ansible根据shell命令返回值，判断是否应该急继续往下执行

---
- hosts: host
  become: yes 
  tasks:
  - name: 判断用户是否存在
    shell: "grep  llldb  /etc/passwd"
    register: result
    failed_when: " 'llldb'  in result.stdout"
  - debug:
      var: result.stdout

参考文档：https://blog.csdn.net/qq_36417677/article/details/105342211