": "Node", "Node": {"name":"ip-192-168-112-11.us-east-2.compute.internal"}, "namespace": "", "name": "ip-192-168-112-11.us-east-2.compute.internal", "reconcileID": "4e585e34-4d43-412e-9f77-c5910f911e5f"}
        panic: runtime error: invalid memory address or nil pointer dereference [recovered]
        	panic: runtime error: invalid memory address or nil pointer dereference
        [signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x1f66d8e]
        
        goroutine 1021 [running]:
        [sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller](http://sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller)).Reconcile.func1()
        	[sigs.k8s.io/[email protected]/pkg/internal/controller/controller.go:118](http://sigs.k8s.io/[email protected]/pkg/internal/controller/controller.go:118) +0x1f4
        panic({0x2362b80, 0x413de40})
        	runtime/panic.go:884 +0x212
        [github.com/aws/karpenter-core/pkg/controllers/machine/terminator.(*Terminator](http://github.com/aws/karpenter-core/pkg/controllers/machine/terminator.(*Terminator)).TerminateNode(0xc000460c40, {0x2ce8a38, 0xc001d22a80}, 0xc0038b18c0)
        	[github.com/aws/[email protected]/pkg/controllers/machine/terminator/terminator.go:114](http://github.com/aws/[email protected]/pkg/controllers/machine/terminator/terminator.go:114) +0x28e
        [github.com/aws/karpenter-core/pkg/controllers/termination.(*Controller](http://github.com/aws/karpenter-core/pkg/controllers/termination.(*Controller)).Finalize(0xc000bfadb0, {0x2ce8a38, 0xc001d22a80}, 0xc0038b18c0)
        	[github.com/aws/[email protected]/pkg/controllers/termination/controller.go:78](http://github.com/aws/[email protected]/pkg/controllers/termination/controller.go:78) +0x3d1
        [github.com/aws/karpenter-core/pkg/operator/controller.(*typedDecorator[...]](http://github.com/aws/karpenter-core/pkg/operator/controller.(*typedDecorator[...])).Reconcile(0xc0004d0960, {0x2ce8a38, 0xc001d229f0}, {{{0x0, 0xc005bc0200?}, {0xc006ec93e0?, 0x7fb82d4ebaf0?}}})
        	[github.com/aws/[email protected]/pkg/operator/controller/typed.go:77](http://github.com/aws/[email protected]/pkg/operator/controller/typed.go:77) +0x669
        [sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller](http://sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller)).Reconcile(0x2ce8990?, {0x2ce8a38?, 0xc001d229f0?}, {{{0x0?, 0x2670220?}, {0xc006ec93e0?, 0x404cf4?}}})
        	[sigs.k8s.io/[email protected]/pkg/internal/controller/controller.go:121](http://sigs.k8s.io/[email protected]/pkg/internal/controller/controller.go:121) +0xc8
        [sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller](http://sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller)).reconcileHandler(0xc000f53b80, {0x2ce8990, 0xc000cb6dc0}, {0x2465aa0?, 0xc002db7a60?})
        	[sigs.k8s.io/[email protected]/pkg/internal/controller/controller.go:320](http://sigs.k8s.io/[email protected]/pkg/internal/controller/controller.go:320) +0x33c
        [sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller](http://sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller)).processNextWorkItem(0xc000f53b80, {0x2ce8990, 0xc000cb6dc0})
        	[sigs.k8s.io/[email protected]/pkg/internal/controller/controller.go:273](http://sigs.k8s.io/[email protected]/pkg/internal/controller/controller.go:273) +0x1d9
        [sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller](http://sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller)).Start.func2.2()
        	[sigs.k8s.io/[email protected]/pkg/internal/controller/controller.go:234](http://sigs.k8s.io/[email protected]/pkg/internal/controller/controller.go:234) +0x85
        created by [sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller](http://sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller)).Start.func2
        	[sigs.k8s.io/[email protected]/pkg/internal/controller/controller.go:230](http://sigs.k8s.io/[email protected]/pkg/internal/controller/controller.go:230) +0x333

How was this change tested?

make presubmit

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[coveralls]

Pull Request Test Coverage Report for Build 4108802140

• 1 of 4 (25.0%) changed or added relevant lines in 2 files are covered.
• 14 unchanged lines in 3 files lost coverage.
• Overall coverage decreased (-0.2%) to 78.312%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
pkg/controllers/termination/controller.go	0	3	0.0%

Files with Coverage Reduction	New Missed Lines	%
pkg/test/cachesyncingclient.go	2	73.91%
pkg/controllers/deprovisioning/controller.go	3	76.25%
pkg/controllers/deprovisioning/events/events.go	9	80.43%

Totals
Change from base Build 4108449011:	-0.2%
Covered Lines:	6236
Relevant Lines:	7963

---

💛 - Coveralls

[bwagner5]

LGTM