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-