Kubernetes 安装

安装docker（前提条件）

查看docker安装文档

关闭swap

swapoff -a
sed -ri 's/.*swap.*/#&/' /etc/fstab

禁用SELinux

setenforce 0                                                
sed -i 's/^SELINUX=enforcing$/SELINUX=disable/' /etc/selinux/config

修改安装源

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

CentOS 7流量无法正确路由问题

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

安装kubelet kubeadm kubectl

yum install -y kubelet-1.17.9 kubeadm-1.17.9 kubectl-1.17.9

设置kubelet开机启动

systemctl enable kubelet

启动kubelet

systemctl start kubelet

查看kubelet状态

systemctl status kubelet

kubeadm创建集群

kubeadm init \
--apiserver-advertise-address=192.168.1.201 \
--image-repository registry.cn-hangzhou.aliyuncs.com/google_containers \
--kubernetes-version v1.17.9 \
--service-cidr=192.168.2.0/16 \
--pod-network-cidr=192.168.3.0/16

初始化完成执行（master节点执行）

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

其他节点加入集群（node节点执行）

kubeadm join 10.0.2.15:6443 --token 8mgmlh.cgtgsp3samkvpksn --discovery-token-ca-cert-hash sha256:3c f99aa2e6bfc114c5490a7c6dffcf200b670af21c5a662c299b6de606023f85

安装pod网络插件

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

https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml无法访问，先下载文件

在执行下面的命令：

kubectl apply -f kube-flannel.yml

注意：加入节点之前，请先安装pod网络插件

常见问题

kube-flannel.yml文件中有2个镜像下载非常慢，会导致节点无法ready
get pods -n kube-system