Ansible Roles 一键完成LNMP

Ansible Roles

一、Ansible Roles基本概述

1.Ansible Roles介绍

roles不管是Ansible还是saltstack，我在写一键部署的时候，都不可能把所有的步骤全部写入到一个'剧本'文件当中，我们肯定需要把不同的工作模块，拆分开来，解耦，那么说到解耦，我们就需要用到roles官方推荐，因为roles的目录结构层次更加清晰。

例如：我们之前推荐大家写一个lnmp.yml里面写所有基础优化的项目，其实把所有东西摞进去也是很鸡肋的，不如我们把这些功能全部拆分开，谁需要使用，就调用即可。

建议：每个roles最好只使用一个tasks这样方便我们去调用，能够很好的做到解耦。（SOA）

# 运维复杂的场景：建议使用 roles，代码复用度高

2.目录结构

production                # inventory file for production servers
staging                   # inventory file for staging environment

group_vars/
   group1.yml             # here we assign variables to particular groups
   group2.yml
host_vars/
   hostname1.yml          # here we assign variables to particular systems
   hostname2.yml

library/                  # if any custom modules, put them here (optional)
module_utils/             # if any custom module_utils to support modules, put them here (optional)
filter_plugins/           # if any custom filter plugins, put them here (optional)

site.yml                  # master playbook
webservers.yml            # playbook for webserver tier
dbservers.yml             # playbook for dbserver tier

roles/
   nginx/                 # this hierarchy represents a "role"
        tasks/            #
            main.yml      #  <-- tasks file can include smaller files if warranted
        handlers/         #
            main.yml      #  <-- handlers file
        templates/        #  <-- files for use with the template resource
            ntp.conf.j2   #  <------- templates end in .j2
        files/            #
            bar.txt       #  <-- files for use with the copy resource
            foo.sh        #  <-- script files for use with the script resource
        vars/             #
            main.yml      #  <-- variables associated with this role
        defaults/         #
            main.yml      #  <-- default lower priority variables for this role
        meta/             #
            main.yml      #  <-- role dependencies
        library/          # roles can also include custom modules
        module_utils/     # roles can also include custom module_utils
        lookup_plugins/   # or other types of plugins, like lookup in this case

    webtier/              # same kind of structure as "common" was above, done for the webtier role
    monitoring/           # ""
    fooapp/               # ""

2.创建roles目录

1.手动创建 (不推荐)

[root@m01 ~]# mkdir /project
[root@m01 ~]# cd /project/
[root@m01 project]# mkdir roles
[root@m01 project]# touch site.yml
[root@m01 project]# ll
total 0
drwxr-xr-x 2 root root 6 May  9 16:47 roles
-rw-r--r-- 1 root root 0 May  9 16:47 site.yml
[root@m01 roles]# mkdir {mariadb,php,nfs-client,nfs-server,nginx}
[root@m01 roles]# mkdir nginx/{tasks,files,templates,vars,handlers,meta} -p
[root@m01 roles]# tree nginx
nginx
├── files
├── handlers
├── meta
├── tasks
├── templates
└── vars

6 directories, 0 files


# 注释
nginx/                #项目名称
├── defaults        #低优先级变量
├── files           #存放文件
├── handlers        #触发器文件
├── meta            #依赖关系文件
├── tasks           #工作任务文件
├── templates       #jinja2模板文件
├── tests           #测试文件
└── vars            #变量文件