Ad-Hoc 是指ansible下臨時執(zhí)行的一條命令，并且不需要保存的命令，對于復雜的命令后面會說playbook。講到Ad-hoc 就要提到模塊，所有的命令執(zhí)行都要依賴于事先寫好的模塊，默認安裝好的ansible 里面已經(jīng)自帶了很多模塊，如：command、raw、shell、file、cron等，具體可以通過ansible-doc -l 進行查看 。

這里還是先來一個上幾篇幅經(jīng)常用到的一個例子：

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

一個ad-hoc命令的執(zhí)行，需要按以下格式進行執(zhí)行：

1. ansible 主機或組 -m 模塊名 -a '模塊參數(shù)' ansible參數(shù)

• 主機和組，是在/etc/ansible/hosts 里進行指定的部分，當然動態(tài)Inventory 使用的是腳本從外部應用里獲取的主機，這部分具體可以參考ansible小結(jié)（五）Dynamic Inventory ；
• 模塊名，可以通過ansible-doc -l 查看目前安裝的模塊，默認不指定時，使用的是command模塊，具體可以查看/etc/ansible/ansible.cfg 的“#module_name = command ” 部分，默認模塊可以在該配置文件中進行修改；
• 模塊參數(shù)，可以通過 “ansible-doc 模塊名” 查看具體的用法及后面的參數(shù)；
• ansible參數(shù)，可以通過ansible命令的幫忙信息里查看到，這里有很多參數(shù)可以供選擇，如是否需要輸入密碼、是否sudo等。

當命令執(zhí)行時間比較長時，也可以放到后臺執(zhí)行，這里會用到-B、-P參數(shù)，如下：

ansible all -B 3600 -a "/usr/bin/long_running_operation --do-stuff" 
\\后臺執(zhí)行命令 3600s，-B 表示后臺執(zhí)行的時間
ansible all -m async_status -a "jid=123456789" 
\\檢查任務的狀態(tài)
ansible all -B 1800 -P 60 -a "/usr/bin/long_running_operation --do-stuff" 
\\后臺執(zhí)行命令最大時間是 1800s 即 30 分鐘，-P 每 60s 檢查下狀態(tài)默認 15s

示例如下：

[root@361way ~]# ansible 10.212.52.252 -B 3600 -P 0 -a 'watch ls'
background launch...
10.212.52.252 | success >> {
"ansible_job_id": "411650646689.13501",
"results_file": "/root/.ansible_async/411650646689.13501",
"started": 1
}
[root@361way ~]# ansible 10.212.52.252 -m async_status -a 'jid=411650646689.13501'
10.212.52.252 | success >> {
"ansible_job_id": "411650646689.13501",
"changed": false,
"finished": 0,
"results_file": "/root/.ansible_async/411650646689.13501",
"started": 1
}

不指定-P或-P參數(shù)為非0時，該任務就會按-P直接的參數(shù)一直刷新下去，直到超出-B參數(shù)指定的時間或命令執(zhí)行完成：

[root@361way ~]# ansible 10.212.52.252 -B 3600 -a 'watch ls'
background launch...
10.212.52.252 | success >> {
"ansible_job_id": "397200656414.15008",
"results_file": "/root/.ansible_async/397200656414.15008",
"started": 1
}
10.212.52.252 | success >> {
"ansible_job_id": "397200656414.15008",
"changed": false,
"finished": 0,
"results_file": "/root/.ansible_async/397200656414.15008",
"started": 1
}
 polling on 10.212.52.252, 3585s remaining
…………………………………………略

上面已經(jīng)提到，ansbile自身已經(jīng)自帶了很多模塊，可以通過ansible-doc -l 進行查看。這里就結(jié)合command、shell、raw、script模塊了解下其用法。

上面四個模塊都屬于commands 類。

• command模塊，該模塊通過-a跟上要執(zhí)行的命令可以直接執(zhí)行，不過命令里如果有帶有如下字符部分則執(zhí)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 模塊，用法其本和command一樣，不過的是其是通過/bin/sh進行執(zhí)行，所以shell 模塊可以執(zhí)行任何命令，就像在本機執(zhí)行一樣，“ It is almost exactly like the command module but runs the command through a shell (/bin/sh) on the remote node.”；
• raw模塊，用法和shell 模塊一樣 ，其也可以執(zhí)行任意命令，就像在本機執(zhí)行一樣，“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模塊，其是將管理端的shell 在被管理主機上執(zhí)行，其原理是先將shell 復制到遠程主機，再在遠程主機上執(zhí)行，原理類似于raw模塊，“This module does not require python on the remote system, much like the raw module.” 。

注：raw模塊和comand、shell 模塊不同的是其沒有chdir、creates、removes參數(shù)，chdir參數(shù)的作用就是先切到chdir指定的目錄后，再執(zhí)行后面的命令，這在后面很多模塊里都會有該參數(shù)?。

command模塊包含如下選項：

• creates：一個文件名，當該文件存在，則該命令不執(zhí)行
• free_form：要執(zhí)行的linux指令
• chdir：在執(zhí)行指令之前，先切換到該指定的目錄
• removes：一個文件名，當該文件不存在，則該選項不執(zhí)行
• executable：切換shell來執(zhí)行指令，該執(zhí)行路徑必須是一個絕對路徑

command模塊、raw模塊、shell模塊示例：

[root@361way ~]# ansible 10.212.52.252 -m command -a 'ps auxf|grep snmp'
10.212.52.252 | FAILED | rc=1 >>
ERROR: Unsupported option (BSD syntax)
********* simple selection ********* ********* selection by list *********
-A all processes -C by command name
-N negate selection -G by real group ID (supports names)
-a all w/ tty except session leaders -U by real user ID (supports names)
-d all except session leaders -g by session OR by effective group name
-e all processes -p by process ID
T all processes on this terminal -s processes in the sessions given
a all w/ tty, including other users -t by tty
g OBSOLETE -- DO NOT USE -u by effective user ID (supports names)
r only running processes U processes for specified users
x processes w/o controlling ttys t by tty
*********** output format ********** *********** long options ***********
-o,o user-defined -f full --Group --User --pid --cols --ppid
-j,j job control s signal --group --user --sid --rows --info
-O,O preloaded -o v virtual memory --cumulative --format --deselect
-l,l long u user-oriented --sort --tty --forest --version
-F extra full X registers --heading --no-heading --context
********* misc options *********
-V,V show version L list format codes f ASCII art forest
-m,m,-L,-T,H threads S children in sum -y change -l format
-M,Z security data c true command name -c scheduling class
-w,w wide output n numeric WCHAN,UID -H process hierarchy
[root@361way ~]# ansible 10.212.52.252 -m raw -a 'ps auxf|grep snmp'
10.212.52.252 | success | rc=0 >>
root 5580 25.0 0.0 12876 1792 pts/2 Ss+ 12:36 0:00 \_ bash -c ps auxf|grep snmp
root 5607 0.0 0.0 5720 832 pts/2 S+ 12:36 0:00 \_ grep snmp
root 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
[root@361way ~]# ansible 10.212.52.252 -m shell -a 'ps auxf|grep snmp'
10.212.52.252 | success | rc=0 >>
root 5803 0.0 0.0 11308 1308 pts/2 S+ 12:36 0:00 \_ /bin/sh -c ps auxf|grep snmp
root 5805 0.0 0.0 4260 572 pts/2 S+ 12:36 0:00 \_ grep snmp
root 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

上面的執(zhí)行結(jié)果可以看到，我這里加了管道，command模塊執(zhí)行時出錯，而使用raw模塊和shell 模塊都正常。

使用chdir的示例：

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

從上面執(zhí)行結(jié)果來看，三個命令都執(zhí)行成功了。不過通過在遠程主機上查看，前兩個文件被成功創(chuàng)建：

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

使用raw模塊的執(zhí)行的結(jié)果文件也被正常創(chuàng)建了，不過不是在chdir 指定的目錄，而是在當前執(zhí)行用戶的家目錄。

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

creates與removes示例：

這里我在測試主機上創(chuàng)建/tmp/361way/server.txt文件，執(zhí)行結(jié)果如下：

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

script模塊示例：
[root@361way ~]# cat script.sh<br> #!/bin/bash<br> df -hl<br> ifconfig<br> ps auxf|grep snmp<br> [root@361way ~]# ansible 10.212.52.252 -m script -a 'scrip.sh'<br> 10.212.52.252 | FAILED => file or module does not exist: /root/scrip.sh<br> [root@361way ~]# ansible 10.212.52.252 -m script -a 'script.sh'<br> 10.212.52.252 | success >> {<br> "changed": true,<br> "rc": 0,<br> "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 "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"<br> }<br>
輸出結(jié)果很多，看起來也很亂，不過查下stdout部分，這個部分是實際上執(zhí)行后的結(jié)果。這里可以配合管道一起使用，可以如下使用：

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

篇幅所限，本來想把常用模塊都放在該篇來寫，感覺太冗長，后面再單獨分開相應的篇幅做模塊的介紹。

以上是介紹ansible的Ad-hoc與commands模組的詳細內(nèi)容。更多資訊請關(guān)注PHP中文網(wǎng)其他相關(guān)文章！