【云原生】K8S二进制搭建三：高可用配置

一、部署CoreDNS

在所有 node 节点上操作

#上传 coredns.tar 到 /opt 目录中
cd /opt
docker load -i coredns.tar

在 master01 节点上操作

#上传 coredns.yaml 文件到 /opt/k8s 目录中，部署 CoreDNS 
cd /opt/k8s
kubectl apply -f coredns.yaml

kubectl get pods -n kube-system 
NAME                          READY   STATUS    RESTARTS   AGE
coredns-5ffbfd976d-j6shb      1/1     Running   0          32s

#给kubelete绑定角色，赋予管理源权限
kubectl create clusterrolebinding cluster-system-anonymous --clusterrole=cluster-admin --user=system;anonymous



#DNS 解析测试
kubectl run -it --rm dns-test --image=busybox:1.28.4 sh
If you don't see a command prompt, try pressing enter.
/ # nslookup kubernetes
Server:    10.0.0.2
Address 1: 10.0.0.2 kube-dns.kube-system.svc.cluster.local

Name:      kubernetes
Address 1: 10.0.0.1 kubernetes.default.svc.cluster.local

二、配置高可用

初始化环境
初始化环境看这里

//从 master01 节点上拷贝证书文件、各master组件的配置文件和服务管理文件到 master02 节点
scp -r /opt/etcd/ [email protected]:/opt/
scp -r /opt/kubernetes/ [email protected]:/opt
scp /usr/lib/systemd/system/{
    
    kube-apiserver,kube-controller-manager,kube-scheduler}.service [email protected]:/usr/lib/systemd/system/
scp -r /root/.kube/  [email protected]:/root

//修改配置文件kube-apiserver中的IP
vim /opt/kubernetes/cfg/kube-apiserver
KUBE_APISERVER_OPTS="--logtostderr=true \
--v=4 \
--etcd-servers=https://192.168.80.10:2379,https://192.168.80.11:2379,https://192.168.80.12:2379 \
--bind-address=192.168.80.20 \				#修改
--secure-port=6443 \
--advertise-address=192.168.80.20 \			#修改
......

//在 master02 节点上启动各服务并设置开机自启
systemctl start kube-apiserver.service
systemctl enable kube-apiserver.service
systemctl start kube-controller-manager.service
systemctl enable kube-controller-manager.service
systemctl start kube-scheduler.service
systemctl enable kube-scheduler.service

//查看node节点状态
ln -s /opt/kubernetes/bin/* /usr/local/bin/
kubectl get nodes
kubectl get nodes -o wide			#-o=wide：输出额外信息；对于Pod，将输出Pod所在的Node名
//此时在master02节点查到的node节点状态仅是从etcd查询到的信息，而此时node节点实际上并未与master02节点建立通信连接，因此需要使用一个VIP把node节点与master节点都关联起来

三、配置负载均衡

//配置load balancer集群双机热备负载均衡（nginx实现负载均衡，keepalived实现双机热备）
##### 在lb01、lb02节点上操作 ##### 
//配置nginx的官方在线yum源，配置本地nginx的yum源
cat > /etc/yum.repos.d/nginx.repo << 'EOF'
[nginx]
name=nginx repo
baseurl=http://nginx.org/packages/centos/7/$basearch/
gpgcheck=0
EOF

yum install nginx -y

//修改nginx配置文件，配置四层反向代理负载均衡，指定k8s群集2台master的节点ip和6443端口
vim /etc/nginx/nginx.conf
events {
    
    
    worker_connections  1024;
}

#添加
stream {
    
    
    log_format  main  '$remote_addr $upstream_addr - [$time_local] $status $upstream_bytes_sent';
    
	access_log  /var/log/nginx/k8s-access.log  main;

    upstream k8s-apiserver {
    
    
        server 192.168.80.10:6443;
        server 192.168.80.20:6443;
    }
    server {
    
    
        listen 6443;
        proxy_pass k8s-apiserver;
    }
}

http {
    
    
......


//检查配置文件语法
nginx -t   

//启动nginx服务，查看已监听6443端口
systemctl start nginx
systemctl enable nginx
netstat -natp | grep nginx 


//部署keepalived服务
yum install keepalived -y

//修改keepalived配置文件
vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived

global_defs {
    
    
   # 接收邮件地址
   notification_email {
    
    
     [email protected]
     [email protected]
     [email protected]
   }
   # 邮件发送地址
   notification_email_from [email protected]
   smtp_server 127.0.0.1
   smtp_connect_timeout 30
   router_id NGINX_MASTER	#lb01节点的为 NGINX_MASTER，lb02节点的为 NGINX_BACKUP
}

#添加一个周期性执行的脚本
vrrp_script check_nginx {
    
    
    script "/etc/nginx/check_nginx.sh"	#指定检查nginx存活的脚本路径
}

vrrp_instance VI_1 {
    
    
    state MASTER			#lb01节点的为 MASTER，lb02节点的为 BACKUP
    interface ens33			#指定网卡名称 ens33
    virtual_router_id 51	#指定vrid，两个节点要一致
    priority 100			#lb01节点的为 100，lb02节点的为 90
    advert_int 1
    authentication {
    
    
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
    
    
        192.168.80.100/24	#指定 VIP
    }
    track_script {
    
    
        check_nginx			#指定vrrp_script配置的脚本
    }
}


//创建nginx状态检查脚本 
vim /etc/nginx/check_nginx.sh
#!/bin/bash
#egrep -cv "grep|$$" 用于过滤掉包含grep 或者 $$ 表示的当前Shell进程ID
count=$(ps -ef | grep nginx | egrep -cv "grep|$$")

if [ "$count" -eq 0 ];then
    systemctl stop keepalived
fi


chmod +x /etc/nginx/check_nginx.sh

//启动keepalived服务（一定要先启动了nginx服务，再启动keepalived服务）
systemctl start keepalived
systemctl enable keepalived
ip a				#查看VIP是否生成

//修改node节点上的bootstrap.kubeconfig,kubelet.kubeconfig配置文件为VIP
cd /opt/kubernetes/cfg/
vim bootstrap.kubeconfig 
server: https://192.168.80.100:6443
                      
vim kubelet.kubeconfig
server: https://192.168.80.100:6443
                        
vim kube-proxy.kubeconfig
server: https://192.168.80.100:6443

//重启kubelet和kube-proxy服务
systemctl restart kubelet.service 
systemctl restart kube-proxy.service

//在 lb01 上查看 nginx 和 node 、 master 节点的连接状态
netstat -natp | grep nginx
tcp        0      0 0.0.0.0:6443            0.0.0.0:*               LISTEN      44904/nginx: master 
tcp        0      0 0.0.0.0:80              0.0.0.0:*               LISTEN      44904/nginx: master 
tcp        0      0 192.168.80.100:6443     192.168.80.12:46954     ESTABLISHED 44905/nginx: worker 
tcp        0      0 192.168.80.14:45074     192.168.80.10:6443      ESTABLISHED 44905/nginx: worker 
tcp        0      0 192.168.80.14:53308     192.168.80.20:6443      ESTABLISHED 44905/nginx: worker 
tcp        0      0 192.168.80.14:53316     192.168.80.20:6443      ESTABLISHED 44905/nginx: worker 
tcp        0      0 192.168.80.100:6443     192.168.80.11:48784     ESTABLISHED 44905/nginx: worker 
tcp        0      0 192.168.80.14:45070     192.168.80.10:6443      ESTABLISHED 44905/nginx: worker 
tcp        0      0 192.168.80.100:6443     192.168.80.11:48794     ESTABLISHED 44905/nginx: worker 
tcp        0      0 192.168.80.100:6443     192.168.80.12:46968     ESTABLISHED 44905/nginx: worker 

在 master01 节点上测试

//测试创建pod
kubectl run nginx --image=nginx

//查看Pod的状态信息
kubectl get pods
NAME                    READY   STATUS              RESTARTS   AGE
nginx-dbddb74b8-nf9sk   0/1     ContainerCreating   0          33s   #正在创建中

kubectl get pods
NAME                    READY   STATUS    RESTARTS   AGE
nginx-dbddb74b8-nf9sk   1/1     Running   0          80s  			#创建完成，运行中

kubectl get pods -o wide
NAME                    READY   STATUS    RESTARTS   AGE   IP            NODE            NOMINATED NODE
nginx-dbddb74b8-26r9l   1/1     Running   0          10m   172.17.36.2   192.168.80.15   <none>
//READY为1/1，表示这个Pod中有1个容器

//在对应网段的node节点上操作，可以直接使用浏览器或者curl命令访问
curl 172.17.36.2

//这时在master01节点上查看nginx日志，发现没有权限查看
kubectl logs nginx-dbddb74b8-nf9sk

四、部署 Dashboard

• 仪表板是基于Web的Kubernetes用户界面。您可以使用仪表板将容器化应用程序部署到Kubernetes集群，对容器化应用程序进行故障排除，并管理集群本身及其伴随资源。您可以使用仪表板来概述群集上运行的应用程序，以及创建或修改单个Kubernetes资源（例如部署，作业，守护进程等）。例如，您可以使用部署向导扩展部署，启动滚动更新，重新启动Pod或部署新应用程序。仪表板还提供有关群集中Kubernetes资源状态以及可能发生的任何错误的信息。

在 master01 节点上操作

#上传 recommended.yaml 文件到 /opt/k8s 目录中
cd /opt/k8s
vim recommended.yaml
#默认Dashboard只能集群内部访问，修改Service为NodePort类型，暴露到外部：
kind: Service
apiVersion: v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kubernetes-dashboard
spec:
  ports:
    - port: 443
      targetPort: 8443
      nodePort: 30001     #添加
  type: NodePort          #添加
  selector:
    k8s-app: kubernetes-dashboard

kubectl apply -f recommended.yaml

#创建service account并绑定默认cluster-admin管理员集群角色
kubectl create serviceaccount dashboard-admin -n kube-system
kubectl create clusterrolebinding dashboard-admin --clusterrole=cluster-admin --serviceaccount=kube-system:dashboard-admin
kubectl describe secrets -n kube-system $(kubectl -n kube-system get secret | awk '/dashboard-admin/{print $1}')

#使用输出的token登录Dashboard
https://NodeIP:30001