segfault validating cluster update after changing cluster name

[erickt]

I just tried to rename a cluster with kops with commit ea31478 and I got a segfault or nil pointer dereference. I did kops edit cluster and then changed the the metadata from:

...
metadata:
  name: <SOME_DOMAIN>
...

To:

...
metadata:
  name: cluster.<SOME_DOMAIN>
...

Kops produced this backtrace:

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x2c0 pc=0x1e97532]

goroutine 1 [running]:
k8s.io/kops/pkg/apis/kops/validation.ValidateClusterUpdate(0xc420246700, 0xc4201c4c20, 0x0, 0x0, 0x0, 0x0)
	/Users/erickt/gopath/src/k8s.io/kops/pkg/apis/kops/validation/cluster.go:39 +0x262
k8s.io/kops/pkg/client/simple/vfsclientset.(*ClusterVFS).Update(0xc4207bdcc0, 0xc420246700, 0xc4201c4c20, 0xc4207bdb80, 0xc420d5f1b8, 0xc420d5f1b8)
	/Users/erickt/gopath/src/k8s.io/kops/pkg/client/simple/vfsclientset/cluster.go:125 +0xd6
k8s.io/kops/pkg/client/simple/vfsclientset.(*VFSClientset).UpdateCluster(0xc4207f7650, 0xc420246700, 0xc4201c4c20, 0x0, 0x0, 0x0)
	/Users/erickt/gopath/src/k8s.io/kops/pkg/client/simple/vfsclientset/clientset.go:44 +0x4d
main.RunEditCluster(0xc420822460, 0xc420058fc0, 0xc4207f74a0, 0x0, 0x1, 0x5aeb180, 0xc42000e018, 0x5cb0060, 0x1, 0xc42000e528)
	/Users/erickt/gopath/src/k8s.io/kops/cmd/kops/edit_cluster.go:247 +0x1221
main.NewCmdEditCluster.func1(0xc420058fc0, 0xc4207f74a0, 0x0, 0x1)
	/Users/erickt/gopath/src/k8s.io/kops/cmd/kops/edit_cluster.go:70 +0x71
k8s.io/kops/vendor/github.com/spf13/cobra.(*Command).execute(0xc420058fc0, 0xc4207f7490, 0x1, 0x1, 0xc420058fc0, 0xc4207f7490)
	/Users/erickt/gopath/src/k8s.io/kops/vendor/github.com/spf13/cobra/command.go:603 +0x234
k8s.io/kops/vendor/github.com/spf13/cobra.(*Command).ExecuteC(0x5c7b8e0, 0x385bc00, 0x0, 0x0)
	/Users/erickt/gopath/src/k8s.io/kops/vendor/github.com/spf13/cobra/command.go:689 +0x2fe
k8s.io/kops/vendor/github.com/spf13/cobra.(*Command).Execute(0x5c7b8e0, 0x5cb0060, 0x0)
	/Users/erickt/gopath/src/k8s.io/kops/vendor/github.com/spf13/cobra/command.go:648 +0x2b
main.Execute()
	/Users/erickt/gopath/src/k8s.io/kops/cmd/kops/root.go:98 +0x91
main.main()
	/Users/erickt/gopath/src/k8s.io/kops/cmd/kops/main.go:25 +0x20

[chrislovecnm]

@erickt we need to improve validation, but you should not be able to change that field ;)

[chrislovecnm]

Somehow the old cluster is coming back as nil, probably because he name has changed :) We need to fix the nil, and fix the validation.

[justinsb]

We're no longer going to segfault as of #3935. We do need validation that changing the name is not permitted.

[fejta-bot]

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[fejta-bot]

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Mark the issue as fresh with /remove-lifecycle rotten.
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If this issue is safe to close now please do so with /close.

Send feedback to sig-testing, kubernetes/test-infra and/or fejta.
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[mikesplain]

/close