Ad-Hoc 是指ansible下临时执行的一条命令，并且不需要保存的命令，对于复杂的命令后面会说playbook。讲到Ad-hoc 就要提到模块，所有的命令执行都要依赖于事先写好的模块，默认安装好的ansible 里面已经自带了很多模块，如：command、raw、shell、file、cron等，具体可以通过ansible-doc -l 进行查看 。

一、Ad-hoc

1、直接执行

这里还是先来一个上几篇幅经常用到的一个例子：

1[root@361way ~]# ansible 10.212.52.252 -a 'uptime' -k
2SSH password:
310.212.52.252 | success | rc=0 >>
4 10:10am  up 27 days 19:33,  2 users,  load average: 0.39, 0.34, 0.33

一个ad-hoc命令的执行，需要按以下格式进行执行：ansible 主机或组 -m 模块名 -a '模块参数' ansible参数

  • 主机和组，是在/etc/ansible/hosts 里进行指定的部分，当然动态Inventory 使用的是脚本从外部应用里获取的主机，这部分具体可以参考ansible小结（五）Dynamic Inventory ；
  • 模块名，可以通过ansible-doc -l 查看目前安装的模块，默认不指定时，使用的是command模块，具体可以查看/etc/ansible/ansible.cfg 的“#module_name = command ” 部分，默认模块可以在该配置文件中进行修改；
  • 模块参数，可以通过 “ansible-doc 模块名” 查看具体的用法及后面的参数；
  • ansible参数，可以通过ansible命令的帮忙信息里查看到，这里有很多参数可以供选择，如是否需要输入密码、是否sudo等。

2、后台执行

当命令执行时间比较长时，也可以放到后台执行，这里会用到-B、-P参数，如下：

1ansible all -B 3600 -a "/usr/bin/long_running_operation --do-stuff" \\后台执行命令 3600s，-B 表示后台执行的时间
2ansible all -m async_status -a "jid=123456789"  \\检查任务的状态
3ansible all -B 1800 -P 60 -a "/usr/bin/long_running_operation --do-stuff" \\后台执行命令最大时间是 1800s 即 30 分钟，-P 每 60s 检查下状态默认 15s

示例如下：

 1[root@361way ~]# ansible 10.212.52.252 -B 3600 -P 0 -a 'watch ls'
 2background launch...
 310.212.52.252 | success >> {
 4    "ansible_job_id": "411650646689.13501",
 5    "results_file": "/root/.ansible_async/411650646689.13501",
 6    "started": 1
 7}
 8[root@361way ~]# ansible 10.212.52.252 -m async_status -a 'jid=411650646689.13501'
 910.212.52.252 | success >> {
10    "ansible_job_id": "411650646689.13501",
11    "changed": false,
12    "finished": 0,
13    "results_file": "/root/.ansible_async/411650646689.13501",
14    "started": 1
15}

不指定-P或-P参数为非0时，该任务就会按-P直接的参数一直刷新下去，直到超出-B参数指定的时间或命令执行完成：

 1[root@361way ~]# ansible 10.212.52.252 -B 3600  -a 'watch ls'
 2background launch...
 310.212.52.252 | success >> {
 4    "ansible_job_id": "397200656414.15008",
 5    "results_file": "/root/.ansible_async/397200656414.15008",
 6    "started": 1
 7}
 810.212.52.252 | success >> {
 9    "ansible_job_id": "397200656414.15008",
10    "changed": false,
11    "finished": 0,
12    "results_file": "/root/.ansible_async/397200656414.15008",
13    "started": 1
14}
15<job 397200656414.15008> polling on 10.212.52.252, 3585s remaining
16…………………………………………略

二、commands模块

上面已经提到，ansbile自身已经自带了很多模块，可以通过ansible-doc -l 进行查看。这里就结合command、shell、raw、script模块了解下其用法。

上面四个模块都属于commands 类。

  • command模块，该模块通过-a跟上要执行的命令可以直接执行，不过命令里如果有带有如下字符部分则执行不成功 “ so variables like $HOME and operations like “<“, “>”, “|”, and “&” will not work (use the shell module if you need these features).”；
  • shell 模块，用法其本和command一样，不过的是其是通过/bin/sh进行执行，所以shell 模块可以执行任何命令，就像在本机执行一样，“ It is almost exactly like the command module but runs the command through a shell (/bin/sh) on the remote node.”；
  • raw模块，用法和shell 模块一样 ，其也可以执行任意命令，就像在本机执行一样，“Executes a low-down and dirty SSH command, not going through the module subsystem. There is no change handler support for this module. This module does not require python on the remote system”
  • script模块，其是将管理端的shell 在被管理主机上执行，其原理是先将shell 复制到远程主机，再在远程主机上执行，原理类似于raw模块，“This module does not require python on the remote system, much like the raw module.” 。

注：raw模块和comand、shell 模块不同的是其没有chdir、creates、removes参数，chdir参数的作用就是先切到chdir指定的目录后，再执行后面的命令，这在后面很多模块里都会有该参数 。

command模块包含如下选项：

  • creates：一个文件名，当该文件存在，则该命令不执行
  • free_form：要执行的linux指令
  • chdir：在执行指令之前，先切换到该指定的目录
  • removes：一个文件名，当该文件不存在，则该选项不执行
  • executable：切换shell来执行指令，该执行路径必须是一个绝对路径

command模块、raw模块、shell模块示例：

 1[root@361way ~]# ansible 10.212.52.252 -m command -a 'ps auxf|grep snmp'
 210.212.52.252 | FAILED | rc=1 >>
 3ERROR: Unsupported option (BSD syntax)
 4********* simple selection *********  ********* selection by list *********
 5-A all processes                      -C by command name
 6-N negate selection                   -G by real group ID (supports names)
 7-a all w/ tty except session leaders  -U by real user ID (supports names)
 8-d all except session leaders         -g by session OR by effective group name
 9-e all processes                      -p by process ID
10T  all processes on this terminal     -s processes in the sessions given
11a  all w/ tty, including other users  -t by tty
12g  OBSOLETE -- DO NOT USE             -u by effective user ID (supports names)
13r  only running processes             U  processes for specified users
14x  processes w/o controlling ttys     t  by tty
15*********** output format **********  *********** long options ***********
16-o,o user-defined  -f full            --Group --User --pid --cols --ppid
17-j,j job control   s  signal          --group --user --sid --rows --info
18-O,O preloaded -o  v  virtual memory  --cumulative --format --deselect
19-l,l long          u  user-oriented   --sort --tty --forest --version
20-F   extra full    X  registers       --heading --no-heading --context
21                    ********* misc options *********
22-V,V  show version      L  list format codes  f  ASCII art forest
23-m,m,-L,-T,H  threads   S  children in sum    -y change -l format
24-M,Z  security data     c  true command name  -c scheduling class
25-w,w  wide output       n  numeric WCHAN,UID  -H process hierarchy
26[root@361way ~]# ansible 10.212.52.252 -m raw -a 'ps auxf|grep snmp'
2710.212.52.252 | success | rc=0 >>
28root      5580 25.0  0.0  12876  1792 pts/2    Ss+  12:36   0:00      \_ bash -c ps auxf|grep snmp
29root      5607  0.0  0.0   5720   832 pts/2    S+   12:36   0:00          \_ grep snmp
30root     24364  0.0  0.0  70416  6696 ?        SNl  May15   0:22 /usr/sbin/snmpd -r -A -LF i /var/log/net-snmpd.log -p /var/run/snmpd.pid
31[root@361way ~]# ansible 10.212.52.252 -m shell -a 'ps auxf|grep snmp'
3210.212.52.252 | success | rc=0 >>
33root      5803  0.0  0.0  11308  1308 pts/2    S+   12:36   0:00              \_ /bin/sh -c ps auxf|grep snmp
34root      5805  0.0  0.0   4260   572 pts/2    S+   12:36   0:00                  \_ grep snmp
35root     24364  0.0  0.0  70416  6696 ?        SNl  May15   0:22 /usr/sbin/snmpd -r -A -LF i /var/log/net-snmpd.log -p /var/run/snmpd.pid

上面的执行结果可以看到，我这里加了管道，command模块执行时出错，而使用raw模块和shell 模块都正常。

使用chdir的示例：

1[root@361way ~]# ansible 10.212.52.252 -m command -a 'chdir=/tmp/361way touch test.file'
210.212.52.252 | success | rc=0 >>
3[root@361way ~]# ansible 10.212.52.252 -m shell -a 'chdir=/tmp/361way touch test2.file'
410.212.52.252 | success | rc=0 >>
5[root@361way ~]# ansible 10.212.52.252 -m raw -a 'chdir=/tmp/361way touch test3.file'
610.212.52.252 | success | rc=0 >>

从上面执行结果来看，三个命令都执行成功了。不过通过在远程主机上查看，前两个文件被成功创建：

1linux-wdh1:/tmp/361way # ls /tmp/361way
2test.file  test2.file

使用raw模块的执行的结果文件也被正常创建了，不过不是在chdir 指定的目录，而是在当前执行用户的家目录。

1linux-wdh1:~ # ls ~/test3.file
2/root/test3.file

creates与removes示例：

这里我在测试主机上创建/tmp/361way/server.txt文件，执行结果如下：

1[root@361way ~]# ansible 10.212.52.252 -a 'creates=/tmp/361way/server.txt uptime'
210.212.52.252 | success | rc=0 >>
3skipped, since /tmp/361way/server.txt exists
4[root@361way ~]# ansible 10.212.52.252 -a 'removes=/tmp/361way/server.txt uptime'
510.212.52.252 | success | rc=0 >>
6 15:11pm  up 28 days  0:34,  2 users,  load average: 0.75, 0.46, 0.39

script模块示例：

 1[root@361way ~]# cat script.sh
 2#!/bin/bash
 3df -hl
 4ifconfig
 5ps auxf|grep snmp
 6[root@361way ~]# ansible 10.212.52.252 -m script -a 'scrip.sh'
 710.212.52.252 | FAILED => file or module does not exist: /root/scrip.sh
 8[root@361way ~]# ansible 10.212.52.252 -m script -a 'script.sh'
 910.212.52.252 | success >> {
10    "changed": true,
11    "rc": 0,
12    "stderr": "OpenSSH_5.3p1, OpenSSL 1.0.1e-fips 11 Feb 2013\ndebug1: Reading configuration data /etc/ssh/ssh_config\r\ndebug1: Applying options for *\r\ndebug1: auto-mux: Trying existing master\r\nControl socket connect(/root/.ansible/cp/ansible-ssh-10.212.52.252-22-root): Connection refused\r\ndebug1: Connecting to 10.212.52.252 [10.212.52.252] port 22.\r\ndebug1: fd 3 clearing O_NONBLOCK\r\ndebug1: Connection established.\r\ndebug1: permanently_set_uid: 0/0\r\ndebug1: identity file /root/.ssh/identity type -1\r\ndebug1: identity file /root/.ssh/identity-cert type -1\r\ndebug1: identity file /root/.ssh/id_rsa type -1\r\ndebug1: identity file /root/.ssh/id_rsa-cert type -1\r\ndebug1: identity file /root/.ssh/id_dsa type -1\r\ndebug1: identity file /root/.ssh/id_dsa-cert type -1\r\ndebug1: identity file /root/.ssh/id_ecdsa type -1\r\ndebug1: identity file /root/.ssh/id_ecdsa-cert type -1\r\ndebug1: Remote protocol version 2.0, remote software version OpenSSH_6.2\r\ndebug1: match: OpenSSH_6.2 pat OpenSSH*\r\ndebug1: Enabling compatibility mode for protocol 2.0\r\ndebug1: Local version string SSH-2.0-OpenSSH_5.3\r\ndebug1: SSH2_MSG_KEXINIT sent\r\ndebug1: SSH2_MSG_KEXINIT received\r\ndebug1: kex: server->client aes128-ctr hmac-md5 zlib@openssh.com\r\ndebug1: kex: client->server aes128-ctr hmac-md5 zlib@openssh.com\r\ndebug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent\r\ndebug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP\r\ndebug1: SSH2_MSG_KEX_DH_GEX_INIT sent\r\ndebug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY\r\ndebug1: Host '10.212.52.252' is known and matches the RSA host key.\r\ndebug1: Found key in /root/.ssh/known_hosts:1\r\ndebug1: ssh_rsa_verify: signature correct\r\ndebug1: SSH2_MSG_NEWKEYS sent\r\ndebug1: expecting SSH2_MSG_NEWKEYS\r\ndebug1: SSH2_MSG_NEWKEYS received\r\ndebug1: SSH2_MSG_SERVICE_REQUEST sent\r\ndebug1: SSH2_MSG_SERVICE_ACCEPT received\r\ndebug1: Authentications that can continue: publickey,password,keyboard-interactive\r\ndebug1: Next authentication method: keyboard-interactive\r\ndebug1: Enabling compression at level 6.\r\ndebug1: Authentication succeeded (keyboard-interactive).\r\ndebug1: setting up multiplex master socket\r\nControlSocket /root/.ansible/cp/ansible-ssh-10.212.52.252-22-root already exists, disabling multiplexing\r\ndebug1: channel 0: new [client-session]\r\ndebug1: Requesting no-more-sessions@openssh.com\r\ndebug1: Entering interactive session.\r\ndebug1: Sending environment.\r\ndebug1: Sending env LANG = en_US.UTF-8\r\ndebug1: Sending command: LANG=C LC_CTYPE=C /root/.ansible/tmp/ansible-tmp-1431924855.88-242473611260231/script.sh \r\ndebug1: client_input_channel_req: channel 0 rtype exit-status reply 0\r\ndebug1: client_input_channel_req: channel 0 rtype eow@openssh.com reply 0\r\ndebug1: channel 0: free: client-session, nchannels 1\r\ndebug1: fd 1 clearing O_NONBLOCK\r\ndebug1: fd 2 clearing O_NONBLOCK\r\nConnection to 10.212.52.252 closed.\r\nTransferred: sent 1928, received 3920 bytes, in 0.1 seconds\r\nBytes per second: sent 37017.0, received 75262.7\r\ndebug1: Exit status 0\r\ndebug1: compress outgoing: raw data 537, compressed 375, factor 0.70\r\ndebug1: compress incoming: raw data 1837, compressed 1019, factor 0.55\r\n",
13    "stdout": "Filesystem      Size  Used Avail Use% Mounted on\r\n/dev/sda2       9.9G  872M  8.5G  10% /\r\nudev            3.9G  128K  3.9G   1% /dev\r\ntmpfs           3.9G   76K  3.9G   1% /dev/shm\r\n/dev/sda3       5.0G  219M  4.5G   5% /boot\r\n/dev/sda8        40G   15G   23G  40% /home\r\n/dev/sda9       9.9G  5.2G  4.3G  55% /opt\r\n/dev/sda6       5.0G  2.7G  2.1G  57% /tmp\r\n/dev/sda5       9.9G  3.4G  6.0G  36% /usr\r\n/dev/sda7       9.9G  823M  8.6G   9% /var\r\neth0      Link encap:Ethernet  HWaddr 00:50:56:A8:65:7E  \r\n          inet addr:10.212.52.252  Bcast:10.212.52.255  Mask:255.255.255.0\r\n          inet6 addr: fe80::250:56ff:fea8:657e/64 Scope:Link\r\n          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1\r\n          RX packets:24112135 errors:0 dropped:792372 overruns:0 frame:0\r\n          TX packets:10697339 errors:0 dropped:0 overruns:0 carrier:0\r\n          collisions:0 txqueuelen:1000 \r\n          RX bytes:17137233328 (16343.3 Mb)  TX bytes:13390377826 (12770.0 Mb)\r\n\r\nlo        Link encap:Local Loopback  \r\n          inet addr:127.0.0.1  Mask:255.0.0.0\r\n          inet6 addr: ::1/128 Scope:Host\r\n          UP LOOPBACK RUNNING  MTU:16436  Metric:1\r\n          RX packets:3407332 errors:0 dropped:0 overruns:0 frame:0\r\n          TX packets:3407332 errors:0 dropped:0 overruns:0 carrier:0\r\n          collisions:0 txqueuelen:0 \r\n          RX bytes:262675450 (250.5 Mb)  TX bytes:262675450 (250.5 Mb)\r\n\r\nroot     25332  0.0  0.0   4260   568 pts/2    S+   12:54   0:00          \\_ grep snmp\r\nroot     24364  0.0  0.0  70416  6696 ?        SNl  May15   0:22 /usr/sbin/snmpd -r -A -LF i /var/log/net-snmpd.log -p /var/run/snmpd.pid\r\n"
14}

输出结果很多，看起来也很乱，不过查下stdout部分，这个部分是实际上执行后的结果。这里可以配合管道一起使用，可以如下使用：

1[root@361way ~]# ansible 10.212.52.252 -m script -a 'script.sh' |egrep '>>|stdout'

篇幅所限，本来想把常用模块都放在该篇来写，感觉太冗长，后面再单独分开相应的篇幅做模块的介绍。