ansible

ansible playbook用法

playbook作为ansible重要的企业实战解决方案。

playbook 基本使用

创建playbook文件

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touch playbooktest.yml
vim playbooktest.yml

编写playbook

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---
- hosts: websrvs
  remote_user: root

  task: 
    - name: hello
      command: hostname

执行playbook
ansible-playbook playbooktest.yml

palybook构成

palybook采用YAML语言编写，有多个剧本组成，每个剧本由若干个task组成，每个task调用不同的模块，最终在目标机器上执行。ansible playbook相当于linux shell脚本。
yaml.org 查看更多的语法详情

playbook之Hosts

第一种编写方式

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---
- hosts: websrvs
  remote_user: root

  tasks:
    - name: create new file
      file: name=/data/newfile state=touch
    - name: create a new user
      user: name=test2 system=yes
    - name: insall package
      yum: name=httpd
    - name: copy files
      copy: src=/var/www/html/index.html

第二种编写方式

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---
- hosts: websrvs
  remote_user: root

  tasks:
    - name: create new file
      file: 
        name: /data/newfile
        state: touch

    - name: create a new user
      user:
        name: test2
        system: yes

    - name: insall package
      yum: 
        name:httpd
    
    - name: copy files
      copy:
        src:/var/www/html/index.html

只进行检查，不真正执行
ansible-playbook test.yml --check
ansible-playbook -C test.yml

handlers和notify结合使用条件触发

  • handlers相当于一个触发器，配合notify使用。
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    ---
    - hosts: websrvs
      remote_user: root

      tasks:
         - name: install httpd
           yum: name=httpd
           tags: installed

         - name: config file
           copy: src=files/httpd.conf dest=/etc/httpd/conf/ backup=yes
           notify: 
            - restart service
            - check the nginx process
        
         - name: restart httpd
           service: name=httpd state=start enableed=yes
           tags: rshttpd

      handlers:
        - name: restart service
          service: name=httpd state=restarted
        - name: check the nginx process
          shell: killall -0 nginix> /tmp/nginx.log

ansible tags的使用

添加tags后，可以通过tags调用，通过指定标签执行特定task.
ansible-playbook -t installed,rshttpd httpd.yml

playbook中变量的使用

ansible变量只能数字字母下划线组成，且只能字母开头，包括系统变量和自定义变量。

  • 查询某个关键字的系统变量。
    ansible websrvs -m setup -a 'filter=ansible_fqdn'

  • 引用外部的变量

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    ---
    - hosts: websrvs
      remote_user: root

      tasks:
        - name: create new file
          file: 
            name: /data/newfile
            state: touch

        - name: create a new user
          user:
            name: test2
            system: yes

        - name: insall package
          yum: 
            name: {{ pkname }}

执行playbook并通过-e传入变量
ansbible-playbook app.yml -e 'pkname=httpd pkname2=vbss'

  • 在playbook中定义变量
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    ---
    - hosts: websrvs
      remote_user: root
      vars:
        - pkname1: httpd
        - pkname2: vbs
         
      tasks:
        - name: create new file
          file: 
            name: /data/newfile
            state: touch

        - name: insall package
          yum: 
            name: {{ pkname }}

执行playbook自动引用内部定义的变量
ansbible-playbook app.yml

  • 在ansible的hosts文件中定义变量，
    /etc/ansible/hosts
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    [webserver]
    192.168.1.2 http_port=81
    192.168.1.4 http_port=82

playbook引用hosts中的变量

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---
- hosts: websrvs
  remote_user: root
  vars:
    - pkname1: httpd
    - pkname2: vbs
  
  tasks:
    - name: set hostname
      hostname: name=wwww.{{http_port}}.baidu.com