ansible的ansible.cfg配置介绍

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：

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

[root@361way.com ~]# ansible test -a 'uptime'
10.212.52.14 | 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.
10.212.52.16 | 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。

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：

[ssh_connection]
# ssh arguments to use
# Leaving off ControlPersist will result in poor performance, so use
# paramiko on older platforms rather than removing it
#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：

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

在ansible.cfg配置文件中，也会找到如下部分：

# uncomment this to disable SSH key host checking
host_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：

# logging is off by default unless this path is defined
# if so defined, consider logrotate
log_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：

[root@361way.com ansible]# cat /var/log/ansible.log
2015-05-04 01:57:19,758 p=4667 u=root |
2015-05-04 01:57:19,759 p=4667 u=root | /usr/bin/ansible test -a uptime
2015-05-04 01:57:19,759 p=4667 u=root |
2015-05-04 01:57:20,563 p=4667 u=root | 10.212.52.252 | success | rc=0 >>
01:57am up 23 days 11:20, 2 users, load average: 0.38, 0.38, 0.40
2015-05-04 01:57:20,831 p=4667 u=root | 10.212.52.14 | success | rc=0 >>
02:03am up 331 days 8:19, 2 users, load average: 0.08, 0.05, 0.05
2015-05-04 01:57:20,909 p=4667 u=root | 10.212.52.16 | success | rc=0 >>
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。