使用kubeadm升级kubernetes集群

kubeadm升级k8s集群(v1.15.3 to v1.16.0版)

Kubernetes在2019年9月18日发布了年度的第三个版本1.16,本篇文章介绍使用kubeadm升级现在有的集群到v1.16.0。

Kubernetes 1.16版本的发布徽章

Kubernetes 1.16版本的发布徽章

查看k8s集群版本

查看当前的k8s版本

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[[email protected] ~]# kubectl get nodes
NAME         STATUS   ROLES    AGE   VERSION
k8s-master   Ready    master   20d   v1.15.3
k8s-node1    Ready    <none>   20d   v1.15.3
k8s-node2    Ready    <none>   20d   v1.15.3
k8s-node3    Ready    <none>   20d   v1.15.3
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[[email protected] ~]# kubeadm version
kubeadm version: &version.Info{Major:"1", Minor:"15", GitVersion:"v1.15.3", GitCommit:"2d3c76f9091b6bec110a5e63777c332469e0cba2", GitTreeState:"clean", BuildDate:"2019-08-19T11:11:18Z", GoVersion:"go1.12.9", Compiler:"gc", Platform:"linux/amd64"}
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[[email protected]master ~]# kubelet --version
Kubernetes v1.15.3


[[email protected]master ~]# systemctl status kubelet.service |grep Active
   Active: active (running) since Fri 2019-08-30 07:26:33 EDT; 3 weeks 0 days ago
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[[email protected] yum.repos.d]# kubectl version
Client Version: version.Info{Major:"1", Minor:"15", GitVersion:"v1.15.3", GitCommit:"2d3c76f9091b6bec110a5e63777c332469e0cba2", GitTreeState:"clean", BuildDate:"2019-08-19T11:13:54Z", GoVersion:"go1.12.9", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"15", GitVersion:"v1.15.3", GitCommit:"2d3c76f9091b6bec110a5e63777c332469e0cba2", GitTreeState:"clean", BuildDate:"2019-08-19T11:05:50Z", GoVersion:"go1.12.9", Compiler:"gc", Platform:"linux/amd64"}

查看版本支持

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[root@k8s-master yum.repos.d]# yum list kubelet kubeadm kubectl
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile
 * base: mirrors.aliyun.com
 * extras: mirrors.aliyun.com
 * updates: mirrors.aliyun.com
Installed Packages
kubeadm.x86_64                                                        1.15.3-0                                                        @kubernetes
kubectl.x86_64                                                        1.15.3-0                                                        @kubernetes
kubelet.x86_64                                                        1.15.3-0                                                        @kubernetes
Available Packages
kubeadm.x86_64                                                        1.16.0-0                                                        kubernetes 
kubectl.x86_64                                                        1.16.0-0                                                        kubernetes 
kubelet.x86_64                                                        1.16.0-0                                                        kubernetes

升级kubelet kubeadm kubectl版本到1.16.0(每个节点都执行)

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[[email protected] ~]# yum install -y kubelet kubeadm kubectl
# systemctl daemon-reload && systemctl restart kubelet && systemctl status kubelet


[[email protected] ~]# kubectl version
Client Version: version.Info{Major:"1", Minor:"16", GitVersion:"v1.16.0", GitCommit:"2bd9643cee5b3b3a5ecbd3af49d09018f0773c77", GitTreeState:"clean", BuildDate:"2019-09-18T14:36:53Z", GoVersion:"go1.12.9", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"15", GitVersion:"v1.15.3", GitCommit:"2d3c76f9091b6bec110a5e63777c332469e0cba2", GitTreeState:"clean", BuildDate:"2019-08-19T11:05:50Z", GoVersion:"go1.12.9", Compiler:"gc", Platform:"linux/amd64"}
[[email protected] ~]# kubelet --version
Kubernetes v1.16.0
[[email protected] ~]# kubeadm version
kubeadm version: &version.Info{Major:"1", Minor:"16", GitVersion:"v1.16.0", GitCommit:"2bd9643cee5b3b3a5ecbd3af49d09018f0773c77", GitTreeState:"clean", BuildDate:"2019-09-18T14:34:01Z", GoVersion:"go1.12.9", Compiler:"gc", Platform:"linux/amd64"}

升级k8s集群

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[[email protected] ~]# kubectl get nodes
NAME         STATUS   ROLES    AGE   VERSION
k8s-master   Ready    master   21d   v1.15.3
k8s-node1    Ready    <none>   20d   v1.15.3
k8s-node2    Ready    <none>   20d   v1.15.3
k8s-node3    Ready    <none>   20d   v1.15.3

升级集群

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[[email protected] ~]# kubeadm config print init-defaults > kubeadm1.16.yaml

[[email protected] ~]# cat kubeadm1.16.yaml 
apiVersion: kubeadm.k8s.io/v1beta2
bootstrapTokens:
- groups:
  - system:bootstrappers:kubeadm:default-node-token
  token: abcdef.0123456789abcdef
  ttl: 24h0m0s
  usages:
  - signing
  - authentication
kind: InitConfiguration
localAPIEndpoint:
  advertiseAddress: 10.122.17.200
  bindPort: 6443
nodeRegistration:
  criSocket: /var/run/dockershim.sock
  name: k8s-master
  taints:
  - effect: NoSchedule
    key: node-role.kubernetes.io/master
---
apiServer:
  timeoutForControlPlane: 4m0s
apiVersion: kubeadm.k8s.io/v1beta2
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controllerManager: {}
dns:
  type: CoreDNS
etcd:
  local:
    dataDir: /var/lib/etcd
imageRepository: registry.aliyuncs.com/google_containers
kind: ClusterConfiguration
kubernetesVersion: v1.16.0
networking:
  dnsDomain: cluster.local
  podSubnet: 192.168.0.0/16
  serviceSubnet: 10.96.0.0/12
scheduler: {}
---
apiVersion: kubeproxy.config.k8s.io/v1alpha1
kind: KubeProxyConfiguration
mode: ipvs

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[[email protected] ~]# kubeadm upgrade apply --config kubeadm1.16.yaml


.......
.......
.......
[addons] Applied essential addon: CoreDNS
[addons] Applied essential addon: kube-proxy

[upgrade/successful] SUCCESS! Your cluster was upgraded to "v1.16.0". Enjoy!

[upgrade/kubelet] Now that your control plane is upgraded, please proceed with upgrading your kubelets if you haven't already done so.

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[[email protected] ~]# kubectl version
Client Version: version.Info{Major:"1", Minor:"16", GitVersion:"v1.16.0", GitCommit:"2bd9643cee5b3b3a5ecbd3af49d09018f0773c77", GitTreeState:"clean", BuildDate:"2019-09-18T14:36:53Z", GoVersion:"go1.12.9", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"16", GitVersion:"v1.16.0", GitCommit:"2bd9643cee5b3b3a5ecbd3af49d09018f0773c77", GitTreeState:"clean", BuildDate:"2019-09-18T14:27:17Z", GoVersion:"go1.12.9", Compiler:"gc", Platform:"linux/amd64"}

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[[email protected] ~]# yum clean all
[[email protected] ~]# yum install -y kubelet kubeadm kubectl

systemctl daemon-reload && systemctl restart kubelet && systemctl status kubelet



[[email protected] ~]# kubectl version
Client Version: version.Info{Major:"1", Minor:"16", GitVersion:"v1.16.0", GitCommit:"2bd9643cee5b3b3a5ecbd3af49d09018f0773c77", GitTreeState:"clean", BuildDate:"2019-09-18T14:36:53Z", GoVersion:"go1.12.9", Compiler:"gc", Platform:"linux/amd64"}
The connection to the server localhost:8080 was refused - did you specify the right host or port?
[[email protected] ~]# kubelet --version
Kubernetes v1.16.0
[[email protected] ~]# kubeadm version
kubeadm version: &version.Info{Major:"1", Minor:"16", GitVersion:"v1.16.0", GitCommit:"2bd9643cee5b3b3a5ecbd3af49d09018f0773c77", GitTreeState:"clean", BuildDate:"2019-09-18T14:34:01Z", GoVersion:"go1.12.9", Compiler:"gc", Platform:"linux/amd64"}

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[[email protected] ~]# kubectl version
Client Version: version.Info{Major:"1", Minor:"16", GitVersion:"v1.16.0", GitCommit:"2bd9643cee5b3b3a5ecbd3af49d09018f0773c77", GitTreeState:"clean", BuildDate:"2019-09-18T14:36:53Z", GoVersion:"go1.12.9", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"16", GitVersion:"v1.16.0", GitCommit:"2bd9643cee5b3b3a5ecbd3af49d09018f0773c77", GitTreeState:"clean", BuildDate:"2019-09-18T14:27:17Z", GoVersion:"go1.12.9", Compiler:"gc", Platform:"linux/amd64"}



[[email protected] ~]# kubectl get nodes
NAME         STATUS   ROLES    AGE   VERSION
k8s-master   Ready    master   21d   v1.16.0
k8s-node1    Ready    <none>   21d   v1.16.0
k8s-node2    Ready    <none>   21d   v1.16.0
k8s-node3    Ready    <none>   21d   v1.16.0


[[email protected] ~]# kubectl get pod -A
NAMESPACE       NAME                                        READY   STATUS    RESTARTS   AGE
default         curl-6bf6db5c4f-dqw9x                       1/1     Running   2          20d
ingress-nginx   nginx-ingress-controller-6956498fcf-jkzbs   1/1     Running   1          16d
kube-system     calico-kube-controllers-65b8787765-hx9cr    1/1     Running   1          21d
kube-system     calico-node-2rlsz                           1/1     Running   1          21d
kube-system     calico-node-5vz46                           1/1     Running   1          21d
kube-system     calico-node-6szsd                           1/1     Running   1          21d
kube-system     calico-node-s5nmr                           1/1     Running   1          21d
kube-system     calicoctl                                   1/1     Running   1          20d
kube-system     coredns-58cc8c89f4-cnl45                    1/1     Running   1          26m
kube-system     coredns-58cc8c89f4-nj8hr                    1/1     Running   1          9m4s
kube-system     etcd-k8s-master                             1/1     Running   0          6m35s
kube-system     kube-apiserver-k8s-master                   1/1     Running   0          6m30s
kube-system     kube-controller-manager-k8s-master          1/1     Running   0          6m35s
kube-system     kube-proxy-52mbf                            1/1     Running   1          26m
kube-system     kube-proxy-gf75r                            1/1     Running   1          25m
kube-system     kube-proxy-hbvjf                            1/1     Running   1          26m
kube-system     kube-proxy-zppdf                            1/1     Running   1          26m
kube-system     kube-scheduler-k8s-master                   1/1     Running   0          6m31s
kube-system     kubernetes-dashboard-5dc4c54b55-c7sv2       1/1     Running   1          20d


[[email protected] ~]# kubectl get pod
NAME                    READY   STATUS    RESTARTS   AGE
curl-6bf6db5c4f-dqw9x   1/1     Running   2          20d

验证cordns

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[[email protected] ~]# kubectl get pod
NAME                    READY   STATUS    RESTARTS   AGE
curl-6bf6db5c4f-dqw9x   1/1     Running   2          20d
[[email protected] ~]# kubectl exec -it curl-6bf6db5c4f-dqw9x -- /bin/sh
/bin/sh: shopt: not found
[ [email protected]:/ ]$ nslookup kubernetes.default
Server:    10.96.0.10
Address 1: 10.96.0.10 kube-dns.kube-system.svc.cluster.local

Name:      kubernetes.default
Address 1: 10.96.0.1 kubernetes.default.svc.cluster.local
[ [email protected]:/ ]$ exit
[[email protected] ~]#

未解决的问题

kubectl get cs显示为unknown
错误提示信息示例如下:

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# kubectl get cs
NAME                 AGE
scheduler            <unknown>
controller-manager   <unknown>
etcd-0               <unknown>

这个问题似乎对集群没有太大的影响，暂未解决，后续愿意确认之后会继续更新，如果有大神知道如何解决，请指点。

参考链接

1、 https://kubernetes.io/docs/reference/setup-tools/kubeadm/kubeadm-upgrade/
2、 http://www.sohu.com/a/342118551_198222
3、 https://www.linuxidc.com/Linux/2019-09/160728.htm