编写Ansible模块并自定义Facts例子

时间：2015-01-23 来源：西部数据作者：西部数据

下面来看一个编写Ansible模块并自定义Facts例子,希望例子能帮助到各位.

背景介绍:Ansible自带的Facts有很多,但很多时候并不够用,比如,Ansible就没有ansible_private_ipv4_address这样一个Facts,用来保存私网IP地址.

而我们恰恰就需要这样的一个Facts,因为我们有很多服务器的默认网卡并非是eth0，有的是bond0,eth1,em0,em1等,而公网IP地址与私网IP地址也并没有固定的绑定在某个网卡上,很多时候还是虚拟网卡.

还好,我们可以通过编写Ansible模块并自定义Facts来实现,具体步骤,代码如下:

[root@idc-server2 ~]# ifconfig

eth0      Link encap:Ethernet  HWaddr 1B:2B:3B:4B:5B:6B

          inet addr:172.16.1.2  Bcast:172.16.1.255  Mask:255.255.252.0

...

eth1      Link encap:Ethernet  HWaddr 1A:2A:3A:4A:5A:6A

          inet addr:100.100.100.100  Bcast:100.100.100.255  Mask:255.255.255.240

...

lo        Link encap:Local Loopback

          inet addr:127.0.0.1  Mask:255.0.0.0

...

[root@idc-server1 ansible]# vim myfacts.yml

---

- hosts: idc-server2

  roles:

  - myfacts

[root@idc-server1 ansible]# mkdir -p roles/myfacts/{tasks,templates}

[root@idc-server1 ansible]# vim roles/myfacts/tasks/main.yml

---

- name: run myfacts module to get customized facts

  myfacts: get_facts=yes

- name: update file with the customized facts

  template: src=myfacts.txt.j2 dest=/tmp/myfacts.txt

[root@idc-server1 ansible]# vim roles/myfacts/templates/myfacts.txt.j2

ansible_private_ipv4_address : {{ ansible_private_ipv4_address }}

[root@idc-server1 ansible]# mkdir /usr/share/ansible/heylinux

[root@idc-server1 ansible]# vim /usr/share/ansible/heylinux/myfacts

#!/usr/bin/python

import sys

import json

import shlex

import commands

import re

def get_ansible_private_ipv4_address():

    iprex = "(^192.168)|(^10.)|(^172.1[6-9])|(^172.2[0-9])|(^172.3[0-1])"

    output = commands.getoutput("""/sbin/ifconfig |grep "Link encap" |awk '{print $1}' |grep -wv 'lo'""")

    nics = output.split('n')

    t_nic_info = ""

    for i in nics:

        ipaddr = commands.getoutput("""/sbin/ifconfig %s |grep -w "inet addr" |cut -d: -f2 | awk '{print $1}'""" % (i))

        if re.match(iprex,ipaddr):

            ansible_private_ipv4_address = ipaddr

    return ansible_private_ipv4_address

args_file = sys.argv[1]

args_data = file(args_file).read()

arguments = shlex.split(args_data)

for arg in arguments:

    if "=" in arg:

        (key, value) = arg.split("=")

        if key == "get_facts" and value == "yes":

            ansible_private_ipv4_address = get_ansible_private_ipv4_address()



            print json.dumps({

               "changed" : False,

               "ansible_facts" : {

                  "ansible_private_ipv4_address" : ansible_private_ipv4_address

               }

            })

            sys.exit(0)

print json.dumps({

    "changed" : False

})

[root@idc-server1 ansible]# ansible-playbook -u root myfacts.yml -i hosts

PLAY [idc1-server2] ***************************************************************

GATHERING FACTS ***************************************************************

ok: [idc1-server2]

TASK: [myfacts | run myfacts module to get customized facts] **************

ok: [idc1-server2]

TASK: [myfacts | update file with the customized facts] *********************

changed: [idc1-server2]

PLAY RECAP ********************************************************************

idc1-server2 : ok=3    changed=1    unreachable=0    failed=0   --phpfensi.com

[root@idc-server1 ansible]# ssh idc1-server2 'cat /tmp/myfacts.txt'

ansible_private_ipv4_address : 172.16.1.2