如果可以使用ansible，我如何实现安装yum包？

Question

我想在ansible中实现这个逻辑：如果可用，安装一个命名的yum包，如果启用的repos中不存在包，则不会失败，只有在安装失败时才会失败。

Answer 1

首先进行搜索，只有在返回任何结果时才安装：

- hosts: host
  tasks:
    - name: Search for package
      yum:
        list: <package_name>
      register: package_list

    - name: Install package
      yum:
        name: <package_name>
        state: present
      become: yes
      when: 'package_list.results | length != 0'

将<package_name>替换为您感兴趣的包。

以下是failed_when的替代方案，但它非常hacky，因为它依赖于yum返回的消息来匹配：

- hosts: host
  tasks:
    - name: Install package
      yum:
        name: <package_name>
        state: present
      register: result
      become: yes
      failed_when: '(result.msg | regex_replace("No package matching .* found available, installed or updated","")) != ""'