使用kubeadm搭建高可用的K8s集群

清疚 2023-09-28 05:33 4阅读 0赞

[参考地址：][Link 1]

kubeadm是官方社区推出的一个用于快速部署kubernetes集群的工具。

这个工具能通过两条指令完成一个kubernetes集群的部署：

# 创建一个 Master 节点
    $ kubeadm init
    
    # 将一个 Node 节点加入到当前集群中
    $ kubeadm join <Master节点的IP和端口 >

### 1. 安装要求 ###

在开始之前，部署Kubernetes集群机器需要满足以下几个条件：

*  一台或多台机器，操作系统 CentOS7.x-86\_x64
 *  硬件配置：2GB或更多RAM，2个CPU或更多CPU，硬盘30GB或更多
 *  可以访问外网，需要拉取镜像，如果服务器不能上网，需要提前下载镜像并导入节点
 *  禁止swap分区

### 2. 准备环境 ###

<table> 
 <thead> 
  <tr> 
   <th>角色</th> 
   <th>IP</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>k8smaster1</td> 
   <td>192.168.214.128</td> 
  </tr> 
  <tr> 
   <td>k8smaster2</td> 
   <td>192.168.214.127</td> 
  </tr> 
  <tr> 
   <td>k8snode1</td> 
   <td>192.168.214.129</td> 
  </tr> 
  <tr> 
   <td>k8snode2</td> 
   <td>192.168.214.130</td> 
  </tr> 
  <tr> 
   <td>k8s-vip（虚拟ip）</td> 
   <td>192.168.214.158</td> 
  </tr> 
 </tbody> 
</table>

# 关闭防火墙
    systemctl stop firewalld
    systemctl disable firewalld
    
    # 关闭selinux
    sed -i 's/enforcing/disabled/' /etc/selinux/config  # 永久
    setenforce 0  # 临时
    
    # 关闭swap
    swapoff -a  # 临时
    vim /etc/fstab    # 编辑这个文件， 将下面这句注释掉
    #/dev/mapper/cl-swap     swap                    swap    defaults        0 0
    # 重启生效,swap 将被永久关闭
    systemctl reboot
    
    
    # 根据规划设置主机名
    hostnamectl set-hostname <hostname>
    
    # 在master添加hosts
    cat >> /etc/hosts << EOF
    192.168.214.158    master.k8s.io   k8s-vip
    192.168.214.128    master01.k8s.io k8smaster1
    192.168.214.127    master02.k8s.io k8smaster2
    192.168.214.129    node01.k8s.io   k8snode1
    192.168.214.130    node02.k8s.io   k8snode2
    EOF
    
    # 将桥接的IPv4流量传递到iptables的链
    cat > /etc/sysctl.d/k8s.conf << EOF
    net.bridge.bridge-nf-call-ip6tables = 1
    net.bridge.bridge-nf-call-iptables = 1
    EOF
    sysctl --system  # 生效
    
    # 时间同步
    yum install ntpdate -y
    ntpdate time.windows.com

### 3. 所有master节点部署keepalived ###

#### 3.1 安装相关包和keepalived ####

yum install -y conntrack-tools libseccomp libtool-ltdl
    
    yum install -y keepalived

#### 3.2配置master节点 ####

master1节点配置

cat > /etc/keepalived/keepalived.conf <<EOF 
    ! Configuration File for keepalived
    
    global_defs {
       router_id k8s
    }
    
    vrrp_script check_haproxy {
        script "killall -0 haproxy"
        interval 3
        weight -2
        fall 10
        rise 2
    }
    
    vrrp_instance VI_1 {
        state MASTER 
        interface ens33 #此处改成你自己的网卡名称，https://www.cnblogs.com/lxmzq/articles/12627875.html 可查如何查看网卡信息
        virtual_router_id 51
        priority 250
        advert_int 1
        authentication {
            auth_type PASS
            auth_pass ceb1b3ec013d66163d6ab
        }
        virtual_ipaddress {
            192.168.214.158  # 此处需要改成你自己的虚拟IP（VIP）
        }
        track_script {
            check_haproxy
        }
    
    }
    EOF

master2节点配置

cat > /etc/keepalived/keepalived.conf <<EOF 
    ! Configuration File for keepalived
    
    global_defs {
       router_id k8s
    }
    
    vrrp_script check_haproxy {
        script "killall -0 haproxy"
        interval 3
        weight -2
        fall 10
        rise 2
    }
    
    vrrp_instance VI_1 {
        state BACKUP 
        interface ens33  # 换成你自己的网卡信息
        virtual_router_id 51
        priority 200
        advert_int 1
        authentication {
            auth_type PASS
            auth_pass ceb1b3ec013d66163d6ab
        }
        virtual_ipaddress {
            192.168.214.158  # 换成你自己的虚拟IP（VIP）
        }
        track_script {
            check_haproxy
        }
    
    }
    EOF

#### 3.3 启动和检查 ####

在两台master节点都执行

# 启动keepalived
    $ systemctl start keepalived.service
    设置开机启动
    $ systemctl enable keepalived.service
    # 查看启动状态
    $ systemctl status keepalived.service # 状态为： Active: active (running) 表未运行成功

启动后查看master1的网卡信息

ip a s ens33  # 发现网卡中多了一个虚拟IP 192.168.214.158，而Master没有，因为master1才有虚拟IP

### 4. 部署haproxy（所有master） ###

#### 4.1 安装 ####

yum install -y haproxy

#### 4.2 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

cat > /etc/haproxy/haproxy.cfg << EOF
    #---------------------------------------------------------------------
    # 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 local2
        
        chroot      /var/lib/haproxy
        pidfile     /var/run/haproxy.pid
        maxconn     4000
        user        haproxy
        group       haproxy
        daemon 
           
        # turn on stats unix socket
        stats socket /var/lib/haproxy/stats
    #---------------------------------------------------------------------
    # common defaults that all the 'listen' and 'backend' sections will
    # use if not designated in their block
    #---------------------------------------------------------------------  
    defaults
        mode                    http
        log                     global
        option                  httplog
        option                  dontlognull
        option http-server-close
        option forwardfor       except 127.0.0.0/8
        option                  redispatch
        retries                 3
        timeout http-request    10s
        timeout queue           1m
        timeout connect         10s
        timeout client          1m
        timeout server          1m
        timeout http-keep-alive 10s
        timeout check           10s
        maxconn                 3000
    #---------------------------------------------------------------------
    # kubernetes apiserver frontend which proxys to the backends
    #--------------------------------------------------------------------- 
    frontend kubernetes-apiserver
        mode                 tcp
        bind                 *:16443
        option               tcplog
        default_backend      kubernetes-apiserver    
    #---------------------------------------------------------------------
    # round robin balancing between the various backends
    #---------------------------------------------------------------------
    backend kubernetes-apiserver
        mode        tcp
        balance     roundrobin
        server      master01.k8s.io   192.168.44.155:6443 check
        server      master02.k8s.io   192.168.44.156:6443 check
    #---------------------------------------------------------------------
    # collection haproxy statistics message
    #---------------------------------------------------------------------
    listen stats
        bind                 *:1080
        stats auth           admin:awesomePassword
        stats refresh        5s
        stats realm          HAProxy\ Statistics
        stats uri            /admin?stats
    EOF

#### 4.3 启动和检查 ####

两台master都启动

# 设置开机启动
    $ systemctl enable haproxy && systemctl start haproxy
    # 查看启动状态
    $ systemctl status haproxy # 状态为： Active: active (running) 表未运行成功

检查端口

netstat -lntup|grep haproxy # yum -y install net-tools 安装netstat

### 5. 所有节点安装Docker/kubeadm/kubelet ###

Kubernetes默认CRI（容器运行时）为Docker，因此先安装Docker。

#### 5.1 安装Docker ####

# wget 安装：yum install wget -y
    $ wget https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo -O /etc/yum.repos.d/docker-ce.repo
    $ yum -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

$ cat > /etc/docker/daemon.json << EOF
    {
      "registry-mirrors": ["http://hub-mirror.c.163.com", "https://registry.docker-cn.com","https://docker.mirrors.ustc.edu.cn"]
    }
    EOF
    
    # 此时需要重启docker
    $ systemctl restart docker

#### 5.2 添加阿里云YUM软件源 ####

$ cat > /etc/yum.repos.d/kubernetes.repo << EOF
    [kubernetes]
    name=Kubernetes
    baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
    enabled=1
    gpgcheck=0
    repo_gpgcheck=0
    gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
    EOF

#### 5.3 安装kubeadm，kubelet和kubectl ####

由于版本更新频繁，这里指定版本号部署：

$ yum install -y kubelet-1.18.0 kubeadm-1.18.0 kubectl-1.18.0
    $ systemctl enable kubelet

### 6. 部署Kubernetes Master ###

#### 6.1 创建kubeadm配置文件 ####

在具有vip的master上操作，这里为master1

$ mkdir /usr/local/kubernetes/manifests -p
    
    $ cd /usr/local/kubernetes/manifests/
    
    $ vim kubeadm-config.yaml

#kubeadm-config.yaml
    apiServer:
      certSANs:
        - k8smaster1
        - k8smaster2
        - master.k8s.io
        - 192.168.214.158
        - 192.168.214.127
        - 192.168.214.128
        - 127.0.0.1
      extraArgs:
        authorization-mode: Node,RBAC
      timeoutForControlPlane: 4m0s
    apiVersion: kubeadm.k8s.io/v1beta2
    kind: ClusterConfiguration
    kubernetesVersion: stable
    controlPlaneEndpoint: "master.k8s.io:16443"
    bootstrapTokens:
    - groups:
      - system:bootstrappers:kubeadm:default-node-token
      token: abcdef.0123456789abcdef
      ttl: 24h0m0s
      usages:
      - signing
      - authentication
    kind: InitConfiguration
    localAPIEndpoint:
      # 修改为主节点 IP
      advertiseAddress: 192.168.214.128
      bindPort: 6443
    nodeRegistration:
      criSocket: /var/run/dockershim.sock
      #换成你的主节点master1的名称
      name: k8smaster1
      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
    # 国内不能访问 Google，修改为阿里云
    imageRepository: registry.aliyuncs.com/google_containers
    kind: ClusterConfiguration
    # 修改版本号
    kubernetesVersion: v1.18.0
    networking:
      dnsDomain: cluster.local
      # 配置 POD 所在网段为我们虚拟机不重叠的网段（这里用的是 Flannel 默认网段）
      podSubnet: "10.244.0.0/16"
      serviceSubnet: 10.96.0.0/12
    scheduler: {
        }

**复制到Linux上时，把注释去掉！！**

#### 6.2 在master1节点执行 ####

# 如果之前已经安装了k8s,可以进行重置操作再进行如下操作：kubeadm reset
    $ kubeadm init --config kubeadm-config.yaml #执行过程有点慢，喝杯茶，放个水

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

**按照提示保存以下内容，一会要使用：**

kubeadm join master.k8s.io:16443 --token jv5z7n.3y1zi95p952y9p65 \
        --discovery-token-ca-cert-hash sha256:403bca185c2f3a4791685013499e7ce58f9848e2213e27194b75a2e3293d8812 \
        --control-plane

查看集群状态

kubectl get cs
    
    kubectl get pods -n kube-system

### 7.安装集群网络 ###

从官方地址获取到flannel的yaml，在master1上执行

mkdir flannel
    cd flannel
    wget -c https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml

安装flannel网络

kubectl apply -f kube-flannel.yml

检查

kubectl get pods -n kube-system

### 8、master2节点加入集群 ###

#### 8.1 复制密钥及相关文件 ####

从master1复制密钥及相关文件到master2,过程中，可能需要输入登录账号与密码

$ ssh root@192.168.214.127 mkdir -p /etc/kubernetes/pki/etcd
    
    $ scp /etc/kubernetes/admin.conf root@192.168.214.127:/etc/kubernetes
       
    $ scp /etc/kubernetes/pki/{
        ca.*,sa.*,front-proxy-ca.*} root@192.168.214.127:/etc/kubernetes/pki
       
    $ scp /etc/kubernetes/pki/etcd/ca.* root@192.168.214.127:/etc/kubernetes/pki/etcd

#### 8.2 master2加入集群 ####

执行在master1上init后输出的join命令,需要带上参数`--control-plane`表示把master控制节点加入集群

$ sysctl -w net.ipv4.ip_forward=1
    #在master2上执行
    $ kubeadm join 192.168.214.128:6443 --token abcdef.0123456789abcdef \
        --discovery-token-ca-cert-hash sha256:e88668002525660857ee0d5a3aac5251f42825c1256bc96527603fff9a9fe548  --control-plane

检查状态

kubectl get node
    
    kubectl get pods --all-namespaces

### 9. 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 ckf7bs.30576l0okocepg8b     --discovery-token-ca-cert-hash sha256:19afac8b11182f61073e254fb57b9f19ab4d798b70501036fc69ebef46094aba

**集群网络重新安装，因为添加了新的node节点**

检查状态

kubectl get node
    
    kubectl get pods --all-namespaces

###  ###

### 10. 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=NodePort
    $ kubectl get pod,svc

访问地址：[http://NodeIP:Port ][http_NodeIP_Port]

[Link 1]: https://blog.csdn.net/qq_44647212/article/details/110816718
[http_NodeIP_Port]: http://NodeIP:Port