ansible-playbook之block

Ansible在2.0版本引入块功能，块功能可以将任务进行分组，并且可以块级别上应用任务变量，同时支持在块内进行异常处理

常用语法：

    - block:定义块

      rescue:当出现异常时，执行的语句

      always:无论结果如何都要执行的语句

块用法示例：

[root@nfs-server playbook] # cat block.yml
---
- hosts: webservers
  remote_user: root
  gather_facts: True
  tasks:
  - block:
      - service: name={{ item }} state=stopped
        with_items:
          - nginx
          - httpd
          - memcached
        tags:
          - stop_application
      - yum: name={{ item }} state=absent
        with_items:
          - nginx
          - httpd
          - memcached
        tags:
          - remove_soft
    when: ansible_os_family ==  'RedHat'
[root@nfs-server playbook] # ansible-playbook block.yml

PLAY [webservers] **************************************************************************************************************************************

TASK [Gathering Facts] *********************************************************************************************************************************
ok: [192.168.2.111]
ok: [192.168.2.101]

TASK [service] *****************************************************************************************************************************************
changed: [192.168.2.101] => (item=nginx)
changed: [192.168.2.111] => (item=nginx)
ok: [192.168.2.101] => (item=httpd)
ok: [192.168.2.111] => (item=httpd)
changed: [192.168.2.111] => (item=memcached)
changed: [192.168.2.101] => (item=memcached)

TASK [yum] *********************************************************************************************************************************************
changed: [192.168.2.101] => (item=[u 'nginx' , u 'httpd' , u 'memcached' ])
changed: [192.168.2.111] => (item=[u 'nginx' , u 'httpd' , u 'memcached' ])

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