使用来自另一个任务的变量的 Ansible when 语句

Question

有人可以帮我吗？我想在主机 "cfme_tester-0" 上创建一个文件夹。为此，我从 "undercloud-0" 主机检查变量 "osp_version"，并根据结果在 "cfme_tester-0" 主机上创建一个文件夹。

这是我的剧本：

- name: take openstack version
  hosts: undercloud-0
  become: true
  become_user: stack
  tasks:
    - name: creating flavor
      shell: |
        source /home/stack/stackrc
        cat /etc/rhosp-release | egrep -o '[0-9]+' | head -1
      register: osp_version
      ignore_errors: True
    - debug: msg="{{ osp_version.stdout }}"


- name: set up CFME tester
  hosts: cfme_tester-0
  become: yes
  become_user: root
  tasks:
    - name: Run prepare script for OSP10
      debug:
        shell: |
          cd /tmp/cfme/ && mkdir osp10
      when: "'10' in osp_version.stdout"

    - name: Run prepare script for OSP13
      debug:
        shell: |
          cd /tmp/cfme/ && mkdir osp13
      when: "'13' in osp_version.stdout"

但是出现错误：

TASK [debug] ******************************************************************************************************************************************************************************************************
ok: [undercloud-0] => {
    "msg": "10"
}

PLAY [set up CFME tester] *****************************************************************************************************************************************************************************************

TASK [Gathering Facts] ********************************************************************************************************************************************************************************************
ok: [cfme_tester-0]

TASK [Run prepare script for OSP10] *******************************************************************************************************************************************************************************
fatal: [cfme_tester-0]: FAILED! => {"msg": "The conditional check ''10' in osp_version.stdout' failed. The error was: error while evaluating conditional ('10' in osp_version.stdout): 'osp_version' is undefined\n\nThe error appears to have been in '/root/infrared/rhos-qe-core-installer/playbooks/my_setup.yaml': line 20, column 7, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n  tasks:\n    - name: Run prepare script for OSP10\n      ^ here\n"}
    to retry, use: --limit @/root/infrared/rhos-qe-core-installer/playbooks/my_setup.retry

PLAY RECAP ********************************************************************************************************************************************************************************************************
cfme_tester-0              : ok=1    changed=0    unreachable=0    failed=1   
undercloud-0               : ok=3    changed=1    unreachable=0    failed=0

Answer 1

变量是每个主机的（因为否则，当您运行多个主机上的任务和 register 变量时会发生什么？）。在您的第一个任务中，您正在为主机 undercloud-0.

设置 osp_version 变量

如果你想在你的第二个游戏中使用这个变量，即运行ning on cfme_tester-0，那么你应该阅读 Ansible 文档的 Magic Variables, and How To Access Information About Other Hosts 部分。您需要通过 hostvars 字典引用该变量，因此您的第二个剧本将如下所示：

- name: set up CFME tester
  hosts: cfme_tester-0
  become: yes
  become_user: root
  tasks:
    - name: Run prepare script for OSP10
      shell: |
        cd /tmp/cfme/ && mkdir osp10
      when: "'10' in hostvars['undercloud-0'].osp_version.stdout"

    - name: Run prepare script for OSP13
      shell: |
        cd /tmp/cfme/ && mkdir osp13
      when: "'13' in hostvars['undercloud-0'].osp_version.stdout"

...但请注意，如果您只是创建目录，最好只使用 file 模块：

    - name: Run prepare script for OSP10
      file:
        path: /tmp/cfme/osp10
        state: directory
      when: "'10' in hostvars['undercloud-0'].osp_version.stdout"

使用来自另一个任务的变量的 Ansible when 语句

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