ansible变量优先级从低到高，命令行优先级最低，额外值得又相继最高

• command line values (eg “-u user”)
• role defaults [1]
• inventory file or script group vars [2]
• inventory group_vars/all [3]
• playbook group_vars/all [3]
• inventory group_vars/* [3]
• playbook group_vars/* [3]
• inventory file or script host vars [2]
• inventory host_vars/* [3]
• playbook host_vars/* [3]
• host facts / cached set_facts [4]
• play vars
• play vars_prompt
• play vars_files
• role vars (defined in role/vars/main.yml)
• block vars (only for tasks in block)
• task vars (only for the task)
• include_vars
• set_facts / registered vars
• role (and include_role) params
• include params
• extra vars (always win precedence)

范围变量

您可以根据希望该值具有的范围来决定在何处设置变量。Ansible有三个主要范围：

• 全局：这由配置，环境变量和命令行设置
• 播放：每个播放和包含的结构，vars条目(vars; vars_files; vars_prompt)，角色默认值和vars。
• 主机：与主机直接关联的变量，如库存，include_vars，事实或已注册的任务输出

ansible中变量地方太多了，是学习得重点，如果把变量放在最好的位置。