示例：
# Example that prints the loopback address and gateway for each host - debug: msg="System {{ inventory_hostname }} has uuid {{ ansible_product_uuid }}" - debug: msg="System {{ inventory_hostname }} has gateway {{ ansible_default_ipv4.gateway }}" when: ansible_default_ipv4.gateway is defined - shell: /usr/bin/uptime register: result - debug: var=result - name: Display all variables/facts known for a host debug: var=hostvars[inventory_hostname]
说明：
ansible-doc debug
debug是ansible版本的print语句 可以输出变量的内容或者随意的字符串 利于playbook执行阶段的调试
Options: (= is mandatory)(= 后面的参数是强制要有的)
- msg
输出定义好的meassage 如果没有message 默认输出Hello world!
- var
输出变量的内容 不可与msg选项共用
原文：http://www.cnblogs.com/metasequoia/p/5227700.html