第五十三天 Ansible variables

1.什么是变量

以一个固定的字符串，表示一个不固定的值。我们称之变量。

2.定义变量

1.在playbook中定义变量

vars 关键字

[root@manager project1]# vim f2.yml 

- hosts: webservers
  vars:
    - file_name: playbook_vars
  tasks:

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

vars_file：它属于一种共享式的方式

1570755668515.png

[root@manager project1]# vim f2.yml 

- hosts: webservers
  #引用变量文件./vars_file.yml
  vars_files: ./vars_file.yml

  tasks:

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


[root@manager project1]# vim ./vars_file.yml 

web_packages: httpd
ftp_packages: vsftpd

2.在inventory主机清单中定义变量

多重定义变量的方式优先级

1.在playbook中定义vars变量
2.在playbook中定义vars_file 变量
3.在inventory主机定义变量
4.在inventory主机组定义变量
5.在host_vars中定义变量
6.在group_vars中定义变量
7.通过命令传参的方式定义变量

命令传参的优先级最高
其次是playbook中vars_file
在其次playbook中vars

然后是inventory单个主机host_vars
再然后hosts主机清单中单个主机变量

然后是inventory主机组group_vars
再其次是group_vars/all
最后是hosts主机清单中的主机组变量

1.在清单文件中直接定义 hosts文件定义

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

2.创建host_vars group_vars 目录

host_vars   固定目录，用于存放主机变量
group_vars  固定目录，用于存放主机组变量

定义单个主机变量（能分辨对不同的主机定义变量）
[root@manager project1]# vim host_vars/172.16.1.7
host_vars_name: 172.16.1.7
[root@manager project1]# vim host_vars/172.16.1.8
host_vars_name: 172.16.1.8


[root@manager project1]# vim f4.yml 

- hosts: webservers
  tasks:

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


定义主机组变量（可以定义单个主机组设定变量，其他组无法使用）
[root@manager project1]# vim group_vars/webservers 
group_host_vars: webservers

[root@manager project1]# vim f5.yml 

- hosts: webservers
  tasks:
    - name: Create New File {{ group_host_vars }}
      file:
        path: /opt/{{ group_host_vars }}
        state: touch


定义主机组变量（定义所有主机组变量，所有主机都可以使用）

[root@manager project1]# vim group_vars/all 
group_host_vars: all

3.通过外置传参定义变量

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

3.变量注册

register关键字可以将某个task任务结果存储至变量中，最后使用debug输出变量内容，可以用于后续排障

[root@manager project1]# vim 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 }}"

4.facts变量

Ansible facts实在被关了主机上通过ansible自动采集发现的变量。facts包含每台特定的主机信息。比如，被控端主机的主机名、IP地址、系统版本、CPU数量、内存状态、磁盘状态等

facts使用场景

1.通过facts变量检查被控端硬件cpu信息，从而生成不同的Nginx配置文件

2.通过facts变量检测被控端主机名称信息，从而生成不同的Zabbix配置文件

3.通过facts变量检查被控端内存状态信息，从而生成不同的memcached的配置文件

……………………

1.facts基本用法，比如获取被控端的主机名与IP地址，然后通过debug输出

[root@manager project1]# vim f9.yml

- hosts: webservers
  tasks:
    - name: Output variables ansible facts
      debug:
        msg: >
         this default IPv4 address " {{ ansible_fqdn }} " is " {{ ansible_default_ipv4.address }} "

1.根据主机的cpu信息，生成不同的配置

[root@manager project1]# vim f10.yml 

- hosts: webservers
  tasks:

    - name: Config Nginx.conf
      template:
        src: ./file/nginx.conf.j2
        dest: /etc/nginx/nginx.conf


[root@manager project1]# vim file/nginx.conf.j2 

user www;
worker_processes  {{ ansible_processor_vcpus }};

error_log  /var/log/nginx/error.log notice;
pid        /var/run/nginx.pid;

events {
    worker_connections  1024;
}


http {
    include       /etc/nginx/mime.types;
    default_type  application/octet-stream;
    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';

        access_log /var/log/nginx/access.log main;

    sendfile        on;
    #tcp_nopush     on;
    keepalive_timeout  65;
    #gzip  on;
    include /etc/nginx/conf.d/*.conf;
}


    
#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=""


1.根据cpu
2.根据内存
3.根据主机名
4.Redis配置文件     bind本地地址
5.操作系统不统一

        变量可以进行运算  + - * // 
        
        
        
        
#1.定义变量
    playbook
        vars            私有
        vars_files      共享
    inventory
        host_vars   
        group_vars
            group_vars/group_name
            group_vars/all
    外置传参
        -e
#2.测试优先级
    在不改变playbook变量的情况下,使用新的值测试.

#3.变量注册register
    1.将任务执行的结果存储至特定的变量中
    2.可以使用debug模块将变量进行打印输出
    
    python: 字典
    json 格式化数据
    {
        k1: v1
        k2: v2
    }



#4.facts 



[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 }}"

1570768637521.png

Ansible 流程控制

8.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 )

9.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

10.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。

变量->facts-->判断-->循环

• 1.安装Rsyncd服务 (循环)
• 2.安装Redis (bind 本地IP地址) facts
• 3.安装NFS (配置文件,创建目录,客户端挂载) 变量