Anisble中的任务执行控制

一、循环

1、简单循环

使用loop赋值列表的格式：

loop:  ##赋值列表
- value1
- value2
- ...
{{item}}  ##迭代变量名称

2、循环散列或字典列表

可以赋予不同的服务不同的状态

- name: create file
 hosts: 172.25.0.254
 tasks:
 - name: file module
 service:
 name: "{{ item.name}}"
 state: "{{ item.state }}"
 loop:
 - name: httpd
 state: started
 - name: vsftpd
 state: stopped

二、条件判定

1、when条件语句

此条件代表两者都满足时

when:
- 条件1
- 条件2

此条件代表两者满足一个即可

when:
- 条件1 
  or 
  条件2

2、条件判断


`=`	value `==` "字符串“，value `==` 数字
`<`	value `<` 数字
`>`	value `>` 数字
`<=`	value `<=` 数字
`>=`	value `>=` 数字
`!=`	value `!=` 数字

`is defined`	value is defined（变量存在）
`is not defined`	value is not defined（变量不存在）
`in`	value is in value（变量为）
`not in`	value is not in value（变量不为）
bool变量为`true`	value（value的值为true）
bool变量`false`	not value（value的值为false） value in value2（value的值在value2列表中）

上述的应用实例：

使用loop when 创建用户

vim user.yml

- name: create user
  hosts: all
  vars:
    userlist:
    - name: user1
      id: 6666
      comment: user1 comment
    - name: user2
      id: 7777
  tasks:
  - name: create user2
    user:
      name: "{{item.name}}"
      uid: "{{item.id}}"
      comment: "{{item.comment}}"
      state: present
    when:
      item.comment is defined
    loop:
      "{{userlist}}"
  - name: create user
    user:
      name: "{{item.name}}"
      uid: "{{item.id}}"
      state: present
    when:
      item.comment is not defined
    loop:
      "{{userlist}}"

ansible-playbook user.yml  -C

三、触发器

notify：触发器当遇到更改时触发handlers
handlers：触发器触发后执行的动作

示例：

使用触发器 j2 loop 安装httpd服务并运行虚拟主机

vim web.yml

webs:
- doc: /var/www/html
  index: "www.westos.org's page"

- name: bbs.westos.org
  doc: /var/www/virtual/westos.org/bbs/html
  index: "bbs.westos.org's page"

- name: login.westos.org
  doc: /var/www/virtual/westos.org/login/html
  index: "login.westos.org's page"

vim vhosts.conf.j2

{% for web in webs %}
{% if web.name is defined %}
<VirtualHost *:80>
  ServerName {{web.name}}
{% endif %}
{% if web.name is not defined %}
<VirtualHost _default_:80>
{% endif %}
  DocumentRoot {{web.doc}}
</VirtualHost>
{% endfor %}

vim httpd.yml

- name: create virtualhost
  hosts: all
  vars_files: ./web.yml
  tasks:
  - name: yum
    yum:
      name: httpd
      state: present

  - name: service
    service:
      name: httpd
      state: started
      enabled: yes

  - name: create doc
    lineinfile:
      path: "{{item.doc}}/index.html"
      line: "{{item.index}}"
      create: yes
    loop: "{{webs}}"

  - name: create vhosts.conf
    template:
      src: ./vhosts.conf.j2
      dest: /etc/httpd/conf.d/vhost.conf
    notify: restart httpd

  handlers:
  - name: restart httpd
    service:
      name: httpd
      state: restarted

触发器工作