Include语句
Include语句的功能,基本的代码重用机制。主要重用tasks。同时Include可将tasks分割成多个文件,避免Playbook过于臃肿,使用户更关注于整体的架构,而不是实现的细节上。
普通用法
像其它语言的Include语句一样,直接Include:
---
# possibly saved as tasks/firewall_httpd_default.yml
- name: insert firewalld rule for httpd
firewalld: port=80/tcp permanent=true state=enabled immediate=yes
main.yml文件中调用include的方法:
tasks:
- include: tasks/firewall_httpd_default.yml
高级用法-使用参数
include文件中还可以定义参数
被include的文件tasks/firewall_httpd_default.yml中,使用{{ port }}
定义了一个名字为port的参数。
---
- name: insert firewalld rule for httpd
firewalld: port={{ port }}/tcp permanent=true state=enabled immediate=yes
传参数的各种方法
在执行的playbook传参数,可以加在行尾,使用空格分隔:
tasks:
- include: tasks/firewall.yml port=80
- include: tasks/firewall.yml port=3260
- include: tasks/firewall.yml port=423
还可以使用yml的字典传参数:
tasks:
- include: wordpress.yml
vars:
wp_user: timmy
ssh_keys:
- keys/one.txt
- keys/two.txt
还可以把一条task简写成成一个类JSON的形式传参数:
tasks:
- { include: wordpress.yml, wp_user: timmy, ssh_keys: [ 'keys/one.txt', 'keys/two.txt' ] }
当然在playbook中已经定义了的参数,就不需要再显示传入值了,可以直接写成下面的:
---
- hosts: lb
vars:
port: 3206
remote_user: root
tasks:
- include: tasks/firewall.yml
include语句相关的那些坑
在handlers里面加include
handlers中加入include语句的语法如下:
handlers:
- include: handlers/handlers.yml
然而为什么有一处文档里面写可以调用。文档下面两个地方提到include里面的handlers,但是两处是矛盾的:
- hander的文档写不能调用
http://docs.ansible.com/ansible/playbooks_intro.html - include的文档写能调用
http://docs.ansible.com/ansible/playbooks_roles.html#task-include-files-and-encouraging-reuse
通过下面的例子实测后,基于ansible1.9是不能调用include里面的handler的,不过基于ansible2.0+是可以调用include里面的handler的。所以在使用的时候注意你安装的ansible版本。
- hosts: lb
user: root
gather_facts: no
vars:
random_number: "{{ 10000 | random }}"
tasks:
- name: Copy the /etc/hosts to /tmp/hosts.{{ random_number }}
copy: src=/etc/hosts dest=/tmp/hosts.{{ random_number }}
notify:
- restart apache
- restart apache in handlers
handlers:
- include: handlers/handlers.yml
- name: restart apache
debug: msg="This is the handler restart apache"
Ansible允许的全局(或者叫plays)加include
然而这种使用方式并不推荐,首先它不支持嵌入include,而且很多playbook的参数也不可以使用。
- name: this is a play at the top level of a file
hosts: all
remote_user: root
tasks:
- name: say hi
tags: foo
shell: echo "hi..."
# 全局include,或者叫playbook include
- include: load_balancers.yml
- include: webservers.yml
- include: dbservers.yml
为了使include功能更强大,在每个新出的ansible都会添加新的一些功能,例如在2.0中添加了include动态名字的yml,然而这样的用法有很多的限制,不够成熟,可能在更新的ansible又去掉了,学习和维护成本很高。所以需要使用更灵活的重用机制时,建议用下一节介绍的role。