ansible 变量的讲解

Global scope

可以通过选项 -e传递给 ansible 或者 ansible-playbook 命令

# 传递package变量
[aaa@controller webapp 18:29:22]$ ansible node1 -m debug -a "msg={{ package }}" -e "package=nginx"
node1 | SUCCESS => {
    "msg": "nginx"
}
[aaa@controller webapp 18:29:57]$

Play scope

• vars 声明

# vars.yaml
---
- name: the use of vars
  hosts: node1
  vars:
    user: abc
    home: /home/abc
  tasks:
    - name: add user {{ user }}
      user:
        name: "{{ user }}"
        home: "{{ home }}"
        state: present

    - name: debug user
      debug:
        msg: |
          username is {{ user }}
          home is {{ home }}

• vars_files

# ./vars/user1.yaml
user: qwe
home: /home/{{ user }}

# vars_files.yaml
---
- name: the use of vars
  hosts: node1
  vars_files:
    - vars/user1.yaml
  tasks:
    - name: add user {{ user }}
      user:
        name: "{{ user }}"
        home: "{{ home }}"
        state: present

    - name: debug user
      debug:
        msg: |
          username is {{ user }}
          home is {{ home }}

Host scope

# inventory
[controllers]
controller

[webs]
node1 user=qwe
node2 user=kkk

[dbs]
node3
node4

[nodes]
node[1:4]

目录分层结构定义

• group_vars:定义主机组变量。目录中文件名可以直接使用主机组名或者主机组名.yaml
• host_vars:定义主机变量。目录中文件名可以直接使用主机名或者主机名.yaml

mkdir host_vars group_vars
touch host_vars/node1.yaml
touch group_vars/webs.yaml
vim host_vars/node1.yaml
vim group_vars/webs.yaml

# webs.yaml
user: Kkkkk
# node1.yaml
user: aaa

ansible nodes -m debug -a 'msg="hello {{ user }}"'

主机连接特殊变量

• ansible_host:要连接的主机的名称，默认值就算主机清单名称
• ansible_user:ssh 用户名
• ansible_ssh_pass:要使用的 ssh 密码，切勿以纯文本形式存储此变量。
• ansible_ssh_private_key_file:ssh 使用的私钥文件。
• ansible_become:是否要进行提权
• ansible_become_method:设置提权提升方式
• ansible_become_user:提权后升级称为的用户
• ansible_become_pass:权限提升的密码

数组变量

# vars_array.yaml
users:
 person_one:
  user_name: laoba
  home_dir: /home/laoba
 person_two:
  user_name: laoliu
  home_dir: /home/laoliu

# use_array.yaml
---
- name: use vars array
  hosts: node1
  vars_files:
    - ./vars_array.yaml
  tasks:
    - name: debug the info
      debug:
        var: users

    - name: "add user {{ users.person_one.user_name }}"
      user:
        name: "{{ users.person_one.user_name }}"
        home: "{{ users.person_one.home_dir }}"

ansible 各种模块的使用

• file

# module_file_use.yaml
---
- name: to control file and directory
  gather_facts: no
  hosts: node1
  tasks:
    - name: create a directory
      file:
        path: /web_dir
        owner: aaa
        group: wheel
        mode: 0755
        state: directory

    - name: touch a file
      file:
        path: /web_dir/file
        state: touch
        mode: 0640
        owner: aaa
        group: wheel

    - name: delete a file
      file:
        path: /web_dir/file
        state: absent

• lineinfile

# 确保文件中存在特定行
---
- hosts: node1
 gather_facts: no
 tasks:
   - name: add line
     lineinfile:
       path: /tmp/testfile
       line: 'Add this line to file'
       state: present
# 特定位置插入
# insertbefore，最后一个匹配到前插入
---
- hosts: node1
 gather_facts: no
 tasks:
   - name: add line
     lineinfile:
       path: /etc/httpd/conf/httpd.conf
       line: 'Listen 82'
       insertbefore: 'Listen 80'
       state: present
# insertafter，最后一个匹配到后插入
---
- hosts: node1
 gather_facts: no
 tasks:
   - name: add line
     lineinfile:
       path: /etc/httpd/conf/httpd.conf
       line: 'Listen 82'
       insertafter: 'Listen 80'
       state: present
# 替换文本行
---
- hosts: node1
 gather_facts: no
 tasks:
   - name: replace line
     lineinfile:
       path: /tmp/testfile
       regexp: 'Add'
       line: 'replace'
       state: present
# 替换多行文本
---
- hosts: node1
 gather_facts: no
 tasks:
 - name: add line
   lineinfile:
     path: /tmp/testfile
     line: |
       line 1
       line 2
     regexp: 'replace'
     state: present

• replace

该模块使用正则表达式匹配内容，将匹配的内容替换成指定的内容

---
- hosts: node1
 gather_facts: no
 tasks:
   - name: replace multi line
     replace:
       path: /tmp/testfile
       regexp: '^Hello World.*'
       replace: 'Hello Laoma'

• copy

• 将控制节点上的文件拷贝到受管理节点，类似于 linux 中的 scp 命令

---
- hosts: node1
 gather_facts: no
 tasks:
   - name: copy /tmp/testfile to remote node
     copy:
       src: /tmp/testfile
       dest: /tmp

• 写入字符串到文件

---
- hosts: node1
  gather_facts: no
  tasks:
    - name: write string into /tmp/testfile
      copy:
        content: "hello world\n"
        dest: /tmp/testfile