bash 在ansible中检查shell命令的输出
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Checking output of a shell command in ansible
提问by Omri
I'm trying to write an Ansible script that runs a shell pipeline, and determines whether to terminate the playbook's execution based on that pipeline's output.
我正在尝试编写一个运行 shell 管道的 Ansible 脚本，并根据该管道的输出确定是否终止剧本的执行。
Here is the problematic code:
这是有问题的代码：
- name: Check if the number of HITACHI devices is equal to 1
shell: lsscsi | grep HITACHI | awk '{print }' | wc -l
register: numOfDevices
when: numOfDevices|int == 1
Here is the error:
这是错误：
{
"failed":true,
"msg":"The conditional check 'numOfDevices|int == 1' failed.
The error was: error while evaluating conditional (numOfDevices|int == 1): 'numOfDevices' is undefined\n\nThe error appears to have been in '/etc/ansible/config/test.yml': line 14, 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: Check if the number of HITACHI devices is equal to 1\n ^ here\n"
}
Can someone tells me what could be the issue?
有人可以告诉我可能是什么问题吗？
回答by Charles Duffy
Consider doing the comparison in your shell command:
考虑在你的 shell 命令中进行比较：
- name: Check if the number of HITACHI devices is equal to 1
shell: test "$(lsscsi | awk '/HITACHI/ { count++ } END { print count }')" -eq 1
You don't need to use registerat all here, since the default failedWhenis when the exit status of a command is nonzero.
您根本不需要register在这里使用，因为默认值failedWhen是命令的退出状态为非零时。
If you didwant to use register, however:
但是，如果您确实想使用register：
- name: Check if the number of HITACHI devices is equal to 1
shell: lsscsi | awk '/HITACHI/ { count++ } END { print count }'
register: countHitachiDevices
failed_when: int(countHitachiDevices.stdout) != 1
Note the use of failed_wheninstead of when: A whenclause determines if a command is going to be run at all, whereas a failed_whenclause determines whether that command is determined to have failed.
请注意使用failed_when替代when：when子句确定是否要运行命令，而failed_when子句确定该命令是否已确定为失败。
