安装环境： CentOS 7.5，Docker CE 17.03
(本想写1.11.0版本的安装，由于遇到问题，退到1.10.5版本了)

1. 主机配置
关闭防火墙

sudo systemctl stop firewalld
sudo systemctl disable firewalld

关闭swap

sudo swapoff -a
sudo sed -i '/ swap / s/^\(.*\)$/#\1/g' /etc/fstab

关闭SELinux

sudo setenforce 0

设置内核参数

cat <<EOF > /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
sysctl --system

添加host记录，如有dns记录则不需要

cat >> /etc/hosts << EOF
192.168.1.101	k8s1 k8s1.test.local
192.168.1.102	k8s2 k8s2.test.local
192.168.1.103	k8s3 k8s3.test.local
EOF

2. 下载Kubernetes镜像
从mirrorgooglecontainers源下载镜像

docker pull mirrorgooglecontainers/kube-apiserver-amd64:v1.10.5
docker pull mirrorgooglecontainers/kube-scheduler-amd64:v1.10.5
docker pull mirrorgooglecontainers/kube-proxy-amd64:v1.10.5
docker pull mirrorgooglecontainers/kube-controller-manager-amd64:v1.10.5
docker pull mirrorgooglecontainers/pause-amd64:3.1
docker pull mirrorgooglecontainers/k8s-dns-kube-dns-amd64:1.14.8
docker pull mirrorgooglecontainers/k8s-dns-dnsmasq-nanny-amd64:1.14.8
docker pull mirrorgooglecontainers/k8s-dns-sidecar-amd64:1.14.8
docker pull quay.io/coreos/etcd:v3.1.12
docker pull quay.io/coreos/flannel:v0.10.0-amd64
docker pull coredns/coredns:1.0.6

将镜像标记为k8s.gcr.io的名称

docker tag mirrorgooglecontainers/kube-apiserver-amd64:v1.10.5 k8s.gcr.io/kube-apiserver-amd64:v1.10.5
docker tag mirrorgooglecontainers/kube-scheduler-amd64:v1.10.5 k8s.gcr.io/kube-scheduler-amd64:v1.10.5
docker tag mirrorgooglecontainers/kube-proxy-amd64:v1.10.5 k8s.gcr.io/kube-proxy-amd64:v1.10.5
docker tag mirrorgooglecontainers/kube-controller-manager-amd64:v1.10.5 k8s.gcr.io/kube-controller-manager-amd64:v1.10.5
docker tag mirrorgooglecontainers/pause-amd64:3.1 k8s.gcr.io/pause-amd64:3.1
docker tag mirrorgooglecontainers/k8s-dns-kube-dns-amd64:1.14.8 k8s.gcr.io/k8s-dns-kube-dns-amd64:1.14.8
docker tag mirrorgooglecontainers/k8s-dns-dnsmasq-nanny-amd64:1.14.8 k8s.gcr.io/k8s-dns-dnsmasq-nanny-amd64:1.14.8
docker tag mirrorgooglecontainers/k8s-dns-sidecar-amd64:1.14.8 k8s.gcr.io/k8s-dns-sidecar-amd64:1.14.8
docker tag quay.io/coreos/etcd:v3.1.12 k8s.gcr.io/etcd-amd64:3.1.12

删除无用镜像名

docker images | grep mirrorgooglecontainers | awk '{print "docker rmi "$1":"$2}' | sh

安装、配置kubelet

cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF
yum install -y kubelet-1.10.5 kubeadm-1.10.5 kubectl-1.10.5
systemctl enable kubelet
sed -i "s/cgroup-driver=systemd/cgroup-driver=cgroupfs/g" /etc/systemd/system/kubelet.service.d/10-kubeadm.conf
systemctl daemon-reload
systemctl start kubelet

安装bash自动补全

yum install bash-completion -y
echo "source <(kubectl completion bash)" >> ~/.bashrc

3. 初始化k8s集群

kubeadm init --kubernetes-version v1.10.5 --token-ttl 0 --pod-network-cidr 10.244.0.0/16

指定kubernetes-version版本，由于有墙
token-ttl默认有效为24小时，改为0为永久有效
设置pod-network-cidr为flannel做准备

可以在初始化集群时使用CoreDNS代替kube-dns

kubeadm init --kubernetes-version v1.10.5 --token-ttl 0 \
--pod-network-cidr 10.244.0.0/16 --feature-gates CoreDNS=true

mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

如果是root用户也可以使用以下命令

export KUBECONFIG=/etc/kubernetes/admin.conf

配置flannel网络插件

curl -O https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
kubectl apply -f kube-flannel.yml

4. 确认kubernetes运行状态

kubectl get pods --all-namespaces

所有容器都运行时即部署完成

NAMESPACE     NAME                                    READY     STATUS    RESTARTS   AGE
kube-system   etcd-k8s1                               1/1       Running   1          6m
kube-system   kube-apiserver-k8s1                     1/1       Running   1          6m
kube-system   kube-controller-manager-k8s1            1/1       Running   1          6m
kube-system   kube-dns-86f4d74b45-lmcqv               3/3       Running   3          6m
kube-system   kube-flannel-ds-amd64-g6g66             1/1       Running   1          6m
kube-system   kube-proxy-rqnhh                        1/1       Running   1          6m
kube-system   kube-scheduler-k8s1                     1/1       Running   1          6m

5. 加入Node节点
Node节点的配置与Master基本相同（参见1、2节），只是所需的docker image少一些，只需要kube-proxy-amd64:v1.10.5、pause-amd64:3.1和flannel:v0.10.0-amd64(如果需要)

docker pull mirrorgooglecontainers/kube-proxy-amd64:v1.10.5
docker pull mirrorgooglecontainers/pause-amd64:3.1
docker pull quay.io/coreos/flannel:v0.10.0-amd64
docker tag mirrorgooglecontainers/kube-proxy-amd64:v1.10.5 k8s.gcr.io/kube-proxy-amd64:v1.10.5
docker tag mirrorgooglecontainers/pause-amd64:3.1 k8s.gcr.io/pause-amd64:3.1
docker images | grep mirrorgooglecontainers | awk '{print "docker rmi "$1":"$2}' | sh

然后使用kubeadm join加入k8s集群，该命令会在Master执行kubeadm init最后生成，如果没有记录下来可用以下命令生成

kubeadm token create --print-join-command

再使用kubectl get node命令确认节点加入情况

NAME              STATUS    ROLES     AGE       VERSION
k8s1.test.local   Ready     master    5m        v1.10.5
k8s2.test.local   Ready     <none>    3m        v1.10.5
k8s3.test.local   Ready     <none>    3m        v1.10.5