doc: update ansible.md (#31)

* update ansible inventory静态分组用法

* Update ansible.md

docs/ansible.md

@@ -39,6 +39,30 @@ mail.example.com
 [webservers]
 foo.example.com
 bar.example.com
+
+Inventory主机组使用多个IP和域名
+ [web]
+172.18.12.5[1:4]
+[webservers]
+www[01:50].example.com
+
+Inventory主机组使用子主机组
+[usa:children]
+southeast
+northeast
+southwest
+northwest
+
+给多台主机设置变量 : group variables
+如果组中的所有主机共享一个变量值，则可以一次将该变量应用于整个组
+[atlanta]
+host1
+host2
+
+[atlanta:vars]
+ntp_server=ntp.atlanta.example.com
+proxy=proxy.atlanta.example.com
+
 ```
 
 ## 命令行(ad-hoc)
@@ -364,4 +388,4 @@ $ ansible-pull -U <repository> [options]
 ---
 [Getting started with Ansible](https://docs.ansible.com/ansible/latest/getting_started/index.html)  
 [Introduction to ad hoc commands](https://docs.ansible.com/ansible/latest/user_guide/intro_adhoc.html)
-[Ansible cheatsheet](https://github.com/luckylittle/ansible-cheatsheet/blob/master/ansible-cheatsheet.txt)
+[Ansible cheatsheet](https://github.com/luckylittle/ansible-cheatsheet/blob/master/ansible-cheatsheet.txt)