Kubeadm upgrade plan failed v1.17.11 to 1.18.20

[prabhinmp]

Hi Team,
I'm upgrading Kubernetes cluster from v1.17.11 to 1.18.20.

Environment
master - 1 node
worker- 2 nodes

Im not using external etcd . but I'm getting below error when I do kubeadm upgrade plan. command

I0825 00:49:59.791965 3510173 round_trippers.go:444] GET https://192.168.190.78:6443/api/v1/namespaces/kube-system/configmaps/kubeadm-config?timeout=10s 200 OK in 1 milliseconds I0825 00:49:59.791980 3510173 round_trippers.go:450] Response Headers: I0825 00:49:59.791985 3510173 round_trippers.go:453] Cache-Control: no-cache, private I0825 00:49:59.791991 3510173 round_trippers.go:453] Content-Type: application/json I0825 00:49:59.791998 3510173 round_trippers.go:453] Content-Length: 979 I0825 00:49:59.792011 3510173 round_trippers.go:453] Date: Wed, 25 Aug 2021 04:49:59 GMT I0825 00:49:59.792038 3510173 request.go:1068] Response Body: {"kind":"ConfigMap","apiVersion":"v1","metadata":{"name":"kubeadm-config","namespace":"kube-system","selfLink":"/api/v1/namespaces/kube-system/configmaps/kubeadm-config","uid":"de91e9af-15a6-48d6-bd75-c02df7257ed3","resourceVersion":"56870577","creationTimestamp":"2020-10-16T07:26:37Z"},"data":{"ClusterConfiguration":"apiServer:\n extraArgs:\n authorization-mode: Node,RBAC\n timeoutForControlPlane: 4m0s\napiVersion: kubeadm.k8s.io/v1beta2\ncertificatesDir: /etc/kubernetes/pki\nclusterName: kubernetes\ncontrollerManager: {}\ndns:\n type: CoreDNS\netcd:\n local:\n dataDir: /var/lib/etcd\nimageRepository: k8s.gcr.io\nkind: ClusterConfiguration\nkubernetesVersion: v1.17.17\nnetworking:\n dnsDomain: cluster.local\n podSubnet: 10.244.0.0/16\n serviceSubnet: 10.96.0.0/12\nscheduler: {}\n","ClusterStatus":"apiEndpoints:\n kubernetes-master:\n advertiseAddress: 192.168.190.78\n bindPort: 6443\napiVersion: kubeadm.k8s.io/v1beta2\nkind: ClusterStatus\n"}} I0825 00:49:59.792451 3510173 etcd.go:103] etcd endpoints read from pods: https://192.168.190.78:2379 context deadline exceeded error syncing endpoints with etc k8s.io/kubernetes/cmd/kubeadm/app/util/etcd.NewFromCluster /workspace/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/cmd/kubeadm/app/util/etcd/etcd.go:119 k8s.io/kubernetes/cmd/kubeadm/app/cmd/upgrade.runPlan /workspace/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/cmd/kubeadm/app/cmd/upgrade/plan.go:87 k8s.io/kubernetes/cmd/kubeadm/app/cmd/upgrade.NewCmdPlan.func1 /workspace/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/cmd/kubeadm/app/cmd/upgrade/plan.go:55 k8s.io/kubernetes/vendor/github.com/spf13/cobra.(*Command).execute /workspace/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/vendor/github.com/spf13/cobra/command.go:826 k8s.io/kubernetes/vendor/github.com/spf13/cobra.(*Command).ExecuteC /workspace/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/vendor/github.com/spf13/cobra/command.go:914 k8s.io/kubernetes/vendor/github.com/spf13/cobra.(*Command).Execute /workspace/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/vendor/github.com/spf13/cobra/command.go:864 k8s.io/kubernetes/cmd/kubeadm/app.Run /workspace/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/cmd/kubeadm/app/kubeadm.go:50 main.main _output/dockerized/go/src/k8s.io/kubernetes/cmd/kubeadm/kubeadm.go:25 runtime.main /usr/local/go/src/runtime/proc.go:203 runtime.goexit /usr/local/go/src/runtime/asm_amd64.s:1357

Kindly help on this.

[prabhinmp]

found below log in etcd during upgrade plan command

021-08-25 05:54:34.838997 I | embed: rejected connection from "192.168.190.78:39392" (error "remote error: tls: bad certificate", ServerName "")
2021-08-25 05:54:36.617835 I | embed: rejected connection from "192.168.190.78:39396" (error "remote error: tls: bad certificate", ServerName "")
2021-08-25 05:54:39.424431 I | embed: rejected connection from "192.168.190.78:39400" (error "remote error: tls: bad certificate", ServerName "")
2021-08-25 05:54:42.805490 I | embed: rejected connection from "192.168.190.78:39406" (error "remote error: tls: bad certificate", ServerName "")
2021-08-25 05:54:49.898988 I | embed: rejected connection from "192.168.190.78:39416" (error "remote error: tls: bad certificate", ServerName "")
2021-08-25 05:54:59.253553 I | embed: rejected connection from "192.168.190.78:39430" (error "remote error: tls: bad certificate", ServerName "")

[RA489]

/kind support

[RA489]

related to #910

[neolit123]

<1.20 is out of support. You could try refreshing the certs with 'kubeadm certs renew' before upgrade. This command is missing in older versions so download kubeadm 1.22 and use it only for that purpose. Use the 1.18 binary for the upgrade. /support

[github-actions]

Hello, @prabhinmp 🤖 👋

You seem to have troubles using Kubernetes and kubeadm.
Note that our issue trackers should not be used for providing support to users.
There are special channels for that purpose.

Please see:

• https://github.com/kubernetes/kubeadm#support