ansible小结（四）ansible.cfg与默认配置

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…
3. hostfile = /etc/ansible/hosts \\指定默认hosts配置的位置
4. # library_path = /usr/share/my_modules/
5. remote_tmp = $HOME/.ansible/tmp
6. pattern = *
7. forks = 5
8. poll_interval = 15
9. sudo_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
12. transport = smart
13. remote_port = 22
14. module_lang = C
15. gathering = implicit
16. host_key_checking = False \\关闭第一次使用ansible连接客户端是输入命令提示
17. log_path = /var/log/ansible.log \\需要时可以自行添加。chown -R root:root ansible.log
18. system_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
20. action_plugins = /usr/share/ansible_plugins/action_plugins
21. callback_plugins = /usr/share/ansible_plugins/callback_plugins
22. connection_plugins = /usr/share/ansible_plugins/connection_plugins
23. lookup_plugins = /usr/share/ansible_plugins/lookup_plugins
24. vars_plugins = /usr/share/ansible_plugins/vars_plugins
25. filter_plugins = /usr/share/ansible_plugins/filter_plugins
26. fact_caching = memory
27. [accelerate]
28. accelerate_port = 5099
29. accelerate_timeout = 30
30. accelerate_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.
33. 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：

1. [root@361way.com ~]# ansible test -a ‘uptime’
2. 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.
3. 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。

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：

1. ssh_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
2. 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：

1. # logging is off by default unless this path is defined
2. # if so defined, consider logrotate
3. 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：

1. [root@361way.com ansible]# cat /var/log/ansible.log
2. 2015–05–04 01:57:19,758 p=4667 u=root |
3. 2015–05–04 01:57:19,759 p=4667 u=root | /usr/bin/ansible test –a uptime
4. 2015–05–04 01:57:19,759 p=4667 u=root |
5. 2015–05–04 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
7. 2015–05–04 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
9. 2015–05–04 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。