使用kubeadm安装kubernetes

安装kubenetes的方法有多种，本文将介绍如何用kubeadm安装kubernetes。

一 node准备

1 /etc/hosts文件

192.168.235.133 kube01
192.168.235.134 kube02
192.168.235.135 kube03

2 关闭swap

swapoff -a 

注释/etc/fstab中的swap挂载

#/dev/mapper/centos-swap swap swap defaults 0 0

 3 修改内核参数

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

4 安装docker

yum install docker -y
systemctl enable docker
systemctl start docker

5 关闭firewalld

systemctl stop firewalld.service

systemctl disable firewalld.service

二 安装kubeadm

1 增加yum的repo

cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://packages.cloud.google.com/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
EOF

2 安装

setenforce 0
sed -i 's/SELINUX=enforcing/SELINUX=disabled/' /etc/selinux/config
yum install -y kubelet kubeadm kubectl
systemctl enable kubelet && systemctl start kubelet

三 用kubeadm安装kubenetes集群

1 用kubeadm初始化

在master节点运行：

kubeadm init 
 --pod-network-cidr=10.244.0.0/16 
 --apiserver-advertise-address=192.168.235.133

安装完成：

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 192.168.235.133:6443 --token 8ojndu.qaow6tuo95psar5g --discovery-token-ca-cert-hash sha256:79c955c758bd76f02335c33540f3880039bcf9aa137c9b67366a990ccefbaead

2 安装Pod netwok

mkdir -p ~/k8s/
cd ~/k8s
wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
kubectl apply -f  kube-flannel.yml

 3 将node2和node3加入到集群中

kubeadm join 192.168.235.133:6443 --token 8ojndu.qaow6tuo95psar5g --discovery-token-ca-cert-hash sha256:79c955c758bd76f02335c33540f3880039bcf9aa137c9b67366a990ccefbaead

 在master节点上观察：

[root@kube01 k8s]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
kube01 Ready master 23m v1.10.2
kube02 Ready <none> 5m v1.10.2
kube03 Ready <none> 5m v1.10.2

总结：

使用kubeadm可以方便的安装kubernetes集群。