1.什么是变量

以一个固定的字符串，表示一个不固定的值

2.定义变量

1.在playbook中定义变量
vars关键字

[root@manager project1]# cat f2.yml 
- hosts: webservers
  vars:
    - file_name: playbook_vars

  tasks:
    - name: Create New File
      file:
        path: /tmp/{{ file_name }}
        state: touch

vars_file 属于一种共享的方式

[root@manager project1]# cat vars_file.yml 
web_packages: httpd
ftp_packages: vsftpd

[root@manager project1]# cat f2.yml 
- hosts: webservers
  vars:
    - file_name: playbook_vars

 #调用共享vars_file文件,只不过刚好文件名叫vars_file
  vars_files: ./vars_file.yml

  tasks:
    - name: Create New File
      file:
        path: /tmp/{{ file_name }}
        state: touch

    - name: Installed Packages {{ web_packages }}
      yum:
        name: "{{ web_packages }}"
        state: present

2.在inventory主机清单中定义变量
清单文件中直接定义 host文件定义

[webservers]
172.16.1.7
172.16.1.8 
[webservers:vars]
file_name=hostsfile_group_vars

创建host_vars group_vars目录

[root@manager project1]# mkdir host_vars    #单个主机
[root@manager project1]# mkdir group_vars   #主机组


#1.单个主机定义和使用方式 (host_vars能分别对不同的主机定义变量)
[root@manager project1]# cat host_vars/172.16.1.7 
host_vars_name: 172.16.1.7

[root@manager project1]# cat host_vars/172.16.1.8 
host_vars_name: 172.16.1.8

[root@manager project1]# cat f4.yml 
- hosts: webservers

  tasks:
    - name: Create New File
      file:
        path: /opt/{{ host_vars_name }}
        state: touch

#2.针对主机组定义的方式 
#给指定的webserver组设定变量.其他组主机无法使用该变量
[root@manager project1]# cat group_vars/webservers 
group_host_vars: webservers

[root@manager project1]# cat f5.yml 
- hosts: webservers
  tasks:
    - name: Create New File {{ group_host_vars }}
      file:
        path:  /opt/{{ group_host_vars }}
        state: touch


#3.针对主机组定义的方式  (给所有的主机和主机组设定变量)
[root@manager project1]# cat group_vars/all 
group_host_vars: all

[root@manager project1]# cat f5.yml 
- hosts: webservers
  tasks:
    - name: Create New File {{ group_host_vars }}
      file:
        path:  /opt/{{ group_host_vars }}
        state: touch

3.通过外置传参定义变量 -e

[root@manager project1]# ansible-playbook -i hosts f6.yml  -e "web_vars=123"

3.变量冲突，优先级

变量优先级由高到低：
1>外置传参
2>playbook
    vars_files(共享)
    vars（私有）
3>host_vars
4>group_vars/group_name
5>group_vars/all

4.变量注册

[root@manager project1]# cat f8.yml 
- hosts: webservers
  tasks:
        # System_Status=$(netstat -lntp)
    - name: Get Network Status
      shell: netstat -lntp | grep "nginx"
      register: System_Status

        # echo "$System_Status"
    - name: Debug output Variables
      debug:
        msg: "{{ System_Status.stdout_lines }}"

5.facts变量

#1.根据主机的cpu信息,生成不同的配置.
    A: 1核心    work_process 1;
    B: 2核心    work_process 2;
    
#2.根据主机名称设定不同配置文件
    zabbix_agent
        Server:   ===> 指向172.16.1.61
        Hostname:      web01   web02

[root@manager project1]# cat ./file/zabbix_agent.conf.j2 
Server={{ zabbix_server_ip }}
ServerActive={{ zabbix_server_ip }}
Hostname={{ ansible_hostname }}

[root@manager project1]# cat f11.yml 
- hosts: webservers
  vars:
    - zabbix_server_ip: 172.16.1.61
  tasks:
    - name: Configure zabbix-agent.conf
      template:
        src: ./file/zabbix_agent.conf.j2
        dest: /tmp/zabbix-agent.conf
        
        
#3.根据主机的内存生成不同的配置文件,memcached
[root@manager project1]# cat f12.yml 
- hosts: webservers
  tasks:
    - name: Installed Memcached Server
      yum:
        name: memcached
        state: present

    - name: Configure Memcached Server
      template:
        src: ./file/memcached.j2
        dest: /etc/sysconfig/memcached
      notify: Restart Memcached Server

    - name: System Memcached Server
      systemd:
        name: memcached
        state: started
        enabled: yes

  handlers:
    - name: Restart Memcached Server
      systemd:
        name: memcached
        state: restarted

[root@manager project1]# cat file/memcached.j2 
PORT="11211"
USER="memcached"
MAXCONN="1024"
CACHESIZE="{{ ansible_memtotal_mb //2 }}"
OPTIONS=""



#4facts
[root@manager project1]# cat f13.yml 
- hosts: webservers
  tasks:
    - name: RANDOM
      shell:  echo "$RANDOM"
      register: System_SJ

    - name: Debug 
      debug:
        msg: "web_{{ System_SJ.stdout }}"

#1.提取facts变量中的IP地址   mac地址  UUID 等等  只要唯一
    ansible_default_ipv4.address
[root@manager project1]# cat f14.yml 
- hosts: webservers
  tasks:

    - name: Debug 
      debug:
        msg: "web_{{ ansible_default_ipv4.address }}"

image.png

ansible流程控制

1.判断语句

• 1.centos和ubuntu系统都需要安装httpd, 判断系统.
• 2.安装软件仓库,只有web组的安装webtatic其他的主机全部跳过.
• 3.TASK任务, TASK1任务执行成功,才会执行TASK2

#根据不同的系统,安装不同的服务
- hosts: webservers
  tasks:
    - name: CentOS Installed Httpd Server
      yum:
        name: httpd
        state: present
      when: ( ansible_distribution == "CentOS" )

    - name: Ubuntu Installed Httpd Server
      yum:
        name: httpd2
        state: present
      when: ( ansible_distribution == "Ubuntu" )
      
[root@manager project1]# cat f16.yml 
- hosts: all
  tasks:
  - name: Add Nginx Yum Repository
    yum_repository:
      name: nginx
      description: Nginx Repository
      baseurl: http://nginx.org/packages/centos/7/$basearch/
    when: ( ansible_hostname is match ("web*"))


[root@manager project1]# cat f17.yml 
- hosts: webservers
  tasks:

    - name: Check Httpd Server
      command: systemctl is-active httpd
      register: Check_Httpd
      ignore_errors: yes

    #判断Check_Httpd.rc是否等于0,如果为0则执行任务,否则不执行
    - name: Restart Httpd Server
      systemd:
        name: httpd
        state: restarted
      when: ( Check_Httpd.rc == 0 )

2.循环语句

#一次启动多个服务
[root@manager project1]# cat f18.yml 
- hosts: webservers
  tasks:
    - name: Systemd Nginx Status
      systemd:
        name: "{{ item }}"    #调用的变量也不变,也是固定
        state: started

    #固定的语法格式
      with_items:
        - nginx
        - php-fpm


#一次拷贝多个文件
[root@manager project1]# cat f19.yml
- hosts: webservers
  tasks:
    - name: Configure nginx.conf
      copy:
        src: '{{ item.src }}'
        dest: '{{ item.dest }}'
        mode: '{{ item.mode }}'
      with_items:
        - { src: ./file/nginx.conf.j2, dest: /etc/nginx/nginx.conf, mode: '0644' }
        - { src: ./file/kold.oldxu.com.conf.j2, dest: /etc/nginx/conf.d/kold.oldxu.com.conf, mode: '0600' }



#创建多个用户,一次创建多个? 3个用户  TASK
[root@manager project1]# cat f20.yml 
- hosts: webservers
  tasks:
    - name: Create User
      user:
        name: "{{ item }}"

      with_items:
        - test1
        - test2
        - test3
        - test4


#1.创建tt1 --> bin  tt2 -->root tt3 --->adm   附加组
[root@manager project1]# cat  f20.yml 
- hosts: webservers
  tasks:
    - name: Create User
      user:
        name: "{{ item.name }}"
        groups: "{{ item.groups }}"

      with_items:
        - { name: tt1, groups: bin }
        - { name: tt2, groups: root }
        - { name: tt3, groups: adm }
        
        
        
1.标准循环                   --->居多
    item
    with_items:
       - test
2.字典循环:                   --->居多
    itme.name
    with_items:
        - { name: test }


3.变量循环
- hosts: webservers
  tasks:
    - name: ensure a list of packages installed
      yum: name={{ packages }} state=present
      vars:
        packages:
          - httpd
          - httpd-tools

3.handlers

[root@manager project1]# cat f22.yml 
- hosts: webservers
  tasks:

    - name: Installed Nginx and PHP Packages
      yum:
        name: nginx
        state: present

    - name: Configure nginx.conf 
      template:
        src: ./file/nginx.conf.j2
        dest: /etc/nginx/nginx.conf
      #监控-->changed状态-->通知-->handlers--->name-->Restart Nginx Server
      notify: Restart Nginx Server
      #notify:
      #  - Restart Nginx Server
      #  - Restart php Server

    - name: Systemd Nginx Server
      systemd:
        name: nginx
        state: started
        enabled: yes

#当nginx或php配置文件发生变更才会触发此操作
  handlers:
    - name: Restart Nginx Server
      systemd:
        name: nginx
        state: restarted


#3.handlers注意事项
    1.无论多少个task通知了相同的handlers，handlers仅会在所有tasks结束后运行一次。
    2.只有task发生改变了才会通知handlers，没有改变则不会触发handlers.
    3.不能使用handlers替代tasks、因为handlers是一个特殊的tasks。