2.5 获取帮助信息

在Ansible 1.9.2版本中有8个主要的Ansible管理工具，每个管理工具都是一系列的模块、参数支持。随时可获取的帮助信息对了解掌握Ansible系统非常重要。对于Ansible每个工具，都可以简单地在命令后面加上-h或--help直接获取帮助。

例如，列出ansible-doc工具的支持参数。最主要的参数-l列出可使用的模块，-s列出某个模块支持的动作，如下所示：

        [root@ansiblecontrol]# ansible-doc -h
        Usage: ansible-doc [options] [module...]

        Show Ansible module documentation

        Options:
          --version                show program' s version number and exit
          -h, --help               show this help message and exit
          -M MODULE_PATH, --module-path=MODULE_PATH
                                Ansible modules/ directory
          -l, --list               List available modules
          -s, --snippet           Show playbook snippet for specified module(s)
          -v                         Show version number and exit

用ansible-doc -l列出Ansible系统支持的模块，Ansible安装后能够列出259个模块，如下所示

        $ ansible-doc -l
        less 458 (POSIX regular expressions)
        Copyright (C) 1984-2012 Mark Nudelman
        less comes with NO WARRANTY, to the extent permitted by law.
        For information about the terms of redistribution,
        see the file named README in the less distribution.
        Homepage: http://www.greenwoodsoftware.com/less
        a10_server                Manage A10 Networks AX/SoftAX/Thunder/vThunder...
        a10_service_group       Manage A10 Networks AX/SoftAX/Thunder/vThunder...
        a10_virtual_server     Manage A10 Networks AX/SoftAX/Thunder/vThunder...
        acl                        Sets and retrieves file ACL information.
        add_host                  add a host (and alternatively a group) to the ...
        airbrake_deployment    Notify airbrake about app deployments
        alternatives             Manages alternative programs for common comman...
        apache2_module          enables/disables a module of the Apache2 webse...
        apt                        Manages apt-packages
        apt_key                   Add or remove an apt key
        ………

ansible-doc直接加模块名称，将显示该模块的描述和使用示例，如ansible-doc ping。每个模块都有一系列的动作，可以用ansible-doc -s+模块名称列出，如下面列出yum模块的动作：

        $ ansible-doc -s yum
        less 458 (POSIX regular expressions)
        Copyright (C) 1984-2012 Mark Nudelman
        less comes with NO WARRANTY, to the extent permitted by law.
        For information about the terms of redistribution,
        see the file named README in the less distribution.
        Homepage: http://www.greenwoodsoftware.com/less
        - name: Manages pack age swith the I (yum) pac
            action: yum
                conf_file            # The  remote  yum  configuration  file  to  use
                                      for the
                disable_gpg_check  # Whether  to  disable  the  GPG  checking  of
                                      signatures
                disablerepo         # ' Repoid' of repositories to disable for the
                                      insta
                enablerepo          # ' Repoid'  of  repositories  to  enable  for  the
                                      instal
                list                  # Various (non-idempotent) commands for usage
                                      with
                name=                 # Package  name,  or  package  specifier  with
                                      version,
                state                 # Whether  to  install  (`present' ,  `latest' ),
                                      or remo
                update_cache        # Force  updating  the  cache.  Has  an  effect
                                      only if s

另外，在Ansible调试自动化脚本时候经常需要获取执行过程的详细信息，可以在命令后面添加-v或-vvv得到详细的输出结果。如：

        $ansible webservers -i inventory.cfg -m ping -vvv

最后别忘了经常浏览官方网站http://docs.ansible.com/，其中有详细的使用说明。