如何使用Ansible动态注册变量？

Question

我想定义一个Ansible角色并注册动态变量:

---
- name: Check for {{ package }}
  stat: path=/opt/packages/{{ package }}
  register: "{{ package | regex_replace('-', '_') }}"
- name: Install {{ package }} {{ package_version }}
  command: "custom-package-installer {{ package }} {{ package_version }}"
  when: "not {{ package | regex_replace('-', '_') }}.stat.exists"

用法如下:

- include: install_package.yml package=foo package_version=1.2.3

但是,Ansible不承认条件:

TASK: [example | Install foo 1.2.3] *********************************** 
fatal: [my-server] => error while evaluating conditional: not foo.stat.exists

FATAL: all hosts have already failed -- aborting

如何动态定义变量,扩展{{ }}？

Answer 1

无法注册动态变量.{{ var }}注册占位符是没有办法的.然而,有一种更清洁的方式来执行我认为你想要实现的目标:Ansible:这是事实.

简短的摘要:

您可以编写一个打印JSON的简单脚本,如:

#!/bin/python #or /bin/bash or any other executable
....

print """{ "ansible_facts": {
              "available_packages": ["a", "b", "c"]
               }
          }"""

并将其放入计算机上的本地事实文件夹中(作为带有.fact结尾的可执行脚本):

Your second task would then look like:

- name: Install {{ package }} {{ package_version }}
  command: "custom-package-installer {{ package }} {{ package_version }}"
  when: "not package in ansible_facts['available_packages']"

Ansible关于事实的文档.