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：

  1. # 创建一个 Master 节点
  2. $ kubeadm init
  4. # 将一个 Node 节点加入到当前集群中
  5. $ 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

角色 IP
master1 192.168.44.155
master2 192.168.44.156
node1 192.168.44.157
VIP（虚拟ip） 192.168.44.158 
  1. # 关闭防火墙
  2. systemctl stop firewalld
  3. systemctl disable firewalld
  5. # 关闭selinux
  6. sed -i 's/enforcing/disabled/' /etc/selinux/config  # 永久
  7. setenforce 0  # 临时
  9. # 关闭swap
  10. swapoff -a  # 临时
  11. sed -ri 's/.*swap.*/#&/' /etc/fstab    # 永久
  13. # 根据规划设置主机名
  14. hostnamectl set-hostname <hostname>
  16. # 在master添加hosts
  17. cat >> /etc/hosts << EOF
  18. 192.168.44.158    master.k8s.io   k8s-vip
  19. 192.168.44.155    master01.k8s.io master1
  20. 192.168.44.156    master02.k8s.io master2
  21. 192.168.44.157    node01.k8s.io   node1
  22. EOF
  24. # 将桥接的IPv4流量传递到iptables的链
  25. cat > /etc/sysctl.d/k8s.conf << EOF
  26. net.bridge.bridge-nf-call-ip6tables = 1
  27. net.bridge.bridge-nf-call-iptables = 1
  28. EOF
  29. sysctl --system  # 生效
  31. # 时间同步
  32. yum install ntpdate -y
  33. ntpdate time.windows.com

3. 所有master节点部署keepalived

3.1 安装相关包和keepalived

  1. yum install -y conntrack-tools libseccomp libtool-ltdl
  3. yum install -y keepalived

3.2配置master节点

master1节点配置

  1. cat > /etc/keepalived/keepalived.conf <<EOF 
  2. ! Configuration File for keepalived
  4. global_defs {
  5.    router_id k8s
  6. }
  8. vrrp_script check_haproxy {
  9.     script "killall -0 haproxy"
  10.     interval 3
  11.     weight -2
  12.     fall 10
  13.     rise 2
  14. }
  16. vrrp_instance VI_1 {
  17.     state MASTER 
  18.     interface ens33 
  19.     virtual_router_id 51
  20.     priority 250
  21.     advert_int 1
  22.     authentication {
  23.         auth_type PASS
  24.         auth_pass ceb1b3ec013d66163d6ab
  25.     }
  26.     virtual_ipaddress {
  27.         192.168.44.158
  28.     }
  29.     track_script {
  30.         check_haproxy
  31.     }
  33. }
  34. EOF

master2节点配置

  1. cat > /etc/keepalived/keepalived.conf <<EOF 
  2. ! Configuration File for keepalived
  4. global_defs {
  5.    router_id k8s
  6. }
  8. vrrp_script check_haproxy {
  9.     script "killall -0 haproxy"
  10.     interval 3
  11.     weight -2
  12.     fall 10
  13.     rise 2
  14. }
  16. vrrp_instance VI_1 {
  17.     state BACKUP 
  18.     interface ens33 
  19.     virtual_router_id 51
  20.     priority 200
  21.     advert_int 1
  22.     authentication {
  23.         auth_type PASS
  24.         auth_pass ceb1b3ec013d66163d6ab
  25.     }
  26.     virtual_ipaddress {
  27.         192.168.44.158
  28.     }
  29.     track_script {
  30.         check_haproxy
  31.     }
  33. }
  34. EOF

3.3 启动和检查

在两台master节点都执行

  1. # 启动keepalived
  2. $ systemctl start keepalived.service
  3. 设置开机启动
  4. $ systemctl enable keepalived.service
  5. # 查看启动状态
  6. $ systemctl status keepalived.service

启动后查看master1的网卡信息

  1. ip a s ens33

4. 部署haproxy

4.1 安装

  1. 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

  1. cat > /etc/haproxy/haproxy.cfg << EOF
  2. #---------------------------------------------------------------------
  3. # Global settings
  4. #---------------------------------------------------------------------
  5. global
  6.     # to have these messages end up in /var/log/haproxy.log you will
  7.     # need to:
  8.     # 1) configure syslog to accept network log events.  This is done
  9.     #    by adding the '-r' option to the SYSLOGD_OPTIONS in
  10.     #    /etc/sysconfig/syslog
  11.     # 2) configure local2 events to go to the /var/log/haproxy.log
  12.     #   file. A line like the following can be added to
  13.     #   /etc/sysconfig/syslog
  14.     #
  15.     #    local2.*                       /var/log/haproxy.log
  16.     #
  17.     log         127.0.0.1 local2
  19.     chroot      /var/lib/haproxy
  20.     pidfile     /var/run/haproxy.pid
  21.     maxconn     4000
  22.     user        haproxy
  23.     group       haproxy
  24.     daemon 
  26.     # turn on stats unix socket
  27.     stats socket /var/lib/haproxy/stats
  28. #---------------------------------------------------------------------
  29. # common defaults that all the 'listen' and 'backend' sections will
  30. # use if not designated in their block
  31. #---------------------------------------------------------------------  
  32. defaults
  33.     mode                    http
  34.     log                     global
  35.     option                  httplog
  36.     option                  dontlognull
  37.     option http-server-close
  38.     option forwardfor       except 127.0.0.0/8
  39.     option                  redispatch
  40.     retries                 3
  41.     timeout http-request    10s
  42.     timeout queue           1m
  43.     timeout connect         10s
  44.     timeout client          1m
  45.     timeout server          1m
  46.     timeout http-keep-alive 10s
  47.     timeout check           10s
  48.     maxconn                 3000
  49. #---------------------------------------------------------------------
  50. # kubernetes apiserver frontend which proxys to the backends
  51. #--------------------------------------------------------------------- 
  52. frontend kubernetes-apiserver
  53.     mode                 tcp
  54.     bind                 *:16443
  55.     option               tcplog
  56.     default_backend      kubernetes-apiserver    
  57. #---------------------------------------------------------------------
  58. # round robin balancing between the various backends
  59. #---------------------------------------------------------------------
  60. backend kubernetes-apiserver
  61.     mode        tcp
  62.     balance     roundrobin
  63.     server      master01.k8s.io   192.168.44.155:6443 check
  64.     server      master02.k8s.io   192.168.44.156:6443 check
  65. #---------------------------------------------------------------------
  66. # collection haproxy statistics message
  67. #---------------------------------------------------------------------
  68. listen stats
  69.     bind                 *:1080
  70.     stats auth           admin:awesomePassword
  71.     stats refresh        5s
  72.     stats realm          HAProxy\ Statistics
  73.     stats uri            /admin?stats
  74. EOF

4.3 启动和检查

两台master都启动

  1. # 设置开机启动
  2. $ systemctl enable haproxy
  3. # 开启haproxy
  4. $ systemctl start haproxy
  5. # 查看启动状态
  6. $ systemctl status haproxy

检查端口

  1. netstat -lntup|grep haproxy

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

  1. $ wget https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo -O /etc/yum.repos.d/docker-ce.repo
  2. $ yum -y install docker-ce-18.06.1.ce-3.el7
  3. $ systemctl enable docker && systemctl start docker
  4. $ docker --version
  5. Docker version 18.06.1-ce, build e68fc7a
  1. $ cat > /etc/docker/daemon.json << EOF
  2. {
  3.   "registry-mirrors": ["https://b9pmyelo.mirror.aliyuncs.com"]
  4. }
  5. EOF

5.2 添加阿里云YUM软件源

  1. $ cat > /etc/yum.repos.d/kubernetes.repo << EOF
  2. [kubernetes]
  3. name=Kubernetes
  4. baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
  5. enabled=1
  6. gpgcheck=0
  7. repo_gpgcheck=0
  8. gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
  9. 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：

  1. $ yum install -y kubelet-1.16.3 kubeadm-1.16.3 kubectl-1.16.3
  2. $ 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

  1. $ mkdir /usr/local/kubernetes/manifests -p
  3. $ cd /usr/local/kubernetes/manifests/
  5. $ vi kubeadm-config.yaml
  7. apiServer:
  8.   certSANs:
  9.     - master1
  10.     - master2
  11.     - master.k8s.io
  12.     - 192.168.242.100
  13.     - 192.168.242.105
  14.     - 192.168.242.151
  15.     - 127.0.0.1
  16.   extraArgs:
  17.     authorization-mode: Node,RBAC
  18.   timeoutForControlPlane: 4m0s
  19. apiVersion: kubeadm.k8s.io/v1beta1
  20. certificatesDir: /etc/kubernetes/pki
  21. clusterName: kubernetes
  22. controlPlaneEndpoint: "master.k8s.io:16443"
  23. controllerManager: {}
  24. dns: 
  25.   type: CoreDNS
  26. etcd:
  27.   local:    
  28.     dataDir: /var/lib/etcd
  29. imageRepository: registry.aliyuncs.com/google_containers
  30. kind: ClusterConfiguration
  31. kubernetesVersion: v1.16.3
  32. networking: 
  33.   dnsDomain: cluster.local  
  34.   podSubnet: 10.244.0.0/16
  35.   serviceSubnet: 10.1.0.0/16
  36. scheduler: {}

6.2 在master1节点执行

  1. $ kubeadm init --config kubeadm-config.yaml

按照提示配置环境变量，使用kubectl工具：

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

按照提示保存以下内容，一会要使用：

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

查看集群状态

  1. kubectl get cs
  3. 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

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

安装flannel网络

  1. kubectl apply -f kube-flannel.yml

检查

  1. 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

从具有vip的master1复制密钥及相关文件到master2

  1. # ssh root@192.168.44.156 mkdir -p /etc/kubernetes/pki/etcd
  3. # scp /etc/kubernetes/admin.conf root@192.168.44.156:/etc/kubernetes
  5. # scp /etc/kubernetes/pki/{ca.*,sa.*,front-proxy-ca.*} root@192.168.44.156:/etc/kubernetes/pki
  7. # scp /etc/kubernetes/pki/etcd/ca.* root@192.168.44.156:/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

  1. kubeadm join master.k8s.io:16443 --token ckf7bs.30576l0okocepg8b     --discovery-token-ca-cert-hash sha256:19afac8b11182f61073e254fb57b9f19ab4d798b70501036fc69ebef46094aba --control-plane

检查状态

  1. kubectl get node
  3. kubectl get pods --all-namespaces

5. 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：

  1. 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

  1. kubectl get node
  3. kubectl get pods --all-namespaces

7. 测试kubernetes集群

在Kubernetes集群中创建一个pod，验证是否正常运行：

  1. $ kubectl create deployment nginx --image=nginx
  2. $ kubectl expose deployment nginx --port=80 --type=NodePort
  3. $ kubectl get pod,svc

访问地址：http://NodeIP:Port