Ansible_处理失败的任务【转】

一、Ansible处理任务失败

1、管理play中任务错误

1️⃣：Ansible评估任务的返回代码，从而确定任务是成功还是失败

2️⃣：通常而言，当任务失败时，Ansible将立即在该主机上中止play的其余部分并且跳过所有后续任务，但有些时候，可能希望即使在任务失败时也继续执行play

2、忽略任务失败

1️⃣：默认情况下，任务失败时play会中止。不过，可以通过忽略失败的任务来覆盖此行为。可以在任务中使用ignore_errors关键字来实现此目的

演示实例：

//查看playbook
[root@localhost project]# cat playbook.yaml
---
- hosts: all
  gather_facts: no
  tasks:
    - name: install httpd
      yum:
        name: packages      //没有这个包
        state: present
      ignore_errors: yes     //可选｛yes、no｝
 
    - name: shoe some massage
      debug:
        msg: "hello word"
 
 //执行play
[root@localhost project]# ansible-playbook playbook.yaml
 
PLAY [all] ****************************************************************************************************************************************************************
 
TASK [install httpd] ******************************************************************************************************************************************************
fatal: [client.example.com]: FAILED! => {"ansible_facts": {"discovered_interpreter_python": "/usr/libexec/platform-python"}, "changed": false, "failures": ["No package packages available."], "msg": "Failed to install some of the specified packages", "rc": 1, "results": []}
...ignoring         //已经忽略这个任务出错
 
TASK [shoe some massage] **************************************************************************************************************************************************
ok: [client.example.com] => {
    "msg": "hello word"
}
 
PLAY RECAP ****************************************************************************************************************************************************************
client.example.com         : ok=2    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=1   　　

3、任务失败也强制执行处理程序（handlers）

1️⃣：在play中设置force_handlers: yes关键字，则即使play因为后续任务失败而中止也会调用被通知的处理程序（force：促使，推动）

演示实例：

//查看playbook
[root@localhost project]# cat playbook.yaml
---
- hosts: all
  force_handlers: yes     //可选｛yes、no｝
  tasks:
    - name: install httpd
      shell: ls        //这条命令一定会执行成功，从而保证handlers处理程序一定会被触发
      notify:
        - massage
 
    - name: install  httpd
      yum:
        name: packages       //没有这个包，肯定会出错
        state: present
 
  handlers:
    - name: massage
      debug:
        msg: "hello word"
 
 //执行play
[root@localhost project]# ansible-playbook playbook.yaml
 
PLAY [all] ****************************************************************************************************************************************************************
 
TASK [Gathering Facts] ****************************************************************************************************************************************************
ok: [client.example.com]
 
TASK [install httpd] ******************************************************************************************************************************************************
changed: [client.example.com]
 
TASK [install  httpd] *****************************************************************************************************************************************************
fatal: [client.example.com]: FAILED! => {"changed": false, "failures": ["No package packages available."], "msg": "Failed to install some of the specified packages", "rc": 1, "results": []}
 
RUNNING HANDLER [massage] *************************************************************************************************************************************************
ok: [client.example.com] => {
    "msg": "hello word"
}
 
PLAY RECAP ****************************************************************************************************************************************************************
client.example.com         : ok=3    changed=1    unreachable=0    failed=1    skipped=0    rescued=0    ignored=0

2️⃣：处理程序会在任务报告changed结果时获得通知，而在任务报告ok或failed结果时不会获得通知

4、指定任务失败的条件

1️⃣：在任务中使用failed_when关键字来指定表示任务已失败的条件；通常与命令模块搭配使用，这些模块可能成功执行了某一命令，但命令的输出可能指示了失败

演示实例一：使用failed_when关键字

//查看使用的脚本
[root@localhost project]# cat files/test.sh
#!/bin/bash
cat /root       //这句肯定会出错
echo "hello word"
 //注意：在playbook中执行脚本会以最后一个命令作为错误判断标准，中间错误命令不会影响整体的出错，同样也不会因为中间出错而报错
 
 //查看playbook，执行一次看是否成功
[root@localhost project]# cat playbook.yaml
---
- hosts: all
  tasks:
    - name: test
      script:
        files/test.sh
[root@localhost project]# ansible-playbook playbook.yaml
 
PLAY [all] ****************************************************************************************************************************************************************
 
TASK [Gathering Facts] ****************************************************************************************************************************************************
    ok: [client.example.com]
 
TASK [test] ***************************************************************************************************************************************************************
changed: [client.example.com]
 
PLAY RECAP ****************************************************************************************************************************************************************
client.example.com         : ok=2    changed=1    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0  
 //这样无法判断是否都执行成功
 
 //添加任务失败判断语句
[root@localhost project]# cat playbook.yaml
---
- hosts: all
  tasks:
    - name: test
      script:
        files/test.sh
      register: result
      failed_when: "'Is a directory' in result['stdout']"
[root@localhost project]# ansible-playbook playbook.yaml
 
PLAY [all] ****************************************************************************************************************************************************************
 
TASK [Gathering Facts] ****************************************************************************************************************************************************
ok: [client.example.com]
 
TASK [test] ***************************************************************************************************************************************************************
fatal: [client.example.com]: FAILED! => {"changed": true, "failed_when_result": true, "rc": 0, "stderr": "Shared connection to client.example.com closed.\r\n", "stderr_lines": ["Shared connection to client.example.com closed."], "stdout": "cat: /root: Is a directory\r\nhello word\r\n", "stdout_lines": ["cat: /root: Is a directory", "hello word"]}
 
PLAY RECAP ****************************************************************************************************************************************************************
client.example.com         : ok=1    changed=0    unreachable=0    failed=1    skipped=0    rescued=0    ignored=0

2️⃣：fail模块也可用于强制任务失败（主要是将杂乱的提示信息通过自己设置提示方式，达到简单、明了的目的）

演示实例二：

//查看playbook
[root@localhost project]# cat playbook.yaml
---
- hosts: all
  tasks:
    - name: test
      script:
        files/test.sh
      register: result
 
    - fail:
        msg: "There have a failed"
      when: "'Is a directory' in result['stdout']"
 
 //执行play
[root@localhost project]# ansible-playbook playbook.yaml
 
PLAY [all] ****************************************************************************************************************************************************************
 
TASK [Gathering Facts] ****************************************************************************************************************************************************
ok: [client.example.com]
 
TASK [test] ***************************************************************************************************************************************************************
changed: [client.example.com]
 
TASK [fail] ***************************************************************************************************************************************************************
fatal: [client.example.com]: FAILED! => {"changed": false, "msg": "There have a failed"}
 
PLAY RECAP ****************************************************************************************************************************************************************
client.example.com         : ok=2    changed=1    unreachable=0    failed=1    skipped=0    rescued=0    ignored=0

5、指定何时任务报告“changed”结果

1️⃣：当任务对托管主机进行了更改时，会报告 changed 状态并通知处理程序；如果任务不需要进行更改，则会报告ok并且不通知处理程序

2️⃣：使用changed_when关键字可用于控制任务在何时报告它已进行了更改

演示实例一：

//查看playbook
[root@localhost project]# cat playbook.yaml
---
- hosts: all
  tasks:
    - name: test
      shell: echo "hello word"
 
 //执行后发现，每次都是changed
[root@localhost project]# ansible-playbook playbook.yaml
 
PLAY [all] ****************************************************************************************************************************************************************
 
TASK [Gathering Facts] ****************************************************************************************************************************************************
ok: [client.example.com]
 
TASK [test] ***************************************************************************************************************************************************************
changed: [client.example.com]
 
PLAY RECAP ****************************************************************************************************************************************************************
client.example.com         : ok=2    changed=1    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0 
 
 //添加changed_when关键字，以便报告OK
[root@localhost project]# cat playbook.yaml
---
- hosts: all
  tasks:
    - name: test
      shell: echo "hello word"
      changed_when: false      //可选｛true、false｝
[root@localhost project]# ansible-playbook playbook.yaml
 
PLAY [all] ****************************************************************************************************************************************************************
 
TASK [Gathering Facts] ****************************************************************************************************************************************************
ok: [client.example.com]
 
TASK [test] ***************************************************************************************************************************************************************
ok: [client.example.com]
 
PLAY RECAP ****************************************************************************************************************************************************************
client.example.com         : ok=2    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0   　

3️⃣：根据通过已注册变量收集的模块的输出来报告changed

演示实例二：

//查看playbook
[root@localhost project]# cat playbook.yaml
---
- hosts: all
  tasks:
    - name: test
      command: echo "hello word"
      register: result
      changed_when: "'hello word' in result['stdout']"
 
  //执行play
[root@localhost project]# ansible-playbook playbook.yaml
 
PLAY [all] ****************************************************************************************************************************************************************
 
TASK [Gathering Facts] ****************************************************************************************************************************************************
ok: [client.example.com]
 
TASK [test] ***************************************************************************************************************************************************************
changed: [client.example.com]
 
PLAY RECAP ****************************************************************************************************************************************************************
client.example.com         : ok=2    changed=1    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0  
  //因为在result['stdout']中有hello word ，所以被认定为是true，所以就显示changed

6、Ansible块和错误处理

1️⃣：在playbook中，块是对任务进行逻辑分组的子句，可用于控制任务的执行方式

2️⃣：通过块，也可结合rescue和always语句来处理错误。如果块中的任何任务失败，则执行其rescue块中的任务来进行恢复

3️⃣：在block子句中的任务以及rescue子句中的任务（如果出现故障）运行之后，always子句中的任务运行

4️⃣：总结：

block：定义要运行的主要任务
rescue：定义要在block子句中定义的任务失败时运行的任务
always：定义始终都独立运行的任务，不论block和rescue子句中定义的任务是成功还是失败

5️⃣：演示：

演示实例一：当只有block和rescue，且block语句执行成功时，只执行block语句而不执行rescue语句（rescue：营救、救援）

//查看playbook
[root@localhost project]# cat playbook.yaml
---
- hosts: all
  gather_facts: no
  tasks:
    - name: test
      block:
        - name: block
          shell: echo "hello word"
 
      rescue:
        - name: rescue
          shell: ls /root
 
 //执行play
[root@localhost project]# ansible-playbook --syntax-check playbook.yaml
 
playbook: playbook.yaml
[root@localhost project]# an
anacron             ansible-config      ansible-console     ansible-galaxy      ansible-playbook    ansible-test       
ansible             ansible-connection  ansible-doc         ansible-inventory   ansible-pull        ansible-vault      
[root@localhost project]# ansible-playbook playbook.yaml
 
PLAY [all] ****************************************************************************************************************************************************************
 
TASK [block] **************************************************************************************************************************************************************
changed: [client.example.com]
 
PLAY RECAP ****************************************************************************************************************************************************************
client.example.com         : ok=1    changed=1    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0  
 //可以发现，只执行了block语句，并没有执行rescue语句

演示实例二：当只有block和rescue，且block语句执行失败时，不执行block语句而执行rescue语句

//查看playbook
[root@localhost project]# cat playbook.yaml
---
- hosts: all
  gather_facts: no
  tasks:
    - name: test
      block:
        - name: block
          command: cat /        //这句肯定会失败
 
      rescue:
        - name: rescue
          shell: ls /root
 
 //执行play
[root@localhost project]# ansible-playbook playbook.yaml
 
PLAY [all] ****************************************************************************************************************************************************************
 
TASK [block] **************************************************************************************************************************************************************
fatal: [client.example.com]: FAILED! => {"ansible_facts": {"discovered_interpreter_python": "/usr/libexec/platform-python"}, "changed": true, "cmd": ["cat", "/"], "delta": "0:00:00.005350", "end": "2020-09-08 10:59:18.381699", "msg": "non-zero return code", "rc": 1, "start": "2020-09-08 10:59:18.376349", "stderr": "cat: /: Is a directory", "stderr_lines": ["cat: /: Is a directory"], "stdout": "", "stdout_lines": []}
 
TASK [rescue] *************************************************************************************************************************************************************
changed: [client.example.com]
 
PLAY RECAP ****************************************************************************************************************************************************************
client.example.com         : ok=1    changed=1    unreachable=0    failed=0    skipped=0    rescued=1    ignored=0  
 //可以看出，block语句执行失败而执行了rescue语句

演示实例三：当block语句、rescue语句和always语句都有时，无论block语句是否失败，always语句总是执行

//查看playbook
[root@localhost project]# cat playbook.yaml
---
- hosts: all
  gather_facts: no
  tasks:
    - name: test
      block:
        - name: block
          command: cat /
 
      rescue:
        - name: rescue
          shell: ls /root
           
      always:
        - name: always
          debug:
            msg: "This is my test"
 
 //执行play
[root@localhost project]# ansible-playbook playbook.yaml
 
PLAY [all] ****************************************************************************************************************************************************************
 
TASK [block] **************************************************************************************************************************************************************
fatal: [client.example.com]: FAILED! => {"ansible_facts": {"discovered_interpreter_python": "/usr/libexec/platform-python"}, "changed": true, "cmd": ["cat", "/"], "delta": "0:00:00.008993", "end": "2020-09-08 11:05:47.816489", "msg": "non-zero return code", "rc": 1, "start": "2020-09-08 11:05:47.807496", "stderr": "cat: /: Is a directory", "stderr_lines": ["cat: /: Is a directory"], "stdout": "", "stdout_lines": []}
 
TASK [rescue] *************************************************************************************************************************************************************
changed: [client.example.com]
 
TASK [always] *************************************************************************************************************************************************************
ok: [client.example.com] => {
    "msg": "This is my test"
}
 
PLAY RECAP ****************************************************************************************************************************************************************
client.example.com         : ok=2    changed=1    unreachable=0    failed=0    skipped=0    rescued=1    ignored=0

6️⃣：block中的when条件也会应用到其rescue和always子句（若存在）

演示实例一：

//查看playbook
[root@localhost project]# cat playbook.yaml
---
- hosts: all
  gather_facts: no
  tasks:
    - name: test
      block:
        - name: block
          command: echo "hello word"         //该语句没有错误
          when: ansible_facts['distribution'] == "CentOS"      //条件判断出错会导致block语句不会执行
 
      rescue:
        - name: rescue
          shell: ls /root
           
      always:
        - name: always
          debug:
            msg: "This is my test"
 
 //执行play
[root@localhost project]# ansible-playbook playbook.yaml
 
PLAY [all] ****************************************************************************************************************************************************************
 
TASK [block] **************************************************************************************************************************************************************
fatal: [client.example.com]: FAILED! => {"msg": "The conditional check 'ansible_facts['distribution'] == \"CentOS\"' failed. The error was: error while evaluating conditional (ansible_facts['distribution'] == \"CentOS\"): 'dict object' has no attribute 'distribution'\n\nThe error appears to be in '/root/project/playbook.yaml': line 7, column 11, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n      block:\n        - name: block\n          ^ here\n"}
 
TASK [rescue] *************************************************************************************************************************************************************
changed: [client.example.com]
 
TASK [always] *************************************************************************************************************************************************************
ok: [client.example.com] => {
    "msg": "This is my test"
}
 
PLAY RECAP ****************************************************************************************************************************************************************
client.example.com         : ok=2    changed=1    unreachable=0    failed=0    skipped=0    rescued=1    ignored=0   　

演示实例二：

 //查看playbook
[root@localhost project]# cat playbook.yaml 
---
- hosts: all
  gather_facts: no
  tasks:
    - name: test 
      block:
        - name: block
          command: echo "hello word"
          when: ansible_facts['distribution'] == "CentOS"

      rescue:
        - name: rescue
          shell: ls /root
          when: ansible_facts['distribution_major_version'] == "7"    //这句when语句会执行失败，导致rescue语句不会执行
          
      always:
        - name: always
          debug:
            msg: "This is my test"

 //执行play
[root@localhost project]# ansible-playbook playbook.yaml 

PLAY [all] ****************************************************************************************************************************************************************

TASK [block] **************************************************************************************************************************************************************
fatal: [client.example.com]: FAILED! => {"msg": "The conditional check 'ansible_facts['distribution'] == \"CentOS\"' failed. The error was: error while evaluating conditional (ansible_facts['distribution'] == \"CentOS\"): 'dict object' has no attribute 'distribution'\n\nThe error appears to be in '/root/project/playbook.yaml': line 7, column 11, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n      block:\n        - name: block\n          ^ here\n"}

TASK [rescue] *************************************************************************************************************************************************************
fatal: [client.example.com]: FAILED! => {"msg": "The conditional check 'ansible_facts['distribution_major_version'] == \"7\"' failed. The error was: error while evaluating conditional (ansible_facts['distribution_major_version'] == \"7\"): 'dict object' has no attribute 'distribution_major_version'\n\nThe error appears to be in '/root/project/playbook.yaml': line 12, column 11, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n      rescue:\n        - name: rescue\n          ^ here\n"}

TASK [always] *************************************************************************************************************************************************************
ok: [client.example.com] => {
    "msg": "This is my test"
}

PLAY RECAP ****************************************************************************************************************************************************************
client.example.com         : ok=1    changed=0    unreachable=0    failed=1    skipped=0    rescued=1    ignored=0   
 //可以看出，block语句和rescue语句都没执行

演示实例三：

 //查看playbook
[root@localhost project]# cat playbook.yaml 
---
- hosts: all
  gather_facts: no
  tasks:
    - name: test 
      block:
        - name: block
          command: echo "hello word"

      rescue:
        - name: rescue
          shell: ls /root
          
      always:
        - name: always
          debug:
            msg: "This is my test"
          when: ansible_facts['distribution_version'] == "8"   //when条件储出错没回导致always语句执行失败

 //执行play
[root@localhost project]# ansible-playbook playbook.yaml 

PLAY [all] ****************************************************************************************************************************************************************

TASK [block] **************************************************************************************************************************************************************
changed: [client.example.com]

TASK [always] *************************************************************************************************************************************************************
fatal: [client.example.com]: FAILED! => {"msg": "The conditional check 'ansible_facts['distribution_version'] == \"8\"' failed. The error was: error while evaluating conditional (ansible_facts['distribution_version'] == \"8\"): 'dict object' has no attribute 'distribution_version'\n\nThe error appears to be in '/root/project/playbook.yaml': line 15, column 11, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n      always:\n        - name: always\n          ^ here\n"}

PLAY RECAP ****************************************************************************************************************************************************************
client.example.com         : ok=1    changed=1    unreachable=0    failed=1    skipped=0    rescued=0    ignored=0

注意：block执行会成功的话，如果用when条件判断，即使判断条件会成功，但block语句任然会失败，而去执行rescue语句

转自

Ansible_处理失败的任务 - 珍朱奶茶 - 博客园
https://www.cnblogs.com/itwangqiang/p/13629677.html

posted @ 2023-01-04 13:33 paul_hch 阅读(550) 评论(0) 收藏举报

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hch的随笔成功的秘诀在于恒心—迪斯雷利

成功的秘诀在于恒心——迪斯雷利

Ansible_处理失败的任务【转】

一、Ansible处理任务失败

1、管理play中任务错误

3、任务失败也强制执行处理程序（handlers）

4、指定任务失败的条件

5、指定何时任务报告“changed”结果

6、Ansible块和错误处理

公告

hch的随笔 成功的秘诀在于恒心—迪斯雷利

成功的秘诀在于恒心——迪斯雷利

Ansible_处理失败的任务【转】

一、Ansible处理任务失败

1、管理play中任务错误

3、任务失败也强制执行处理程序（handlers）

4、指定任务失败的条件

5、指定何时任务报告“changed”结果

6、Ansible块和错误处理

公告

hch的随笔成功的秘诀在于恒心—迪斯雷利