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Four, kubeadm single master

2022-08-05 11:05:00 【51CTO】

1、初始化k8s软件包

       
       k8s01、k8s02、k8s03操作：
       
for i in *.gz
       
do
       
docker load -i $i
       
done
       
docker load -i k8simage-1-20-6.tar.gz
       
yum install -y kubelet-1.20.6 kubeadm-1.20.6 kubectl-1.20.6
       
systemctl enable kubelet && systemctl start kubelet
       
systemctl status kubelet
       
#上面可以看到kubelet状态不是running状态,这个是正常的,不用管,等k8s组件起来这个kubelet就正常了.
       
#注：每个软件包的作用
       
#Kubeadm: kubeadm是一个工具,用来初始化k8s集群的
       
#kubelet: 安装在集群所有节点上,用于启动Pod的
       
#kubectl: 通过kubectl可以部署和管理应用,查看各种资源,创建、删除和更新各种组件
       
Check the image version required to create a cluster
       
kubeadm config images list [--kubernetes-version <version>]
       
kubeadm config images list --kubernetes-version v1.20.6
       
[[email protected] ~]# kubeadm config images list --kubernetes-version v1.20.6
       
k8s.gcr.io/kube-apiserver:v1.20.6
       
k8s.gcr.io/kube-controller-manager:v1.20.6
       
k8s.gcr.io/kube-scheduler:v1.20.6
       
k8s.gcr.io/kube-proxy:v1.20.6
       
k8s.gcr.io/pause:3.2
       
k8s.gcr.io/etcd:3.4.13-0
       
k8s.gcr.io/coredns:1.7.0
       
Domestic pull mirror script
       
kubeadm config images pull --image-repository registry.aliyuncs.com/google_containers --kubernetes-version v1.20.6
       
Pulled is the mirror image of Ali,可以打tag成k8s.gcr.io/kube-apiserver:v1.20.6格式
      
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2、kubeadm初始化k8s集群

       
       2、kubeadm初始化k8s集群
       
kubeadm init --kubernetes-version=1.20.6  --apiserver-advertise-address=192.168.10.131  --image-repository registry.aliyuncs.com/google_containers  --pod-network-cidr=10.244.0.0/16 --ignore-preflight-errors=SystemVerification
       
#注：--image-repository registry.aliyuncs.com/google_containers：手动指定仓库地址为registry.aliyuncs.com/google_containers.kubeadm默认从k8s.grc.io拉取镜像,但是k8s.gcr.io访问不到,So you need to specify fromregistry.aliyuncs.com/google_containers仓库拉取镜像.
       
显示如下,说明安装完成：
      
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四、kubeadm单master_tomcat

       
       #配置kubectl的配置文件config,相当于对kubectl进行授权,这样kubectl命令可以使用这个证书对k8s集群进行管理
       
mkdir -p $HOME/.kube
       
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
       
sudo chown $(id -u):$(id -g) $HOME/.kube/config
       
[[email protected] ~]# kubectl get nodes
       
NAME    STATUS     ROLES                  AGE    VERSION
       
k8s01   NotReady   control-plane,master   3m8s   v1.20.6
       
#此时集群状态还是NotReady状态,因为没有安装网络插件
      
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3、扩容k8s集群-Add the first worker node

       
       在k8s01See above for the command to join a node：
       
[[email protected] ~]# kubeadm token create --print-join-command
       
kubeadm join 192.168.10.131:6443 --token m0h0jw.26okz033dler19aw     --discovery-token-ca-cert-hash sha256:5af17f226bf9c487cfb6907b8c175234f0c55ff9c00953830e9042090253a6aa
       
把k8s02加入k8s集群：
       
直接执行命令就好
      
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四、kubeadm单master_edn_02

4、扩容k8s集群-Add a second worker node

       
       在k8s01See above for the command to join a node：
       
[[email protected] ~]# kubeadm token create --print-join-command
       
kubeadm join 192.168.10.131:6443 --token hr47pk.gjozs0ecnx8vmxac     --discovery-token-ca-cert-hash sha256:5af17f226bf9c487cfb6907b8c175234f0c55ff9c00953830e9042090253a6aa
       
把k8s03加入k8s集群：
       
直接执行命令就好
      
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5、完善NODE ROLE

       
       [[email protected] ~]# kubectl get nodes
       
NAME    STATUS     ROLES                  AGE     VERSION
       
k8s01   NotReady   control-plane,master   9m54s   v1.20.6
       
k8s02   NotReady   <none>                 2m54s   v1.20.6
       
k8s03   NotReady   <none>                 62s     v1.20.6
       
#可以看到k8s02、k8s03的ROLES角色为空,<none>就表示这个节点是工作节点.
       
#可以把k8s02和k8s03的ROLES变成work,按照如下方法：
       
kubectl label node k8s02 node-role.kubernetes.io/worker=worker
       
kubectl label node k8s03 node-role.kubernetes.io/worker=worker
       
[[email protected] ~]# kubectl get nodes
       
NAME    STATUS     ROLES                  AGE     VERSION
       
k8s01   NotReady   control-plane,master   12m     v1.20.6
       
k8s02   NotReady   worker                 5m3s    v1.20.6
       
k8s03   NotReady   worker                 3m11s   v1.20.6
       
注意：The above states are allNotReady状态,Indicates that the network plug-in is not installed
      
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6、安装网络组件-Calico

       
       上传calico.yaml到k8s01上,使用yaml文件安装calico 网络插件 .
       
kubectl apply -f  calico.yaml
       
kubectl get pod -n kube-system
       
#注：在线下载配置文件地址是： https://docs.projectcalico.org/manifests/calico.yaml
       
[[email protected] ~]# kubectl get pod -n kube-system -o wide
       
NAME                                       READY   STATUS    RESTARTS   AGE     IP               NODE    NOMINATED NODE   READINESS GATES
       
calico-kube-controllers-6949477b58-qhh96   1/1     Running   0          2m52s   10.244.236.130   k8s02   <none>           <none>
       
calico-node-kfx7z                          1/1     Running   0          2m52s   192.168.10.132   k8s02   <none>           <none>
       
calico-node-khz5w                          1/1     Running   0          2m52s   192.168.10.131   k8s01   <none>           <none>
       
calico-node-z9qr9                          1/1     Running   0          2m52s   192.168.10.133   k8s03   <none>           <none>
       
coredns-7f89b7bc75-kv6kg                   1/1     Running   0          18m     10.244.235.129   k8s03   <none>           <none>
       
coredns-7f89b7bc75-m27bw                   1/1     Running   0          18m     10.244.236.129   k8s02   <none>           <none>
       
[[email protected] ~]# kubectl get nodes
       
NAME    STATUS   ROLES                  AGE   VERSION
       
k8s01   Ready    control-plane,master   20m   v1.20.6
       
k8s02   Ready    worker                 13m   v1.20.6
       
k8s03   Ready    worker                 11m   v1.20.6
      
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7、部署tomcat服务

       
       kubectl describe nodes k8s01 -n kube-system
       
Taints:             node-role.kubernetes.io/master:NoSchedule ##k8s01Stained by default
       
#把tomcat.tar.gz上传到k8s02、k8s03,手动解压
       
docker load -i tomcat.tar.gz
       
kubectl apply -f tomcat.yaml
       
[[email protected] ~]# kubectl get pods
       
NAME       READY   STATUS    RESTARTS   AGE
       
demo-pod   1/1     Running   0          8s
       
kubectl apply -f tomcat-service.yaml
       
[[email protected] ~]# kubectl get svc
       
NAME         TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)          AGE
       
kubernetes   ClusterIP   10.96.0.1      <none>        443/TCP          30m
       
tomcat       NodePort    10.107.242.7   <none>        8080:30080/TCP   5s
       
在浏览器访问ip:30080即可请求到浏览器
       
http://192.168.10.131:30080/
       
http://192.168.10.132:30080/
       
http://192.168.10.133:30080/
      
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8、测试coredns是否正常

       
       #把busybox-1-28.tar.gz上传到k8s02、k8s03,手动解压
       
docker load -i busybox-1-28.tar.gz
       
[[email protected] ~]# kubectl run busybox --image busybox:1.28 --restart=Never --rm -it busybox -- sh
       
If you don't see a command prompt, try pressing enter.
       
/ # nslookup kubernetes.default.svc.cluster.local
       
Server:    10.96.0.10
       
Address 1: 10.96.0.10 kube-dns.kube-system.svc.cluster.local
       
Name:      kubernetes.default.svc.cluster.local
       
Address 1: 10.96.0.1 kubernetes.default.svc.cluster.local
       
/ # nslookup tomcat.default.svc.cluster.local
       
Server:    10.96.0.10
       
Address 1: 10.96.0.10 kube-dns.kube-system.svc.cluster.local
       
Name:      tomcat.default.svc.cluster.local
       
Address 1: 10.107.242.7 tomcat.default.svc.cluster.local
       
/ #
       
10.96.0.10 就是我们coreDNS的clusterIP,说明coreDNS配置好了.
       
解析内部Service的名称,是通过coreDNS去解析的.
       
#注意：
       
busybox要用指定的1.28版本,不能用最新版本,最新版本,nslookup会解析不到dns和ip
      
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