ubuntu18 安装单机k8s v1.18.2
背景
当我们需要对k8s进行二次开发时，k8s环境是必须的，那么在ubuntu上部署单机k8s是最方便的，便于开发调试
系统准备
本人用的是Ubuntu18，以下以此为例
部署之前，最好切换至root用户，方便操作
sfeng@sfeng-virtual-machine:~$ sudo passwd root
Enter new UNIX password: // 输入root密码
Retype new UNIX password: // 重复输入
passwd: password updated successfully
sfeng@sfeng-virtual-machine:~$ su - root
Password: // 输入root密码
系统初始化
sudo ufw disable // 关闭防火墙
sudo systemctl disable ufw // 永久关闭防火墙
sudo swapoff -a // 关闭swap
sed -ri 's/.*swap.*/#&/' /etc/fstab // 永久关闭swap
ubuntu系统默认没有安装selinux
// 更换国内镜像源
cp /etc/apt/sources.list /etc/apt/sources.list.bak
sed -i 's@http://cn.mirrors.ustc.edu.cn/ubuntu/@https://mirrors.tuna.tsinghua.edu.cn/ubuntu/@g' /etc/apt/sources.list
apt update
添加k8s安装秘钥
sudo apt update && sudo apt install -y apt-transport-https curl
curl -s https://mirrors.aliyun.com/kubernetes/apt/doc/apt-key.gpg | sudo apt-key add -
安装docker
curl -fsSL get.docker.com -o get-docker.sh
sudo sh get-docker.sh --mirror Aliyun
docker run hello-world // 验证docker是否安装完成
配置k8s源
sudo touch /etc/apt/sources.list.d/kubernetes.list
这里选择阿里云的源
sudo echo "deb https://mirrors.aliyun.com/kubernetes/apt/ kubernetes-xenial main" >> /etc/apt/sources.list.d/kubernetes.list
安装kubelet，kubeadm，kubectl
sudo apt-get update
// 这里带上版本号，防止后续部署报错版本不一致问题
sudo apt install -y kubelet=1.18.2-00
sudo apt install -y kubeadm=1.18.2-00
sudo apt install -y kubectl=1.18.2-00
// 保持版本取消自动更新，这里也可以省略
sudo apt-mark hold kubelet kubeadm kubectl
kubeadm 初始化
sudo kubeadm init --image-repository registry.aliyuncs.com/google_containers --kubernetes-version v1.18.2 --pod-network-cidr=10.240.0.0/16
等待出现以下信息，则说明初始化成功
// ...
Your Kubernetes control-plane 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/>
Then you can join any number of worker nodes by running the following on each as root:
kubeadm join 机器IP:6443 --token q1guce.z76o2a2bb65vhd0u \\
--discovery-token-ca-cert-hash sha256:2a57a27853c66d608bc544742b57602a21d47c3d09fe58eef15258946d4341c0
配置非 root 的操作
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
coredns 问题解决
这时候node 状态还是NotReady，因为网络插件还没有安装，这里安装calico
kubectl apply -f <https://docs.projectcalico.org/v3.10/manifests/calico.yaml>
安装成功后结果如下
root@sfeng-virtual-machine:~# kubectl get node
NAME STATUS ROLES AGE VERSION
sfeng-virtual-machine Ready master 28m v1.18.2
root@sfeng-virtual-machine:~# kubectl get pods --all-namespaces -o wide
NAMESPACE NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
kube-system calico-kube-controllers-57546b46d6-hfgx2 1/1 Running 0 23m 192.168.109.129 sfeng-virtual-machine <none> <none>
kube-system calico-node-kpx4p 1/1 Running 0 23m 192.168.57.23 sfeng-virtual-machine <none> <none>
kube-system coredns-7ff77c879f-gjgjb 1/1 Running 0 28m 192.168.109.130 sfeng-virtual-machine <none> <none>
kube-system coredns-7ff77c879f-qq6pz 1/1 Running 0 28m 192.168.109.131 sfeng-virtual-machine <none> <none>
kube-system etcd-sfeng-virtual-machine 1/1 Running 0 28m 192.168.57.23 sfeng-virtual-machine <none> <none>
kube-system kube-apiserver-sfeng-virtual-machine 1/1 Running 0 28m 192.168.57.23 sfeng-virtual-machine <none> <none>
kube-system kube-controller-manager-sfeng-virtual-machine 1/1 Running 0 28m 192.168.57.23 sfeng-virtual-machine <none> <none>
kube-system kube-proxy-jzfts 1/1 Running 0 28m 192.168.57.23 sfeng-virtual-machine <none> <none>
kube-system kube-scheduler-sfeng-virtual-machine 1/1 Running 0 28m 192.168.57.23 sfeng-virtual-machine <none> <none>
去掉master污点
// 这样master就能作为计算节点了哈，不然部署单机也没有意义
kubectl taint nodes --all node-role.kubernetes.io/master-
