一、Kubernetes安装

1. 环境准备

1.1 主机名解析

在所有节点添加主机名称解析记录

- hosts: k8sserver
  tasks:
    - name: add k8s servers  hosts
      lineinfile:
        path: /etc/hosts
        line: "{
  { item }}"
      loop:
        - 172.31.4.21 master01
        - 172.31.4.24 node01
        - 172.31.4.25 node02
        - 172.31.4.26 node03

1.2 关闭selinux、关闭防火墙

- name: Disable Selinux
  selinux:
    state: disabled
    
- name: Disable Firewalld
  systemd:
    name: firewalld
    state: stopped
    enabled: no

1.3 关闭swap，禁止k8s使用swap

    - name: off swap
      shell:
        cmd: swapoff -a && sed -ri 's/.*swap.*/#&/' /etc/fstab

1.4 内核优化

1. 加载 br_netfilter 模块

 modprobe br_netfilter

2. 创建/etc/sysctl.d/k8s.conf 文件，添加如下内容

    - name: Load br_netfilter Module
      shell:
        cmd: modprobe br_netfilter

    - name: Enabled net.bridge.bridge-nf-call-ip6tables
      sysctl:
        name: net.bridge.bridge-nf-call-ip6tables
        value: '1'
        sysctl_set: yes

    - name: Enabled net.bridge.bridge-nf-call-iptables 
      sysctl: 
        name: net.bridge.bridge-nf-call-iptables
        value: '1'
        sysctl_set: yes

    - name: Enabled  net.ipv4.ip_forward
      sysctl:
        name: net.ipv4.ip_forward
        value: '1'
        sysctl_set: yes

    - name: Disabled vm.swappiness
      sysctl:
        name: vm.swappiness
        value: '0'
        sysctl_set: yes

1.5 安装IPVS

1. 为了方便查看ivps规则，需要安装管理工具ipvsadm，在所有节点执行

    - name: Install IPVS
      yum:
        name: "{
  { item }}"
        state: present
      loop:
        - ipset
        - ipvsadm

2. 加载ipvs模块，在所有节点执行

$ cat ipvs.modules 
#!/bin/bash
modprobe -- ip_vs
modprobe -- ip_vs_rr
modprobe -- ip_vs_wrr
modprobe -- ip_vs_sh
modprobe -- nf_co