仅影响其中一台主机的错误 运行 剧本

Question

我最近开始越来越多地使用 Ansible，尤其是 AWX，来处理简单的重复性任务。下面是一个通过 Bash 脚本下载、安装和配置日志记录的剧本。该脚本适用于两个主机：Ubuntu 20.04 和 CentOS 7.6，对于后者，需要对 SELinux 进行一些更改。

问题是，为什么我只在 Ubuntu 而不是 CentOS 上收到错误？

这是剧本：

# Download an run Nagios Log Server configuration script
---
- name: nagios-log configure
  hosts: all
  remote_user: root
  tasks:
  
  - name: Distribution
    debug: msg="{{ ansible_distribution }}"

  - name: Download setup-linux.sh
    get_url: 
      url: http://10.10.10.10/nagioslogserver/scripts/setup-linux.sh
      validate_certs: no
      dest: /tmp/setup-linux.sh
      
  - name: Change script permission
    file: dest=/tmp/setup-linux.sh mode=a+x
      
  - name: Run setup-linux.sh
    shell: /tmp/setup-linux.sh -s 10.10.10.10 -p 5544
    register: ps
    failed_when: "ps.rc not in [ 0, 1 ]"
    
  - name: Install policycoreutils if needed
    yum: 
      name: 
        - policycoreutils
        - policycoreutils-python
      state: latest
    when: ansible_distribution == 'CentOS'
        
  - name: Check if policy file exists
    stat:
      path: /etc/selinux/targeted/active/ports.local
    register: result
    when: ansible_distribution == 'CentOS'

  - name: Check whether line exists
    find:
      paths: /etc/selinux/targeted/active/ports.local 
      contains: '5544'
    register: found
    when: result.stat.exists == True
    
  - name: Add SELinux policy exception if missing
    command: semanage port -a -t syslogd_port_t -p udp 5544
    when: found.matched > 0
    
  - name: Restart rsyslog
    systemd:
      name: rsyslog
      state: restarted
      enabled: yes

这是 运行 AWX 上的剧本时的错误输出：

TASK [Check whether line exists] ***********************************************
fatal: [Ubuntu.domain.corp]: FAILED! => {"msg": "The conditional check 'result.stat.exists == True' failed. The error was: error while evaluating conditional (result.stat.exists == True): 'dict object' has no attribute 'stat'\n\nThe error appears to be in '/tmp/awx_154_1811rny6/project/nagios-log.yml': line 39, column 5, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n\n  - name: Check whether line exists\n    ^ here\n"}
ok: [Centos.domain.corp]

由于我无法理解的原因，CentOS 服务器很好，但是 Ubuntu 出现了一个我不明白的奇怪错误。我尝试了其他方法来实现与 when 命令相同的逻辑。

Answer 1

你得到这个错误，因为你在

中注册了变量result

  - name: Check if policy file exists
    stat:
      path: /etc/selinux/targeted/active/ports.local
    register: result
    when: ansible_distribution == 'CentOS'

但是由于 when: ansible_distribution == 'CentOS' 这不会 运行 在 Ubuntu 上，因此当 运行 在 运行 上运行剧本时变量 result 不存在=29=].

要解决此问题（以及 运行 仅在 CentOS 上使用 result 的任务），您可以将其更改为：

  - name: Check whether line exists
    find:
      paths: /etc/selinux/targeted/active/ports.local 
      contains: '5544'
    register: found
    when:
    - ansible_distribution == 'CentOS'
    - result.stat.exists == True

  - name: Add SELinux policy exception if missing
    command: semanage port -a -t syslogd_port_t -p udp 5544
    when:
    - ansible_distribution == 'CentOS'
    - found.matched > 0

或者你可以像这样将所有 CentOS 特定任务放在 block 中：

  - name: CentOS specific tasks
    block:
    - name: Install policycoreutils if needed
      yum: 
        name: 
          - policycoreutils
          - policycoreutils-python
        state: latest
    - name: Check if policy file exists
      stat:
        path: /etc/selinux/targeted/active/ports.local
      register: result
    - name: Check whether line exists
      find:
        paths: /etc/selinux/targeted/active/ports.local 
        contains: '5544'
      register: found
      when: result.stat.exists == True      
    - name: Add SELinux policy exception if missing
      command: semanage port -a -t syslogd_port_t -p udp 5544
      when: found.matched > 0
    when: ansible_distribution == 'CentOS'

或者您可以将它们放在自己的文件中 include that file。实际上有很多方法可以做到这一点。