changed_when & failed_when

failed_when:

定义条件, 当条件满足时, 才判断任务失败, 而不是系统自动判断的rc

# this will never report 'failed' status

- shell: nmap -sS www.bbc.co.uk

register: nmap_result

failed_when: "root privileges" in nmap_result.stdout

changed_when:

定义条件, 当条件满足时, 才判断任务成功(更改)

# this will never report 'changed' status

- shell: ls

changed_when: False