ansible - Ansible 处理程序和条件

Question

我试图找到一个逻辑来检查服务是否正在运行，如果没有运行，则启动它。下面是我写的逻辑，但由于某种原因，通知没有调用处理程序？

    ---
    - name: Executing the play to start the service
      hosts: nodes
      become: yes
      gather_facts: False
    
      tasks:
    
      - name: Executing the Shell task to check the status of the wso2 instance
        shell: myMsg=$(sudo service wso2esb status| grep Active | awk '{print $3}');if [[ $myMsg == "(dead)" ]]; then echo "Not Running";else echo "Running";fi
        ignore_errors: yes
        register: result
        notify: handl
        when: result.stdout == "Not Running"  (I even tried 'changed_when', but the same error)
    
      handlers:
      - name: handl
        service: name=wso2esb state=started

$ ansible-playbook -i inventories/hosts.sit start.yml -b -k
SSH password:

PLAY [Executing the play to start the wso2 service] ***********************************************

    TASK [Executing the Shell task to check the status of the instance] *******************************
    fatal: [mpstest01]: FAILED! => {"msg": "The conditional check 'result.stdout == \"Not Running\"' failed. The error was: error while evaluating conditional (result.stdout == \"Not Running\"): **'result' is undefined**\n\nThe error appears to have been in '/home/ansible1/start.yml': line 9, 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: Executing the Shell task to check the status of the instance\n    ^ here\n"}
    ...ignoring
    
    PLAY RECAP ****************************************************************************************
    mpstest01                  : ok=1    changed=0    unreachable=0    failed=0

标签： ansible

Answer 1

这一切似乎都是不必要的。您不需要“检查服务是否正在运行，如果未运行，则启动它”；这正是服务模块所做的。只需将service模块放入任务中，不要打扰处理程序：

  - name: start service if it isn't already running
    service: name=wso2esb state=started

虽然我更喜欢 YAML 语法而不是 key=value 语法：

  - name: start service if it isn't already running
    service:
      name: wso2esb
      state: started

在任何情况下，service模块都会检查服务是否正在运行，如果没有，它将启动它。