Ansible-Playbook异常处理

1、异常处理说明

在 playbook 执行的过程中，难免会遇到一些错误。由于 playbook 遇到错误后，不会执行之后的任务，不便于调试，此时，可以使用 ignore_errors 来暂时忽略错误，使得 playbook 继续执行。

2、示例1-Playbook错误忽略

2.1、编写 playbook 【当有 task 执行失败则会立即终止后续 task 运行】

cat << 'CAT_END' > ignore.yaml
- hosts: all
  remote_user: root
  tasks:
    - name: Ignore False
      command: /bin/false
      ignore_errors: yes
    - name: touch test.txt
      file: path=/tmp/test.txt state=touch
CAT_END

2.2、执行 playbook 【使用ignore_errors: yes会报错，后续的任务正常执行】

]# ansible-playbook ignore.yaml 

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

TASK [Gathering Facts] ***************************************************************************************************************************************
ok: [192.168.10.15]

TASK [Ignore False] ******************************************************************************************************************************************
fatal: [192.168.10.15]: FAILED! => {"changed": true, "cmd": ["/bin/false"], "delta": "0:00:00.008390", "end": "2023-05-13 22:44:16.521903", "msg": "non-zero return code", "rc": 1, 
"start": "2023-05-13 22:44:16.513513", "stderr": "", "stderr_lines": [], "stdout": "", "stdout_lines": []}
...ignoring

TASK [touch test.txt] ****************************************************************************************************************************************
changed: [192.168.10.15]

PLAY RECAP ***************************************************************************************************************************************************
192.168.10.15              : ok=3    changed=2    unreachable=0    failed=0    skipped=0    rescued=0    ignored=1

3、示例2-task执行失败强制调用handlers

3.1、说明

通常情况下，当 task 失败后， play 将会终止，任何在前面已经被 tasks notify的 handlers 都不会被执行。如果你在 play 中设置了 force_handlers: yes 参数，被通知的 handlers 就会被强制执行。(有些特殊场景可能会使用到) 

3.2、编写 playbook

cat << 'CAT_END' > force_handlers.yaml
- hosts: httpd
  force_handlers: yes
  tasks:
    - name: Touch File
      file: path=/tmp/handler_test state=touch
      notify: restart nginx server
    - name: install package
      yum: name=test state=latest
  handlers:
    - name: restart nginx server
      systemd: name=nginx state=restarted
CAT_END

3.3、执行playbook

]# ansible-playbook force_handlers.yaml 

PLAY [httpd] *************************************************************************************************************************************************

TASK [Gathering Facts] ***************************************************************************************************************************************
ok: [192.168.10.18]
ok: [192.168.10.17]

TASK [Touch File] ********************************************************************************************************************************************
changed: [192.168.10.17]
changed: [192.168.10.18]

TASK [install package] ***************************************************************************************************************************************
fatal: [192.168.10.17]: FAILED! => {"changed": false, "msg": "No package matching 'test' found available, installed or updated", "rc": 126, "results": ["No package matching 'test' found available, installed or updated"]}
fatal: [192.168.10.18]: FAILED! => {"changed": false, "msg": "No package matching 'test' found available, installed or updated", "rc": 126, "results": ["No package matching 'test' found available, installed or updated"]}
# 前者task报错，也不影响handlers的调用
RUNNING HANDLER [restart nginx server] ***********************************************************************************************************************
changed: [192.168.10.17]
changed: [192.168.10.18]

PLAY RECAP ***************************************************************************************************************************************************
192.168.10.17              : ok=3    changed=2    unreachable=0    failed=1    skipped=0    rescued=0    ignored=0   
192.168.10.18              : ok=3    changed=2    unreachable=0    failed=1    skipped=0    rescued=0    ignored=0

4、示例3-控制Tasks报告状态为OK

4.1、编辑 playbook

cat << 'CAT_END' > change_status.yaml
- hosts: httpd
  force_handlers: yes
  tasks:
    - name: get nginx server port
      shell: netstat -tunlp | grep nginx
      register: nginx_port
    - name: out nginx server status
      debug: msg={{nginx_port.stdout_lines}}
      ignore_errors: yes
CAT_END

4.2、执行playbokk

]# ansible-playbook change_status.yaml 

PLAY [httpd] *************************************************************************************************************************************************

TASK [Gathering Facts] ***************************************************************************************************************************************
ok: [192.168.10.18]
ok: [192.168.10.17]

TASK [get nginx server port] *********************************************************************************************************************************
changed: [192.168.10.18]
changed: [192.168.10.17] # 发现这里没有状态

TASK [out nginx server status] *******************************************************************************************************************************
ok: [192.168.10.17] => {
    "msg": [
        "tcp        0      0 0.0.0.0:80              0.0.0.0:*               LISTEN      20372/nginx: master ", 
        "tcp6       0      0 :::80                   :::*                    LISTEN      20372/nginx: master "
    ]
}
ok: [192.168.10.18] => {
    "msg": [
        "tcp        0      0 0.0.0.0:80              0.0.0.0:*               LISTEN      54183/nginx: master ", 
        "tcp6       0      0 :::80                   :::*                    LISTEN      54183/nginx: master "
    ]
}

PLAY RECAP ***************************************************************************************************************************************************
192.168.10.17              : ok=3    changed=1    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0   
192.168.10.18              : ok=3    changed=1    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

4.3、shell 任务不应该每次都报告 changed 状态，因为它没有在被管理主机执行后发生变化

# 添加 changed_when: false 来抑制这个改变
cat << 'CAT_END' > change_when_status.yaml
- hosts: httpd
  force_handlers: yes
  tasks:
    - name: get nginx server port
      shell: netstat -tunlp | grep nginx
      register: nginx_port
      changed_when: false # 关闭change提示
    - name: out nginx server status
      debug: msg={{nginx_port.stdout_lines}}
      ignore_errors: yes
CAT_END

4.4、执行playbook

]# ansible-playbook change_when_status.yaml 

PLAY [httpd] *************************************************************************************************************************************************

TASK [Gathering Facts] ***************************************************************************************************************************************
ok: [192.168.10.17]
ok: [192.168.10.18]

TASK [get nginx server port] *********************************************************************************************************************************
ok: [192.168.10.17]
ok: [192.168.10.18] # 发现状态，已经变ok

TASK [out nginx server status] *******************************************************************************************************************************
ok: [192.168.10.17] => {
    "msg": [
        "tcp        0      0 0.0.0.0:80              0.0.0.0:*               LISTEN      20372/nginx: master ", 
        "tcp6       0      0 :::80                   :::*                    LISTEN      20372/nginx: master "
    ]
}
ok: [192.168.10.18] => {
    "msg": [
        "tcp        0      0 0.0.0.0:80              0.0.0.0:*               LISTEN      54183/nginx: master ", 
        "tcp6       0      0 :::80                   :::*                    LISTEN      54183/nginx: master "
    ]
}

PLAY RECAP ***************************************************************************************************************************************************
192.168.10.17              : ok=3    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0   
192.168.10.18              : ok=3    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

5、示例4-changed_when检查任务结果

5.1、httpd-playbook

cat <<'CAT_END'>change_when.yaml
- hosts: httpd
  tasks:
    - name: configure httpd server
      template: src=./httpd.conf.j2 dest=/etc/httpd/conf/httpd.conf
      notify: restart httpd server
    - name: check httpd syntax
      shell: /usr/sbin/httpd -t
      register: httpd_check
      change_when:
        - httpd_check.stdout.find('OK') # 查找变量返回的结果是否有ok，如不存在则终止该tasks
        - false # 被管理主机没有发生变化状态则为OK
    - name: start httpd server
      systemd: name=httpd state=present enabled=yes
  handlers:
    - name: restart httpd server
      systemd: name=httpd state=restarted
CAT_END

5.2、nginx-playbook

cat <<'CAT_END'>change_when.yaml
- hosts: httpd
  tasks:
    - name: install nginx server
      yum: name=nginx state=present
    - name: configure nginx server
      template: src=./nginx.conf.j2 dest=/etc/nginx/nginx.conf
      notify: restart nginx server
    - name: check nginx syntax
      shell: /usr/sbin/nginx -t
      register: nginx_check
      change_when:
        - nginx_check.stdout.find('successful') # 查找变量返回的结果是否有ok，如不存在则终止该tasks
        - false # 被管理主机没有发生变化状态则为OK
    - name: start nginx server
      systemd: name=nginx state=present enabled=yes
  handlers:
    - name: restart nginx server
      systemd: name=nginx state=restarted
CAT_END

 

posted @ 2023-05-14 11:41  小粉优化大师  阅读(622)  评论(0)    收藏  举报