Ubuntu 安装k8s 步骤如下：
1 修改 Ubuntu 配置
2 安装docker
3 安装kubeadm、kubectl以及kubelet
4 初始化master节点
5 将slave节点加入网络

1 修改 Ubuntu 配置

1.1 禁用 swap

它可以让服务器在内存吃满的情况下可以保持低效运行，而不是直接卡死。但是 k8s 的较新版本都要求关闭swap。

1.1.1 永久禁用 swap

vi /etc/fstab

root@ubuntu:~#sudo vim /etc/fstab
# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
# / was on /dev/sda1 during installation
UUID=4e0da007-738b-457b-a85b-068d8ae3f77a /               ext4    errors=remount-ro 0       1
#/swapfile                                 none            swap    sw              0       0
#/dev/fd0        /media/floppy0  auto    rw,user,noauto,exec,utf8 0       0
root@ubuntu:~#

重启系统

1.1.2 临时禁用 swap

使用swapoff -a命令即可，效果会在重启后消失。

sudo swapoff -a

1.1.3 查看禁用效果

top - 10:48:39 up  1:21,  2 users,  load average: 0.00, 0.00, 0.00
Tasks: 353 total,   1 running, 352 sleeping,   0 stopped,   0 zombie
%Cpu(s):  0.0 us,  0.0 sy,  0.0 ni,100.0 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st
MiB Mem :   1958.9 total,    196.5 free,   1133.6 used,    628.8 buff/cache
MiB Swap:      0.0 total,      0.0 free,      0.0 used.    640.6 avail Mem

   PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND
 18708 root      20   0 1414732  39140  17128 S   1.0   2.0   0:38.47 containerd
 18743 root      20   0       0      0      0 I   0.3   0.0   0:00.04 kworker/1:3-events
 30834 root      20   0   13280   8424   7284 S   0.3   0.4   0:00.13 sshd
 33073 root      20   0   12056   4180   3244 R   0.3   0.2   0:00.02 top
     1 root      20   0  168296  10052   5840 S   0.0   0.5   0:05.00 systemd
     2 root      20   0       0      0      0 S   0.0   0.0   0:00.02 kthreadd
     3 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 rcu_gp
     4 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 rcu_par_gp
     6 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 kworker/0:0H-kblockd
     9 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 mm_percpu_wq
    10 root      20   0       0      0      0 S   0.0   0.0   0:00.02 ksoftirqd/0
    11 root      20   0       0      0      0 I   0.0   0.0   0:00.76 rcu_sched
    12 root      rt   0       0      0      0 S   0.0   0.0   0:00.02 migration/0

效果如下说明禁用成功

1.2 Ubuntu 免密登录

Ubuntu 免密登录

2 安装 Docker

Ubuntu 安装 Docker

3 安装 K8s

sudo apt-get update && apt-get install -y apt-transport-https curl

添加 k8s 秘钥(二选一 选阿里)

# 谷歌
#curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add -
# 阿里
curl https://mirrors.aliyun.com/kubernetes/apt/doc/apt-key.gpg | apt-key add -

添加 k8s 镜像源(二选一 选阿里)

# 官方 镜像源
cat <<EOF >/etc/apt/sources.list.d/kubernetes.list
deb http://apt.kubernetes.io/ kubernetes-xenial main
EOF
# 阿里 镜像源
cat <<EOF >/etc/apt/sources.list.d/kubernetes.list
deb https://mirrors.aliyun.com/kubernetes/apt/ kubernetes-xenial main
EOF

更新源

sudo apt update

安装 kubeadm、kubectl以及kubelet

sudo apt install -y kubelet kubeadm kubectl

4 初始化master节点

后续更新

5 将slave节点加入网络

后续更新