升级coredns

一、查看当前coredns版本

[root@k8s-master01 ~]# kubectl get pod -n kube-system coredns-6ccb5d565f-8fjrk -oyaml | grep image
    image: coredns/coredns:1.8.0
    imagePullPolicy: IfNotPresent
    image: coredns/coredns:1.8.0

二、升级

2.1、coredns介绍

# coredns官网：https://github.com/coredns/coredns
# 老版本用：kube-dns
# 新版的都用：coredns3


# 部署文档：https://github.com/coredns/deployment/tree/master/kubernetes

2.2、备份原来的cm、deploy、clusterrole、clusterrolebinding

[root@k8s-master01 ~]# kubectl get cm -n kube-system coredns -oyaml > coredns-config.yaml
[root@k8s-master01 ~]# kubectl get deploy -n kube-system coredns -oyaml > coredns-controllers.yaml
[root@k8s-master01 ~]# kubectl get clusterrole system:coredns -oyaml > coredns-clusterrole.yaml
[root@k8s-master01 ~]# kubectl get clusterrolebinding  system:coredns -oyaml > coredns-clusterrolebinding.yaml

2.3、升级

# 1、下载文件
[root@k8s-master01 ~]# git clone https://github.com/coredns/deployment.git

# 2、升级
[root@k8s-master01 ~]# cd deployment/kubernetes/
[root@k8s-master01 kubernetes]# ./deploy.sh -s | kubectl apply -f -