環境准備：
master：192.168.1.118 系統：CentOS 7.3
node1：192.168.1.155 系統：CentOS 7.3
node2：192.168.1.156 系統：CentOS 7.3
（1）借助於NTP服務設定各節點時間精確同步；若節點可直接訪問互聯網，直接啟動chronyd系統服務，並設定隨系統引導而啟動
（2）通過DNS完成各節點的主機名稱解析，測試環境主機數量較少時也可以使用hosts文件進行；
（3）關閉各節點的iptables或firewalld服務，確保它們被禁止隨系統引導過程啟動；
（4）各節點禁用SELinux
（5）各節點禁用所有Swap設備；
（6）若要使用ipvs模型的proxy，各節點還需要載入ipvs相關的各模塊；
[Master + Node基礎配置]
#解析主機名
192.168.1.118 master
192.168.1.155 node1
192.168.1.156 node2
#部署集群時，kubeadm默認會預先檢查當前主機是否禁用了Swap設備，並在未禁用時強制終止部署過程；因此，在主機內存資源充裕的條件下，需要禁用所有Swap設備，否則，就需要在后文kubeadm init及kubeadm join命令執行時額外使用相關的選項忽略檢查錯誤。
關閉Swap設備，首先關閉當前已啟用的所有Swap設備：
~]#swapoff -a
而后編輯/etc/fstab配置文件，注釋用於掛載Swap設備的所有行
#下載阿里雲docker-ce源
~]# cd /etc/yum.repos.d/
wget https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
#安裝docker和kubernetes服務
~]# yum install docker-ce -y
#若要通過默認的k8s.gcr.io鏡像殘酷獲取Kubernetes系統組件的相關鏡像，需要配置docker Unit File (/usr/lib/systemd/system/docker.service文件)中的Environment變量，為其定義合用的HTTPS_PROXY
~]# vim /usr/lib/systemd/system/docker.service
.......
[Service]
Type=notify
# the default is not to use systemd for cgroups because the delegate issues still
# exists and systemd currently does not support the cgroup feature set required
# for containers run by docker
Environment="HTTPS_PROXY=http://www.ik8s.io:10070"
Environment="NO_PROXY=127.0.0.0/8,192.168.1.0/24" #本地IP訪問無需代理
ExecStart=/usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock
ExerStartPost=/usr/bin/iptables -P FORWARD ACCEPT #docker自1.13版本起會自動設置iptables的FORWARD默認策略為DROP，這可能會影響Kubernetes集群依賴的報文轉發功能，因此需要在docker服務啟動后，重新將FORWARD鏈的默認策略設備為ACCEPT，在“ExecStart=/usr/bin/dockerd”添加這一段
ExecReload=/bin/kill -s HUP $MAINPID
TimeoutSec=0
RestartSec=2
Restart=always
.......
~]# systemctl daemon-reload #重載配置文件
~]# systemctl start docker #啟動docker
#跟橋接設置的兩個參數必須為1
~]# sysctl -a | grep bridge
~]# vim /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
~]# sysctl -p /etc/sysctl.d/k8s.conf #讓系統重讀一下配置
#創建kubernetes阿里雲源
~]# cd /etc/yum.repos.d/
yum.repos.d]# vim kubernetes.repo
[kubernetes]
name=Kubernetes Repository
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/
gpgcheck=1
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg
~]# yum install kubelet kubectl kubeadm -y
~]# systemctl enable docker kubelet #將docker和kubelet設置開機自啟動
#開始下載kubernetes組件的鏡像文件，如果沒法直接連接到k8s官網則從國內下載鏡像文件然后打標簽即可
~]# rpm -qa|grep kubeadm #下載鏡像前要先確認系統中kubeadm的版本，版本要匹配否則會報錯
kubeadm-1.13.4-0.x86_64
~]# kubeadm config images pull
[config/images] Pulled k8s.gcr.io/kube-apiserver:v1.13.4
[config/images] Pulled k8s.gcr.io/kube-controller-manager:v1.13.4
[config/images] Pulled k8s.gcr.io/kube-scheduler:v1.13.4
[config/images] Pulled k8s.gcr.io/kube-proxy:v1.13.4
[config/images] Pulled k8s.gcr.io/pause:3.1
[config/images] Pulled k8s.gcr.io/etcd:3.2.24
[config/images] Pulled k8s.gcr.io/coredns:1.2.6
#確認鏡像文件是否下載完成
[Master 配置]
#若未禁用Swap設備，則需要編輯kubelet的配置文件/etc/sysconfig/kubelet，設置忽略Swap啟用的狀態錯誤，內容如下：
~]# vim /etc/sysconfig/kubelet
KUBELET_EXTRA_ARGS="--fail-swap-on=false"
#初始化kubernetes，10.244.0.0/16是flannel默認的網段所以我們這里不做更改，
~]# kubeadm init --kubernetes-version="v1.13.4" --pod-network-cidr="10.244.0.0/16" --ignore-preflight-errors=Swap
.......
Your Kubernetes master has initialized successfully!
To start using your cluster, you need to run the following as a regular user:
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
You should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
https://kubernetes.io/docs/concepts/cluster-administration/addons/
You can now join any number of machines by running the following on each node
as root:
kubeadm join 192.168.1.118:6443 --token gx1knl.wts9qo4ebghwk242 --discovery-token-ca-cert-hash sha256:bd7bb24b445dc95f0571c501bdc4e82aa23fdc8a7194a571790923b7d4b10468 #這段要記錄起來，用來給node加入到集群中用
#確認6443端口是否已經啟用了
#要開始使用集群，需要以常規用戶身份運行以下命令（為了方便這里就用root用戶執行了）
~]# mkdir -p $HOME/.kube
~]# cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
#開始安裝網絡插件flannel，Kubernetes版本大於1.7+的可以直接執行下面這條命令下載
~]# kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
clusterrole.rbac.authorization.k8s.io/flannel created
clusterrolebinding.rbac.authorization.k8s.io/flannel created
serviceaccount/flannel created configmap/kube-flannel-cfg created
daemonset.extensions/kube-flannel-ds-amd64 created
daemonset.extensions/kube-flannel-ds-arm64 created
daemonset.extensions/kube-flannel-ds-arm created
daemonset.extensions/kube-flannel-ds-ppc64le created
daemonset.extensions/kube-flannel-ds-s390x created
#flannel完全下載完后，查看kube-system組件的運行狀態，所有狀態都顯示Running表示正常
[Node 配置]
#忽略Swap錯誤
~]# vim /etc/sysconfig/kubelet
KUBELET_EXTRA_ARGS="--fail-swap-on=false"
#兩個Node節點加入到kubernetes集群中
~]# kubeadm join 192.168.1.118:6443 --token gx1knl.wts9qo4ebghwk242 --discovery-token-ca-cert-hash sha256:bd7bb24b445dc95f0571c501bdc4e82aa23fdc8a7194a571790923b7d4b10468 --ignore-preflight-errors=Swap
[preflight] Running pre-flight checks
[WARNING Swap]: running with swap on is not supported. Please disable swap
[WARNING SystemVerification]: this Docker version is not on the list of validated versions: 18.09.3. Latest validated version: 18.06
[discovery] Trying to connect to API Server "192.168.1.118:6443"
[discovery] Created cluster-info discovery client, requesting info from "https://192.168.1.118:6443"
[discovery] Requesting info from "https://192.168.1.118:6443" again to validate TLS against the pinned public key
[discovery] Cluster info signature and contents are valid and TLS certificate validates against pinned roots, will use API Server "192.168.1.118:6443"
[discovery] Successfully established connection with API Server "192.168.1.118:6443"
[join] Reading configuration from the cluster...
[join] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -oyaml'
[kubelet] Downloading configuration for the kubelet from the "kubelet-config-1.13" ConfigMap in the kube-system namespace
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet-start] Activating the kubelet service
[tlsbootstrap] Waiting for the kubelet to perform the TLS Bootstrap...
[patchnode] Uploading the CRI Socket information "/var/run/dockershim.sock" to the Node API object "n2" as an annotation
This node has joined the cluster: #看到這個信息表示這個節點已經加入到集群中了
* Certificate signing request was sent to apiserver and a response was received.
* The Kubelet was informed of the new secure connection details.
Run 'kubectl get nodes' on the master to see this node join the cluster.
~]# mkdir -p $HOME/.kube
#所有 Node節點都加入到集群以后，在Mstar主機上就能看到所有節點狀態已經為Ready就緒狀態
#Master傳輸認證文件到Node節點，Node連接集群必須要需要證書認證
~]# scp /etc/kubernetes/admin.conf root@192.168.1.155:/root/.kube/config
~]# scp /etc/kubernetes/admin.conf root@192.168.1.156:/root/.kube/config
Kubernets集群搭建完畢