当shell命令没有输出时，Ansible寄存器失败

我试图检查服务是否正在运行，然后将其输出注册到某个变量。如果服务未运行，则启动服务。下面是我的Ansible剧本片段

- hosts: localhost
  tasks:
  - name: check if service is running
    shell: pgrep node
    register: pgrep
  - name: stop running service
    shell: pkill node
    when: pgrep.stdout_lines != ''
    tags:
    - stop
  - name: start running service
    shell: pkill node
    when: pgrep.stdout_lines == ''
    tags:
    - start

现在，在上述情况下，如果进程未运行，

pgrep node

命令将退出状态代码返回为1，这将使“检查服务是否正在运行”任务失败，并中止进一步执行任务。通过设置

ignore\u errors，我知道：true

将忽略错误并继续执行，但Ansible运行失败。有什么方法可以让我们优雅地处理这个问题吗？

您可以在

pgrep

的返回代码为2或3时将条件设置为失败

根据

man pgrep

：

 The pgrep and pkill utilities return one of the following values upon exit:

 0       One or more processes were matched.
 1       No processes were matched.
 2       Invalid options were specified on the command line.
 3       An internal error occurred.

因此，Ansible任务应该如下所示：

- name: check if service is running
  shell: pgrep node
  register: pgrep
  failed_when: "pgrep.rc == 2 or pgrep.rc == 3"

当来自

pgrep

的返回代码为2或3时，您可以将条件设置为失败

根据

man pgrep

：

 The pgrep and pkill utilities return one of the following values upon exit:

 0       One or more processes were matched.
 1       No processes were matched.
 2       Invalid options were specified on the command line.
 3       An internal error occurred.

因此，Ansible任务应该如下所示：

- name: check if service is running
  shell: pgrep node
  register: pgrep
  failed_when: "pgrep.rc == 2 or pgrep.rc == 3"

---

添加答案供将来参考。如果存在多个进程，如何杀死它们。仅在rc==0时指示更改。除非rc==2或rc==3，否则不显示失败

- name: "Kill any processes"
  become: True
  vars:
    processes_to_kill: ["p1", "p2", "p3", "p4"]
  shell: "pkill -f {{ item }}"
  with_items: "{{ processes_to_kill }}"
  register: pkill
  failed_when: "pkill.rc == 2 or pkill.rc == 3"
  changed_when: "pkill.rc == 0"

---

添加答案供将来参考。如果存在多个进程，如何杀死它们。仅在rc==0时指示更改。除非rc==2或rc==3，否则不显示失败

- name: "Kill any processes"
  become: True
  vars:
    processes_to_kill: ["p1", "p2", "p3", "p4"]
  shell: "pkill -f {{ item }}"
  with_items: "{{ processes_to_kill }}"
  register: pkill
  failed_when: "pkill.rc == 2 or pkill.rc == 3"
  changed_when: "pkill.rc == 0"

---

“…将忽略错误并继续，但ansible运行失败。”我不明白这是什么意思。我的意思是，检查服务是否正在运行的特定任务仍然失败，尽管执行继续执行其他任务“…将忽略错误并继续，但ansible运行失败。”我不明白这意味着什么。我的意思是，检查服务是否正在运行的特定任务仍然失败，尽管执行继续执行进一步的任务