今天碰到一個(gè)需求，當(dāng)使用ansible-playbook在執(zhí)行一個(gè)腳本后，根據(jù)腳本返回的內(nèi)容判斷是否繼續(xù)往下執(zhí)行還是中斷執(zhí)行，查詢官網(wǎng)發(fā)現(xiàn)使用register寄存器可以實(shí)現(xiàn)記錄腳本輸出，使用when+fail模塊來(lái)判斷是否往下繼續(xù)執(zhí)行或者中斷，以下是一個(gè)簡(jiǎn)單例子：

ansible服務(wù)在172.16.133.128上，先執(zhí)行一個(gè)腳本，腳本返回success時(shí)在172.16.133.129上創(chuàng)建一個(gè)目錄/tmp/test，如果返回failed則中斷執(zhí)行

先在172.16.133.129上配置一個(gè)簡(jiǎn)單腳本/tmp/test.sh

#!/bin/bash
echo "failed"

配置yml文件test.yml，先配置執(zhí)行腳本部分

---

• hosts: 172.16.133.129
  remote_user: root
  tasks:
  • command: /tmp/test.sh
    register: result
    這里使用了register寄存器，具體寄存了什么內(nèi)容，可以使用-v參數(shù)來(lái)查看輸出

使用ansible-playbook運(yùn)行

[root@localhost ansible]# ansible-playbook -v test.yml
PLAY [172.16.133.129] *
GATHERING FACTS ***
ok: [172.16.133.129]
TASK: [command /tmp/test.sh] **
changed: [172.16.133.129] => {"changed": true, "cmd": ["/tmp/test.sh"], "delta": "0:00:00.002602", "end": "2016-04-11 17:00:57.227517", "rc": 0, "start": "2016-04-11 17:00:57.224915", "stderr": "", "stdout": "failed", "warnings": []}
PLAY RECAP ****
172.16.133.129 : ok=2 changed=1 unreachable=0 failed=0
register保存的信息就時(shí)“=>”后面的字典信息，信息保存在result變量中

可以看到"stdout"就是腳本的標(biāo)準(zhǔn)輸出信息，這時(shí)可以使用"when"來(lái)判斷是否執(zhí)行或者跳過(guò)

修改test.yml

---

• hosts: 172.16.133.129
  remote_user: root
  tasks:

  • command: /tmp/test.sh
    register: result

  • file: path=/tmp/test state=directory
    when: result.stdout == ‘failed‘
    當(dāng)腳本輸出為‘failed‘時(shí)就會(huì)執(zhí)行創(chuàng)建目錄操作，輸出不為‘failed‘，則跳過(guò)執(zhí)行

執(zhí)行yml后輸出如下：

[root@localhost ansible]# ansible-playbook -v test.yml

PLAY [172.16.133.129] *****

GATHERING FACTS ***
ok: [172.16.133.129]

TASK: [command /tmp/test.sh] **
changed: [172.16.133.129] => {"changed": true, "cmd": ["/tmp/test.sh"], "delta": "0:00:00.002618", "end": "2016-04-11 17:11:07.957097", "rc": 0, "start": "2016-04-11 17:11:07.954479", "stderr": "", "stdout": "failed", "warnings": []}

TASK: [file path=/tmp/test state=directory] ***
changed: [172.16.133.129] => {"changed": true, "gid": 0, "group": "root", "mode": "0755", "owner": "root", "path": "/tmp/test", "size": 4096, "state": "directory", "uid": 0}

PLAY RECAP ****
172.16.133.129 : ok=3 changed=2 unreachable=0 failed=0

修改test.sh，輸出‘success‘，然后執(zhí)行test.yml

[root@localhost ansible]# ansible-playbook -v test.yml

PLAY [172.16.133.129] *****

GATHERING FACTS ***
ok: [172.16.133.129]

TASK: [command /tmp/test.sh] **
changed: [172.16.133.129] => {"changed": true, "cmd": ["/tmp/test.sh"], "delta": "0:00:00.002611", "end": "2016-04-11 17:14:08.456293", "rc": 0, "start": "2016-04-11 17:14:08.453682", "stderr": "", "stdout": "success", "warnings": []}

TASK: [file path=/tmp/test state=directory] ***
skipping: [172.16.133.129]

PLAY RECAP ****
172.16.133.129 : ok=2 changed=1 unreachable=0 failed=0
可以看到當(dāng)stdout為success時(shí)，創(chuàng)建目錄的操作直接跳過(guò)了

現(xiàn)在回到最終要達(dá)到的目的，當(dāng)腳本輸出為‘failed‘時(shí)，我們要中斷ansible-playbook執(zhí)行，而不是跳過(guò)，這時(shí)需要配合fail模塊來(lái)實(shí)現(xiàn)，并且可以拋出自定義信息

修改test.sh文件,輸出‘failed‘

修改test.yml

---

• hosts: 172.16.133.129
  remote_user: root
  tasks:

  • command: /tmp/test.sh
    register: result

  • name: if stdout ‘failed‘ ,Interrupt execution
    fail: msg="check failed"
    when: result.stdout == ‘failed‘

  • file: path=/tmp/test state=directory
    如果腳本執(zhí)行返回‘failed‘，中斷執(zhí)行，并拋出信息"check failed"

[root@localhost ansible]# ansible-playbook -v test.yml

PLAY [172.16.133.129] *****

GATHERING FACTS ***
ok: [172.16.133.129]

TASK: [command /tmp/test.sh] **
changed: [172.16.133.129] => {"changed": true, "cmd": ["/tmp/test.sh"], "delta": "0:00:00.002632", "end": "2016-04-11 17:27:47.248996", "rc": 0, "start": "2016-04-11 17:27:47.246364", "stderr": "", "stdout": "failed", "warnings": []}

TASK: [check ,Interrupt execution] ****
failed: [172.16.133.129] => {"failed": true}
msg: check failed

FATAL: all hosts have already failed -- aborting

PLAY RECAP ****
to retry, use: --limit @/root/test.retry

172.16.133.129 : ok=2 changed=1 unreachable=0 failed=1
playbook運(yùn)行到第二個(gè)task時(shí)就會(huì)報(bào)錯(cuò)并拋出msg

ansible官網(wǎng)文檔：http://docs.ansible.com/ansible/playbooks_conditionals.html#register-variables

注：寄存器中的數(shù)據(jù)都可以拿來(lái)使用，如"rc","stderr"等，當(dāng)然也有很多種方法，文中的‘failed‘是嚴(yán)格匹配，也可以使用模糊查找，如result.stdout.find(‘failed‘) != -1也可以達(dá)到相同的效果

本文出自 “漂泊的魚” 博客，請(qǐng)務(wù)必保留此出處http://faded.blog.51cto.com/6375932/1762688

轉(zhuǎn)載于:https://blog.51cto.com/lookingdream/2054763

總結(jié)

以上是生活随笔為你收集整理的ansible-playbook如何判断并中断执行的全部?jī)?nèi)容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網(wǎng)站內(nèi)容還不錯(cuò)，歡迎將生活随笔推薦給好友。