03 实战 Ansible-Playbook之初始化服务器

批量初始化服务器

初始化步骤

• 配置ssh密钥认证
• 远程配置主机名
• 控制远程主机互相添加HOSTS解析
• 配置远程主机的yum源以及一些软件
• 时间同步配置
• 关闭selinux/iptables
• 修改sshd配置

配置ssh密钥认证

• 在主控节点的/etc/ansible/hosts配置节点

$ vim /etc/ansible/hosts
[new]
192.168.56.12
192.168.56.13

在控制节点配置到受控节点的ssh认证方式

# 主控节点执行
$ ssh-keygen -t rsa -f ~/.ssh/id_rsa -N ''
$ for host in 192.168.56.{11..12};do
ssh-keyscan $host >> ~/.ssh/hnow_hosts 2> /dev/null
sshpass -p '123456' ssh-copy-id root@$host &> /dev/null
done

将上面的方案playbook化：

---
- name: config ssh connection
  hosts: new
  gather_facts: false
  tasks:
    - name: configure ssh connection
      shell: |
          ssh-keyscan {{inventory_hostname}} >> ~/.ssh/know_hosts
          sshpass -p '123456' ssh-copy-id root@{{inventory_hostname}} 

ansible命令执行模块

以下的四个模块不满足幂等性

• command：执行简单的shell命令
• shell： 和command相同，但支持管道富豪
• raw： 执行底层shell命令，通常在目标主机上安装python时才使用这个模块
• script： 在远程主机上执行脚本

以下命令具备幂等性：

• creates: 当指定的文件或者目录不存在时执行，存在不执行
• removes：当指定的文件或者目录不存在时不执行，存在执行

---
- name: modules use
  hosts: new
  gather_facts: false
  tasks:
      - name: use shell module
        shell: cp /tmp/my.cnf /etc/my.cnf
        args:
          creates: /etc/my.cnf
      - name: exec perl scripts
         script: /opt/script.pl
         args:
           executable: perl

重点

• connection: 连接方式（smart|ssh|paramiko|local|docker|winrm）,默认为smart表示只能选择ssh或者paramiko
• delegate_to: 只能定义在task级别上，效果和connection相似

---
- name: play1
  hosts: zabbix
  gather_facts: false
  tasks:
    - name: task 1
      debug:
        msg: "{{ inventory_hostname }} is executing task"
      delegate_to: localhost

authorized_key模块

特点：

• 分发ssh公钥
• 不负责主机认证阶段 前提需要配置好hosts下的ansible_passwd字段

[new]
192.168.56.11 ansible_hostname="centos7-node1"
192.168.56.12 ansible_hostname="centos7-node2"
[new:vars]
ansible_password="yeecallk8s"

分发认证配置

---
- name: "configure ssh connection"
  hosts: new
  gather_facts: false
  tasks:
    - authorized_key:
        key: "{{lookup('file','~/.ssh/id_rsa.pub')}}"
        state: present
        user: root

外部数据读取的方式：

• lookup() :支持从file，redis，etcd，pipe，vars，list，dict
  • fileglob: 支持统配文件名，file指定文件,pipe从命令执行结果中返回数据

---
- name: "fileglob and file task"
  hosts: new
  gather_facts: false
  tasks:
    - name: task1
      debug:
        msg: "filenames: {{ lookup('fileglob','/etc/*.conf')}}"
    - name: task2
      debug:
        msg: "filecontents: {{ lookup('file','/etc/hosts')}}

• query() : 统配文件读取，返回list格式

---
- name: "fileglob and files query"
  hosts: new
  gather_facts: false
  tasks:
    - name: "fileglob"
      debug:
        msg: "fileglob {{lookup('fileglob','/etc/*.conf')}}"
    - name: "fileglob wantlist"
      debug:
        msg: "fileglob wantlist {{lookup('fileglob','/etc/*.conf',wantlist=True)}}"
    - name: "query"
      debug:
        msg: "query {{q('fileglob','/etc/*.conf')}}"

设置主机名

使用的是hostname模块,会直接修改/etc/hostname 配置文件

---
- name: set hostname
  hosts: new
  gather_facts: false
  vars:
    hostnames:
      - host: 192.168.56.13
        name: centos7-node3
      - host: 192.168.56.14
        name: centos7-node4
  tasks:
    - name: set hostname
      hostname:
        name: "{{ item.name }}"
      when: item.host == inventory_hostname
      loop: "{{ hostnames }}"

vars变量设置注意：

• 设置在play级别，该play范围内的task都能访问这些变量，其他的play则无法访问
• 设置在task级别，只有该task范围内才能访问这个变量

---
- name: vars task1
  hosts: new
  gather_facts: false
  vars:
    - var1: "value1"
  tasks:
    - name: access value1
      debug:
        msg: "var1 in task1 {{var1}}"

- name: vars task2
  hosts: new
  gather_facts: false
  tasks:
    - name: can not access vars from task1
      debug:
        msg: var1
    - name: set and access var2 in this task
      debug:
        msg: var2
      vars:
        var2: "value2"
    - name: cant access var2
      debug:
        msg: var2

when条件判断

• 当when判断为true的时候执行任务，反之不执行

---
- name: when judge
  hosts: new
  gather_facts: false
  vars:
    - myname: "alex"
  tasks:
    - name: task skip
      debug:
        msg: "my name is {{myname}}"
      when: myname == "hello"   #这个判断条件是false的
    - name: task will execute
      debug:
        msg: "my name is {{myname}}"
      when: myname == "alex"

loop循环: 解决重复问题

• 未使用循环的例子

---
- name: make dirs for localhost
  hosts: localhost
  gather_facts: false
  tasks:
    - name: create test1
      file:
        path: /tmp/test1
        state: directory
    - name: create test2
      file:
        path: /tmp/test2
        state: directory

• 使用循环的例子

---
- name: mkdir loop
  hosts: localhost
  gather_facts: false
  tasks:
    - name: create test1,2 directory
      file:
        path: "{{item}}"
        state: directory
      loop:
        - /tmp/test01
        - /tmp/test02

互相添加hosts（DNS）主机名解析

互相添加指定hosts组的host之间的hosts解析

---
- name: add hosts DNS
  hosts: new
  gather_facts: false
  tasks:
    - name: add DNS
      lineinfile:
        path: /etc/hosts
        line: "{{item}} {{hostvars[item].ansible_hostname}}"
      when: item != inventory_hostname
      loop: "{{ play_hosts }}"

• lineinfile模块： 在源文件中插入，删除，替换行，跟sed类似

# 创建测试文件a.txt 
paragraph 1
first line in paragraph 1
second line in paragraph 1
paragraph 2
first line in paragraph 2
second line in paragraph 2

## lineinfile追加实例
---
- name: add line to a.txt
  hosts: localhost
  gather_facts: false
  tasks:
    - lineinfile:
        path: "a.txt"
        line: "append new line"
        state: absent     # 删除上面的line定义的行（append new line）


### 插入操作，定义在摸个行前或者行后新增（insertbefore,insertafter）
---
- name: lininfile demo for before and after insert
  hosts: localhost
  gather_facts: false
  tasks:
    - name: line infile
      lineinfile:
        path: "a.txt"
        line: "LINE1"
        insertbefore: '^para.* 2'
        firstmatch: yes
      lineinfile:
        path: "a.txt"
        line: "LINE2"
        insertafter: '^para.* 2'
        firstmatch: yes

• play_hosts和hostvars变量
  • inventory_hostname: 表示在主机inventory中定义的名称
  • play_hosts和hostvars: 是预定义变量，执行任务时可以直接拿出来使用，play_hosts相当于是new这个主机组里面的所有主机列表；
    • hostvars: 保存了所有目标主机的变量

- name: add DNS
      lineinfile:
        path: /etc/hosts
        line: "{{item}} {{hostvars[item].ansible_hostname}}"
      when: item != inventory_hostname
      loop: "{{ play_hosts }}"

配置yum源并下载安装软件

更换yum源，安装软件

---
- name: "init yum"
  hosts: new
  gather_facts: false
  tasks:
    - name: "backup old yum_repo"
      shell:
        cmd: "mkdir bak; mv *.repo bak"
        chdir: /etc/yum.repos.d
        creates: /etc/yum.repos.d/bak
    - name: "add new os repo and release repo"
      yum_repository:
        name: "{{item.name}}"
        description: "{{item.name}} repo"
        baseurl: "{{item.baseurl}}"
        file: "{{item.name}}"
        enabled: 1
        gpgcheck: 0
        reposdir: /etc/yum.repos.d
      loop:
        - name: os
          baseurl: "https://mirrors.tuna.tsinghua.edu.cn/centos/$releasever/os/$basearch"
        - name: epel
          baseurl: "https://mirrors.tuna.tsinghua.edu.cn/epel/$releasever/$basearch"
    - name: install pkgs
      yum:
        name: vim,net-tools,git-core,lrzsz,wget,curl,sysstat,iotop,gcc,gcc-c++,cmake,pcre,pcre-devel,zlib,zlib-devel,openssl,openssl-devel,vim,wget,telnet,setuptool,lrzsz,dos2unix,
net-tools,bind-utils,tree,screen,iftop,ntpdate,tree,lsof,iftop,iotop,sysstat,procps
        state: present

时间同步

使用ntpdate 同步时间

 ---
- name: sync time
  hosts: new
  gather_facts: false
  tasks:
    - name: install and sync time
      block:
        - name: install ntpdate
          yum:
            name: ntpdate
            state: present
        - name: ntpupdate to sync time
          shell: |
            ntpdate ntp1.aliyun.com
            hwclock -w

• block是组织了两个有关联性的任务

关闭selinux

命令行关闭和修改配置文件两种手段

---
---
- name: disable selinux
  hosts: new
  gather_facts: false
  tasks:
    - block:
        - name: disable selinux by command
          shell: setenforce 0
      
        - name: disable selinux by config
          lineinfile:
            path: /etc/selinux/config
            line: "SELINUX=disabled"
            regexp: '^SELINUX='
      ignore_errors: true

配置防火墙

---
- name: set firewalld
  hosts: new
  gather_facts: false
  tasks:
    - name: set iptables rule
      shell: |
        iptables-save > /tmp/iptables.bak$(date +"%F-%T")
        iptables -X
        iptables -F
        iptables -Z
        systemctl disable firewalld
        systemctl stop firewalld

配置sshd服务

• 需求：
  • 禁止root用户登陆
  • 不允许使用密码登陆

---
- name: "set sshd service"
  hosts: new
  gather_facts: false
  tasks:
    - name: backup old sshd config
      shell: |
        /usr/bin/cp -f {{path}} {{path}}.bak
      vars:
        - path: /etc/ssh/sshd_config
    - name: disable root login
      lineinfile:
        path: "/etc/ssh/sshd_config"
        line: "PermitRootLogin no"
        regexpr: '^PermitRootLogin'
      notify: "restart sshd"
    - name: disable passwd auth
      lineinfile:
        path: "/etc/ssh/sshd_config"
        line: "PasswordAuthentication no"
        regexp: '^PasswordAuthentication yes'
      notify: "restart sshd"
  handlers:
    - name: "restart sshd"
      service:
        name: sshd
        state: restarted

参考

推荐专栏：https://blog.51cto.com/cloumn/detail/83from_distribution=VQcJVApVVQwxUwIHVQYFDA 代码gitee：https://gitee.com/wanghui1234/ansible_repo.git