kubernetes v1.14.0高可用master集群部署（使用kubeadm，离线安装）

集群方案：

• 发行版：CentOS 7
• 容器运行时
• 内核： 4.18.12-1.el7.elrepo.x86_64
• 版本：Kubernetes: 1.14.0
• 网络方案: Calico
• kube-proxy mode: IPVS
• master高可用方案：HAProxy keepalived LVS
• DNS插件: CoreDNS
• metrics插件：metrics-server
• 界面：kubernetes-dashboard

Kubernetes集群搭建

Host Name	Role	IP
master1	master1	192.168.56.103
master2	master2	192.168.56.104
master3	master3	192.168.56.105
node1	node1	192.168.56.106
node2	node2	192.168.56.107
node3	node3	192.168.56.108

1、离线安装包准备（基于能够访问外网的服务器下载相应安装包）

# 设置yum缓存路径，cachedir 缓存路径 keepcache=1保持安装包在软件安装之后不删除
cat /etc/yum.conf  
[main]
cachedir=/home/yum
keepcache=1
...

# 安装ifconfig
yum install net-tools -y

# 时间同步
yum install -y ntpdate

# 安装docker（建议19.8.06）
yum install -y yum-utils device-mapper-persistent-data lvm2
yum-config-manager \
 --add-repo \
 https://download.docker.com/linux/centos/docker-ce.repo
yum makecache fast
## 列出Docker版本
yum list docker-ce --showduplicates | sort -r
## 安装指定版本
sudo yum install docker-ce-

# 安装文件管理器，XShell可通过rz sz命令上传或者下载服务器文件
yum intall lrzsz -y

# 安装keepalived、haproxy
yum install -y socat keepalived ipvsadm haproxy

# 安装kubernetes相关组件
cat < /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=http://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=0
repo_gpgcheck=0
gpgkey=http://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg
        http://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF
yum install -y kubelet kubeadm kubectl ebtables

# 其他软件安装
yum install wget
...

2、节点系统配置

• 关闭SELinux、防火墙

  systemctl stop firewalld
  systemctl disable firewalld
  setenforce 0
  sed -i "s/SELINUX=enforcing/SELINUX=disabled/g" /etc/selinux/config
  

• 关闭系统的Swap（Kubernetes 1.8开始要求）

  swapoff -a
  yes | cp /etc/fstab /etc/fstab_bak
  cat /etc/fstab_bak |grep -v swap > /etc/fstab
  

• 配置L2网桥在转发包时会被iptables的FORWARD规则所过滤，该配置被CNI插件需要，更多信息请参考Network Plugin Requirements

  echo """
  vm.swappiness = 0
  net.bridge.bridge-nf-call-ip6tables = 1
  net.bridge.bridge-nf-call-iptables = 1
  """ > /etc/sysctl.conf
  sysctl -p
  

  centos7添加bridge-nf-call-ip6tables出现No such file or directory,简单来说就是执行一下 modprobe br_netfilter

• 同步时间

  ntpdate -u ntp.api.bz
  

• 升级内核到最新（已准备内核离线安装包，可选）

  centos7 升级内核

  参考文章

  grub2-set-default 0 && grub2-mkconfig -o /etc/grub2.cfg
  grubby --default-kernel
  grubby --args="user_namespace.enable=1" --update-kernel="$(grubby --default-kernel)"
  

• 重启系统，确认内核版本后，开启IPVS（如果未升级内核，去掉ip_vs_fo）

  uname -a
  cat > /etc/sysconfig/modules/ipvs.modules < /dev/null 2>&1
      if [ $? -eq 0 ]; then
          /sbin/modprobe \${kernel_module}
      fi
  done
  EOF
  chmod 755 /etc/sysconfig/modules/ipvs.modules && bash /etc/sysconfig/modules/ipvs.modules && lsmod | grep ip_vs
  

  执行sysctl -p报错可执行modprobe br_netfilter，请参考centos7添加bridge-nf-call-ip6tables出现No such file or directory
  

• 所有机器需要设定/etc/sysctl.d/k8s.conf的系统参数

  # https://github.com/moby/moby/issues/31208 
  # ipvsadm -l --timout
  # 修复ipvs模式下长连接timeout问题 小于900即可
  cat < /etc/sysctl.d/k8s.conf
  net.ipv4.tcp_keepalive_time = 600
  net.ipv4.tcp_keepalive_intvl = 30
  net.ipv4.tcp_keepalive_probes = 10
  net.ipv6.conf.all.disable_ipv6 = 1
  net.ipv6.conf.default.disable_ipv6 = 1
  net.ipv6.conf.lo.disable_ipv6 = 1
  net.ipv4.neigh.default.gc_stale_time = 120
  net.ipv4.conf.all.rp_filter = 0
  net.ipv4.conf.default.rp_filter = 0
  net.ipv4.conf.default.arp_announce = 2
  net.ipv4.conf.lo.arp_announce = 2
  net.ipv4.conf.all.arp_announce = 2
  net.ipv4.ip_forward = 1
  net.ipv4.tcp_max_tw_buckets = 5000
  net.ipv4.tcp_syncookies = 1
  net.ipv4.tcp_max_syn_backlog = 1024
  net.ipv4.tcp_synack_retries = 2
  net.bridge.bridge-nf-call-ip6tables = 1
  net.bridge.bridge-nf-call-iptables = 1
  net.netfilter.nf_conntrack_max = 2310720
  fs.inotify.max_user_watches=89100
  fs.may_detach_mounts = 1
  fs.file-max = 52706963
  fs.nr_open = 52706963
  net.bridge.bridge-nf-call-arptables = 1
  vm.swappiness = 0
  vm.overcommit_memory=1
  vm.panic_on_oom=0
  EOF
  sysctl --system
  

• 设置开机启动

  # 启动docker
  sed -i "13i ExecStartPost=/usr/sbin/iptables -P FORWARD ACCEPT" /usr/lib/systemd/system/docker.service
  systemctl daemon-reload
  systemctl enable docker
  systemctl start docker
  # 设置kubelet开机启动
  systemctl enable kubelet
  
  systemctl enable keepalived
  systemctl enable haproxy
  

• 设置免密登录

  # 1、三次回车后，密钥生成完成
  ssh-keygen
  # 2、拷贝密钥到其他节点
  ssh-copy-id -i ~/.ssh/id_rsa.pub  用户名字@192.168.x.xxx
  

**、 Kubernetes要求集群中所有机器具有不同的Mac地址、产品uuid、Hostname。

3、keepalived+haproxy配置

cd ~/
# 创建集群信息文件
echo """
CP0_IP=192.168.56.103
CP1_IP=192.168.56.104
CP2_IP=192.168.56.105
VIP=192.168.56.102
NET_IF=eth0
CIDR=10.244.0.0/16
""" > ./cluster-info
bash -c "$(curl -fsSL https://raw.githubusercontent.com/hnbcao/kubeadm-ha-master/v1.14.0/keepalived-haproxy.sh)"

4、部署HA Master

HA Master的部署过程已经自动化，请在master-1上执行如下命令，并注意修改IP;

脚本主要执行三步：

1)、重置kubelet设置

kubeadm reset -f
rm -rf /etc/kubernetes/pki/

2)、编写节点配置文件并初始化master1的kubelet

echo """
apiVersion: kubeadm.k8s.io/v1beta1
kind: ClusterConfiguration
kubernetesVersion: v1.13.0
controlPlaneEndpoint: "${VIP}:8443"
maxPods: 100
networkPlugin: cni
imageRepository: registry.aliyuncs.com/google_containers
apiServer:
  certSANs:
  - ${CP0_IP}
  - ${CP1_IP}
  - ${CP2_IP}
  - ${VIP}
networking:
  # This CIDR is a Calico default. Substitute or remove for your CNI provider.
  podSubnet: ${CIDR}
---
apiVersion: kubeproxy.config.k8s.io/v1alpha1
kind: KubeProxyConfiguration
mode: ipvs
""" > /etc/kubernetes/kubeadm-config.yaml
kubeadm init --config /etc/kubernetes/kubeadm-config.yaml
mkdir -p $HOME/.kube
cp -f /etc/kubernetes/admin.conf ${HOME}/.kube/config

• 关于默认网关问题，如果有多张网卡，需要先将默认网关切换到集群使用的那张网卡上，否则可能会出现etcd无法连接等问题。（应用我用的虚拟机，有一张网卡无法做到各个节点胡同；route查看当前网关信息，route del default删除默认网关，route add default enth0设置默认网关enth0为网卡名）

3)、拷贝相关证书到master2、master3

for index in 1 2; do
  ip=${IPS[${index}]}
  ssh $ip "mkdir -p /etc/kubernetes/pki/etcd; mkdir -p ~/.kube/"
  scp /etc/kubernetes/pki/ca.crt $ip:/etc/kubernetes/pki/ca.crt
  scp /etc/kubernetes/pki/ca.key $ip:/etc/kubernetes/pki/ca.key
  scp /etc/kubernetes/pki/sa.key $ip:/etc/kubernetes/pki/sa.key
  scp /etc/kubernetes/pki/sa.pub $ip:/etc/kubernetes/pki/sa.pub
  scp /etc/kubernetes/pki/front-proxy-ca.crt $ip:/etc/kubernetes/pki/front-proxy-ca.crt
  scp /etc/kubernetes/pki/front-proxy-ca.key $ip:/etc/kubernetes/pki/front-proxy-ca.key
  scp /etc/kubernetes/pki/etcd/ca.crt $ip:/etc/kubernetes/pki/etcd/ca.crt
  scp /etc/kubernetes/pki/etcd/ca.key $ip:/etc/kubernetes/pki/etcd/ca.key
  scp /etc/kubernetes/admin.conf $ip:/etc/kubernetes/admin.conf
  scp /etc/kubernetes/admin.conf $ip:~/.kube/config

  ssh ${ip} "${JOIN_CMD} --experimental-control-plane"
done

4)、master2、master3加入节点

JOIN_CMD=`kubeadm token create --print-join-command`
ssh ${ip} "${JOIN_CMD} --experimental-control-plane"

完整脚本：

# 部署HA master
 
bash -c "$(curl -fsSL https://raw.githubusercontent.com/hnbcao/kubeadm-ha-master/v1.14.0/kube-ha.sh)"

5、加入节点

• 各个节点需要配置keepalived 和 haproxy

  #/etc/haproxy/haproxy.cfg
  global
      log         127.0.0.1 local2
      chroot      /var/lib/haproxy
      pidfile     /var/run/haproxy.pid
      maxconn     4000
      user        haproxy
      group       haproxy
      daemon
      stats socket /var/lib/haproxy/stats
  
  defaults
      mode                    tcp
      log                     global
      option                  tcplog
      option                  dontlognull
      option                  redispatch
      retries                 3
      timeout queue           1m
      timeout connect         10s
      timeout client          1m
      timeout server          1m
      timeout check           10s
      maxconn                 3000
  
  listen stats
      mode   http
      bind :10086
      stats   enable
      stats   uri     /admin?stats
      stats   auth    admin:admin
      stats   admin   if TRUE
      
  frontend  k8s_https *:8443
      mode      tcp
      maxconn      2000
      default_backend     https_sri
      
  backend https_sri
      balance      roundrobin
      server master1-api ${MASTER1_IP}:6443  check inter 10000 fall 2 rise 2 weight 1
      server master2-api ${MASTER2_IP}:6443  check inter 10000 fall 2 rise 2 weight 1
      server master3-api ${MASTER3_IP}:6443  check inter 10000 fall 2 rise 2 weight 1
  

  #/etc/keepalived/keepalived.conf 
  global_defs {
     router_id LVS_DEVEL
  }
  
  vrrp_script check_haproxy {
      script /etc/keepalived/check_haproxy.sh
      interval 3
  }
  
  vrrp_instance VI_1 {
      state MASTER
      interface eth0
      virtual_router_id 80
      priority 100
      advert_int 1
      authentication {
          auth_type PASS
          auth_pass just0kk
      }
      virtual_ipaddress {
          ${VIP}/24
      }
      track_script {   
          check_haproxy
      }
  }
  
  }
  

注意两个配置中的{MASTER2 _ IP}, {VIP}需要替换为自己集群相应的IP地址

• 重启keepalived和haproxy

  systemctl stop keepalived
  systemctl enable keepalived
  systemctl start keepalived
  systemctl stop haproxy
  systemctl enable haproxy
  systemctl start haproxy
  

• 节点加入命令获取

  #master节点执行该命令，再在节点执行获取到的命令
  kubeadm token create --print-join-command
  

6、结束安装

当前集群安装完毕，还需要安装cni插件，推荐使用calico，性能优于其他。