使用kubeadm搭建高可用的K8s集群

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使用kubeadm搭建高可用的K8s集群

准备四个节点

在四台机器分别操作
1.设置主机名

hostnamectl set-hostname master1
hostnamectl set-hostname master2
hostnamectl set-hostname node1
hostnamectl set-hostnamek8s-vip

2.关闭防火墙

systemctl stop firewalld
systemctl disable firewalld

3.关闭selinux

sed -i 's/enforcing/disabled/' /etc/selinux/config  
setenforce 0  

4.关闭swap

swapoff -a  
sed -ri 's/.*swap.*/#&/' /etc/fstab    

5.在master添加hosts

[root@master1 ~]# cat /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
10.30.59.231 master.k8s.io       k8s-vip
10.30.59.212 master01.k8s.io     master1
10.30.59.221 master02.k8s.io     master2
10.30.59.223 node01.k8s.io       node1

6.将桥接的IPV4流量传递到iptables的链

[root@master1 ~]# cat /etc/sysctl.d/k8s.conf 
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1

生效

 [root@master1 ~]#sysctl --system 

时间同步

[root@master1 ~]#yum install ntpdate -y
[root@master1 ~]# ntpdate time.windows

master节点部署keepalived

安装相关包和keepalived

[root@master1 ~]# yum install -y conntrack-tools libseccomp libtool-ltdl
[root@master1 ~]#yum install -y keepalived

配置master1节点

[root@master1 ~]# cat /etc/keepalived/keepalived.conf 
! Configuration File for keepalived
global_defs {router_id k8s
}vrrp_script check_haproxy {script "killall -0 haproxy"interval 3weight -2fall 10rise 2
}vrrp_instance VI_1 {state MASTER interface ens192virtual_router_id 51priority 250advert_int 1authentication {auth_type PASS52auth_pass ceb1b3ec013d66163d6ab}virtual_ipaddress {10.30.59.231}track_script {check_haproxy}}

配置master2节点

[root@master2 ~]# cat /etc/keepalived/keepalived.conf 
! Configuration File for keepalivedglobal_defs {router_id k8s
}vrrp_script check_haproxy {script "killall -0 haproxy"interval 3weight -2fall 10rise 2
}vrrp_instance VI_1 {state BACKUP interface ens192virtual_router_id 51priority 200advert_int 1authentication {auth_type PASSauth_pass ceb1b3ec013d66163d6ab}virtual_ipaddress {10.30.59.231}track_script {check_haproxy}}

启动keepalived并设置为开机自启，两台master节点都需要操作

systemctl start keepalived.service
systemctl enable keepalived.service

查看启动状态

[root@master2 ~]# systemctl status keepalived.service
● keepalived.service - LVS and VRRP High Availability MonitorLoaded: loaded (/usr/lib/systemd/system/keepalived.service; enabled; vendor preset: disabled)Active: active (running) since Tue 2021-06-15 10:52:05 CST; 23h agoMain PID: 9972 (keepalived)Tasks: 3Memory: 0BCGroup: /system.slice/keepalived.service├─9972 /usr/sbin/keepalived -D├─9973 /usr/sbin/keepalived -D└─9974 /usr/sbin/keepalived -DJun 16 10:30:32 master2 Keepalived_vrrp[9974]: VRRP_Instan...
Jun 16 10:30:33 master2 Keepalived_vrrp[9974]: (VI_1): ip ...
Jun 16 10:30:33 master2 Keepalived_vrrp[9974]: bogus VRRP ...
Jun 16 10:30:33 master2 Keepalived_vrrp[9974]: VRRP_Instan...
Jun 16 10:30:34 master2 Keepalived_vrrp[9974]: (VI_1): ip ...
Jun 16 10:30:34 master2 Keepalived_vrrp[9974]: bogus VRRP ...
Jun 16 10:30:34 master2 Keepalived_vrrp[9974]: VRRP_Instan...
Jun 16 10:30:35 master2 Keepalived_vrrp[9974]: (VI_1): ip ...
Jun 16 10:30:35 master2 Keepalived_vrrp[9974]: bogus VRRP ...
Jun 16 10:30:35 master2 Keepalived_vrrp[9974]: VRRP_Instan...
Hint: Some lines were ellipsized, use -l to show in full.

查看master1的网卡信息

ip a s ens192

部署haproxy

在master节点
安装haproxy

yum install -y haproxy

配置
两台master节点的配置均相同，配置中声明了后端代理的两个master节点服务器，指定了haproxy运行的端口为16443等，因此16443端口为集群的入口

[root@master1 ~]# cat /etc/haproxy/haproxy.cfg 
#---------------------------------------------------------------------
# Global settings
#---------------------------------------------------------------------
global# to have these messages end up in /var/log/haproxy.log you will# need to:# 1) configure syslog to accept network log events.  This is done#    by adding the '-r' option to the SYSLOGD_OPTIONS in#    /etc/sysconfig/syslog# 2) configure local2 events to go to the /var/log/haproxy.log#   file. A line like the following can be added to#   /etc/sysconfig/syslog##    local2.*                       /var/log/haproxy.log#log         127.0.0.1 local2chroot      /var/lib/haproxypidfile     /var/run/haproxy.pidmaxconn     4000user        haproxygroup       haproxydaemon # turn on stats unix socketstats socket /var/lib/haproxy/stats
#---------------------------------------------------------------------
# common defaults that all the 'listen' and 'backend' sections will
# use if not designated in their block
#---------------------------------------------------------------------  
defaultsmode                    httplog                     globaloption                  httplogoption                  dontlognulloption http-server-closeoption forwardfor       except 127.0.0.0/8option                  redispatchretries                 3timeout http-request    10stimeout queue           1mtimeout connect         10stimeout client          1mtimeout server          1mtimeout http-keep-alive 10stimeout check           10smaxconn                 3000
#---------------------------------------------------------------------
# kubernetes apiserver frontend which proxys to the backends
#--------------------------------------------------------------------- 
frontend kubernetes-apiservermode                 tcpbind                 *:16443option               tcplogdefault_backend      kubernetes-apiserver    
#---------------------------------------------------------------------
# round robin balancing between the various backends
#---------------------------------------------------------------------
backend kubernetes-apiservermode        tcpbalance     roundrobinserver      master01.k8s.io   10.30.59.212:6443 checkserver      master02.k8s.io   10.30.59.221:6443 check
#---------------------------------------------------------------------
# collection haproxy statistics message
#---------------------------------------------------------------------
listen statsbind                 *:1080stats auth           admin:awesomePasswordstats refresh        5sstats realm          HAProxy\ Statisticsstats uri            /admin?stats

启动和检查
两台master都启动

设置开机启动
systemctl enable haproxy
开启haproxy
systemctl start haproxy
查看启动状态systemctl status haproxy

检查端口

[root@master1 ~]# netstat -lntup|grep haproxy
tcp        0      0 0.0.0.0:1080            0.0.0.0:*               LISTEN      11783/haproxy       
tcp        0      0 0.0.0.0:16443           0.0.0.0:*               LISTEN      11783/haproxy       
udp        0      0 0.0.0.0:59833           0.0.0.0:*                           11782/haproxy       

所有节点安装Docker/kubeadm/kubelet

安装docker

 wget .repo -O /etc/yum.repos.d/docker-ce.repoyum -y install docker-ce-18.06.1.ce-3.el7
systemctl enable docker && systemctl start docker
docker --version
Docker version 18.06.1-ce, build e68fc7a

	[root@master2 ~]#  cat  /etc/docker/daemon.json
{"registry-mirrors": [""]
}

添加阿里云YUM软件源

 [root@master2 ~]#  cat  /etc/yum.repos.d/kubernetes.repo 
[kubernetes]
name=Kubernetes
baseurl=
enabled=1
gpgcheck=0
repo_gpgcheck=0
gpgkey=.gpg .gpg

安装kubeadm，kubelet和kubectl

yum install -y kubelet-1.16.3 kubeadm-1.16.3 kubectl-1.16.3systemctl enable kubelet

部署Kubernetes Master

创建kubeadm配置文件
在master1节点

 mkdir /usr/local/kubernetes/manifests -pcd /usr/local/kubernetes/manifests/vi kubeadm-config.yaml
apiServer:certSANs:- master1- master2- master.k8s.io- 10.30.59.231- 10.30.59.212- 10.30.59.221- 127.0.0.1extraArgs:authorization-mode: Node,RBACtimeoutForControlPlane: 4m0s
apiVersion: kubeadm.k8s.io/v1beta1
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controlPlaneEndpoint: "master.k8s.io:16443"
controllerManager: {}
dns: type: CoreDNS
etcd:local:    dataDir: /var/lib/etcd
imageRepository: registry.aliyuncs/google_containers
kind: ClusterConfiguration
kubernetesVersion: v1.16.3
networking: dnsDomain: cluster.local  podSubnet: 10.244.0.0/16serviceSubnet: 10.1.0.0/16
scheduler: {}

执行

kubeadm init --config kubeadm-config.yaml

按照提示配置环境变量，使用kubectl工具：

mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
$ kubectl get nodes
$ kubectl get pods -n kube-system

保存备用
kubeadm join master.k8s.io:16443 --token u96wvh.rua3gk470xnp5562 \--discovery-token-ca-cert-hash sha256:ea8960d2a558b3d908ae34b963de087dd76a809fc3b669d343c5613820e58143 \--control-plane 	

查看集群状态

[root@master1 ~]# kubectl get cs
NAME                 AGE
controller-manager   <unknown>
scheduler            <unknown>
etcd-0               <unknown>

安装集群网络

在master1执行

mkdir flannel
cd flannel
wget -c .yml

安装flannel 网络并检查

kubectl apply -f kube-flannel.yml 
kubectl get pods -n kube-system

master2节点加入集群
复制密钥以及相关文件，从master1节点复制

# ssh root@10.30.59.221 mkdir -p /etc/kubernetes/pki/etcd# scp /etc/kubernetes/admin.conf root@10.30.59.221:/etc/kubernetes# scp /etc/kubernetes/pki/{ca.*,sa.*,front-proxy-ca.*} root@10.30.59.221:/etc/kubernetes/pki# scp /etc/kubernetes/pki/etcd/ca.* root@10.30.59.221:/etc/kubernetes/pki/etcd

master2加入集群

 kubeadm join master.k8s.io:16443 --token u96wvh.rua3gk470xnp5562 \--discovery-token-ca-cert-hash sha256:ea8960d2a558b3d908ae34b963de087dd76a809fc3b669d343c5613820e58143 \--control-plane 	  

检查状态

[root@master2 ~]# kubectl get node 
NAME      STATUS   ROLES    AGE     VERSION
master1   Ready    master   15h     v1.16.3
node1     Ready    <none>   2m57s   v1.16.3
[root@master2 ~]#kubectl get pods --all-namespaces

加入Kubernetes Node

在node1上执行

向集群添加新节点，执行在kubeadm init输出的kubeadm join命令：

kubeadm join master.k8s.io:16443 --token u96wvh.rua3gk470xnp5562 \--discovery-token-ca-cert-hash sha256:ea8960d2a558b3d908ae34b963de087dd76a809fc3b669d343c5613820e58143 \--control-plane 	  

检查状态

kubectl get node
kubectl get pods --all-namespaces

测试kubernetes集群

在Kubernetes集群中创建一个pod，验证是否正常运行：

 kubectl create deployment nginx --image=nginx
kubectl expose deployment nginx --port=80 --type=NodePortkubectl get pod,svc

访问地址：http://NodeIP:Port