一、Ansible Roles 介绍

它允许管理员将他们复杂的PlayBook分解成一个个小的逻辑单元，以便于维护和管理。

二、Roles结构

1、Role是什么

先看一个示例

root@zsh-virtual-machine:~# tree nginx
nginx
├── files
│   └── alonzo.txt
├── handlers
│   └── main.yaml
├── tasks
│   └── main.yaml
├── templates
│   └── config.j2
└── vars
    └── main.yaml

5 directories, 5 files

从表面上看，它就是一个目录，目录的名字也就是role的名字，示例中role的名字就叫做nginx
在这个role名字的目录里，会发现好多子目录
使用时，每个目录必须包含一个main.yaml，这个文件应该包含如下目录名称对应的内容：

tasks 包含角色要执行的主要列表
handlers 包含处理程序，此角色甚至该角色之外的任何地方都可以使用这些处理程序
defaults 校色的默认变量
vars 角色的其他变量
files 包含可以通过角色部署的文件
templates 包含可以通过此角色部署的模板
meta 为此角色定义一些元数据
注意：这些目录用不到时可以删除

三、制作一个Role

将之前笔记中的一个完整的PlayBook分解成一个Role，那么应该怎么做呢？

最终优化的PlayBook

- name: install nginx or httpd
  hosts: all
  remote_user: root
  vars:
    username:
      - user1
      - user2
      - user3
  tasks:
    - name: create user
      user:
        name: "{{ item }}"
        home: /home/{{ item }}
      loop: "{{ username }}"
    - name: install nginx ubuntu
      apt:
        name: nginx
        state: present
        update_cache: yes
      when:
        - ansible_pkg_mgr == 'apt'
      notify: ubuntu
    - name: install httpd centos
      yum:
        name: httpd
        state: present
      when:
        - ansible_pkg_mgr == 'yum'
      notify: centos
    - name: copy file
      copy:
        src: /root/alonzo.txt
        dest: /root/alonzo.txt
    - name: update jinjia2 config
      template:
        src: config.j2
        dest: /root/cfg.conf
    - name: check nginx config
      shell: /usr/sbin/nginx -t
      register: nginx_check_config
      tags: restart_nginx
  handlers:
    - name: ubuntu
      service:
        name: nginx
        state: restarted
      when:
        - nginx_check_config.rc == 0
      tags: restart_nginx
    - name: centos
      service:
        name: httpd
        state: restarted

分解这个PlayBook，命名role的名字为nginx

nginx
├── files
│   └── alonzo.txt
├── handlers
│   └── main.yaml
├── tasks
│   └── main.yaml
├── templates
│   └── config.j2
└── vars
    └── main.yaml

files文件夹存放需要copy的文件

templates文件夹需要存放Jinja2文件

{# check system #}
{{ ansible_date_time.date }}
hostname:{{ ansible_hostname }}
os:{{ansible_os_family}}
ip:{{ ansible_default_ipv4.address }}
{% for m in ansible_mounts if m['mount'] != "/" %}
mount:{{ m['mount'] }} total size:{{ m['size_total'] }} free_size:{{ 'size_available' }}
{% endfor %}
memory_total:{{ ansible_memory_mb.real.total }} memory_free:{{ ansible_memory_mb.real.free }}
{% if ansible_processor_vcpus > 1 %}
system cpu core more than one core
{% endif %}

handlers文件夹中的main.yaml文件

- name: ubuntu
  service:
    name: nginx
    state: restarted
  when:
    - nginx_check_config.rc == 0
  tags: restart_nginx
- name: centos
  service:
    name: httpd
    state: restarted

vars文件夹中的main.yaml文件

username:
  - user1
  - user1
  - user1

tasks文件夹中的main.yaml文件

- name: create user
  user:
    name: "{{ item }}"
    home: /home/{{ item }}
  loop: "{{ username }}"
- name: install nginx ubuntu
  apt:
    name: nginx
    state: present
    update_cache: yes
  when:
    - ansible_pkg_mgr == 'apt'
  notify: ubuntu
- name: install httpd centos
  yum:
    name: httpd
    state: present
  when:
    - ansible_pkg_mgr == 'yum'
  notify: centos
- name: copy file
  copy:
    src: alonzo.txt
    dest: /root/alonzo.txt
- name: update jinjia2 config
  template:
    src: config.j2
    dest: /root/cfg.conf
- name: check nginx config
  shell: /usr/sbin/nginx -t
  register: nginx_check_config
  tags: restart_nginx

四、执行方式

1、经典方式

目录结构

root@zsh-virtual-machine:~/server# pwd
/root/server
root@zsh-virtual-machine:~/server# tree
.
├── hosts
├── nginx
│   ├── files
│   │   └── alonzo.txt
│   ├── handlers
│   │   └── main.yaml
│   ├── tasks
│   │   └── main.yaml
│   ├── templates
│   │   └── config.j2
│   └── vars
│       └── main.yaml
└── nginx_test.yaml

nginx_test.yaml文件内容

- name: a playbook used role
  hosts: all
  roles:
    - nginx

执行命令

root@zsh-virtual-machine:~/server# ansible-playbook -i hosts nginx_test.yaml

2、新方式