Ansible默认安装好后有一个配置文件/etc/ansible/ansible.cfg，该配置文件中定义了ansible的主机的默认配置部分，如默认是否需要输入密码、是否开启sudo认证、action_plugins插件的位置、hosts主机组的位置、是否开启log功能、默认端口、key文件位置等等。

具体如下：

 1[defaults]
 2# some basic default values...
 3hostfile       = /etc/ansible/hosts   \\指定默认hosts配置的位置
 4# library_path = /usr/share/my_modules/
 5remote_tmp     = $HOME/.ansible/tmp
 6pattern        = *
 7forks          = 5
 8poll_interval  = 15
 9sudo_user      = root  \\远程sudo用户
10#ask_sudo_pass = True  \\每次执行ansible命令是否询问ssh密码
11#ask_pass      = True  \\每次执行ansible命令时是否询问sudo密码
12transport      = smart
13remote_port    = 22
14module_lang    = C
15gathering = implicit
16host_key_checking = False    \\关闭第一次使用ansible连接客户端是输入命令提示
17log_path    = /var/log/ansible.log \\需要时可以自行添加。chown -R root:root ansible.log
18system_warnings = False    \\关闭运行ansible时系统的提示信息，一般为提示升级
19# set plugin path directories here, separate with colons
20action_plugins     = /usr/share/ansible_plugins/action_plugins
21callback_plugins   = /usr/share/ansible_plugins/callback_plugins
22connection_plugins = /usr/share/ansible_plugins/connection_plugins
23lookup_plugins     = /usr/share/ansible_plugins/lookup_plugins
24vars_plugins       = /usr/share/ansible_plugins/vars_plugins
25filter_plugins     = /usr/share/ansible_plugins/filter_plugins
26fact_caching = memory
27[accelerate]
28accelerate_port = 5099
29accelerate_timeout = 30
30accelerate_connect_timeout = 5.0
31# The daemon timeout is measured in minutes. This time is measured
32# from the last activity to the accelerate daemon.
33accelerate_daemon_timeout = 30

本篇就结合一个示例对其进行下了解。我在对之前未连接的主机进行连结时报错如下：

1[[email protected] ~]# ansible test -a 'uptime'
210.212.52.14 | FAILED => Using a SSH password instead of a key is not possible because Host Key checking is enabled and sshpass does not support this.  Please add this host's fingerprint to your known_hosts file to manage this host.
310.212.52.16 | FAILED => Using a SSH password instead of a key is not possible because Host Key checking is enabled and sshpass does not support this.  Please add this host's fingerprint to your known_hosts file to manage this host.

从上面的输出提示上基本可以了解到由于在本机的~/.ssh/known_hosts文件中并有fingerprint key串，ssh第一次连接的时候一般会提示输入yes 进行确认为将key字符串加入到 ~/.ssh/known_hosts 文件中。

方法1：

了解到问题原因为，我们了解到进行ssh连接时，可以使用-o参数将StrictHostKeyChecking设置为no，使用ssh连接时避免首次连接时让输入yes/no部分的提示。通过查看ansible.cfg配置文件，发现如下行：

1[ssh_connection]
2# ssh arguments to use
3# Leaving off ControlPersist will result in poor performance, so use
4# paramiko on older platforms rather than removing it
5#ssh_args = -o ControlMaster=auto -o ControlPersist=60s

所以这里我们可以启用ssh_args 部分，使用下面的配置，避免上面出现的错误：

1ssh_args = -o ControlMaster=auto -o ControlPersist=60s -o StrictHostKeyChecking＝no

方法2：

在ansible.cfg配置文件中，也会找到如下部分：

1# uncomment this to disable SSH key host checking
2host_key_checking = False

默认host_key_checking部分是注释的，通过找开该行的注释，同样也可以实现跳过 ssh 首次连接提示验证部分。由于配置文件中直接有该选项，所以推荐用方法2 。

其他部分

由于官方给的说明比较详细，同时ansible.cfg 文件本身默认也有注释提示部分，所以不做过多说明，这里再举个例子，默认ansible 执行的时候，并不会输出日志到文件，不过在ansible.cfg 配置文件中有如下行：

1# logging is off by default unless this path is defined
2# if so defined, consider logrotate
3log_path = /var/log/ansible.log

同样，默认log_path这行是注释的，打开该行的注释，所有的命令执行后，都会将日志输出到/var/log/ansible.log 文件，便于了解在何时执行了何操作及其结果，如下：

 1[[email protected] ansible]# cat /var/log/ansible.log
 22015-05-04 01:57:19,758 p=4667 u=root |
 32015-05-04 01:57:19,759 p=4667 u=root |  /usr/bin/ansible test -a uptime
 42015-05-04 01:57:19,759 p=4667 u=root |
 52015-05-04 01:57:20,563 p=4667 u=root |  10.212.52.252 | success | rc=0 >>
 6 01:57am  up 23 days 11:20,  2 users,  load average: 0.38, 0.38, 0.40
 72015-05-04 01:57:20,831 p=4667 u=root |  10.212.52.14 | success | rc=0 >>
 8 02:03am  up 331 days  8:19,  2 users,  load average: 0.08, 0.05, 0.05
 92015-05-04 01:57:20,909 p=4667 u=root |  10.212.52.16 | success | rc=0 >>
10 02:05am  up 331 days  8:56,  2 users,  load average: 0.00, 0.01, 0.05

更多部分可以参看官方文档。