随着cmdb上记录的增多，每次都需要修改ansible的hosts文件， 实属麻烦。此次通过动态获取inventory的方法，这样可以省去配置ansible服务端的hosts。
#!/usr/bin/env python
# coding:utf-8


import json
import sys
import requests
from collections import defaultdict

'''
Region = {
    1: 'pro_sh',
    2: 'pro_ali',
    3: 'dev_ofc',
    4: 'test_ofc',
	5: ...
}
'''

null = ''
VIRTUAL_MACHINE_API = "http://IP:PORT/virtual/getAllVirtualMachine"
machine_list = eval（requests.get(VIRTUAL_MACHINE_API).content)
group_dict, host_dict = defaultdict(list), {}

CONFIG = 
    3: {
        'ansible_ssh_user': 'root',
        'ansible_ssh_port': 22,
        'ansible_ssh_private_key_file': '/root/.ssh/id_rsa'
    },
    4: {
        'ansible_ssh_user': 'root',
        'ansible_ssh_port': 12622,
        'ansible_ssh_private_key_file': '/root/.ssh/test_rsa'
    },
    ...
}


def group():
    for machine in machine_list:
        if machine.get("group"):
            group_dict[machine.get("group")].append(machine.get('ip'))
    print json.dumps(group_dict, indent=4)


def host(ip):
    for machine in machine_list:
        if machine.get('group'):
            host_dict[machine.get('ip')] = dict(CONFIG.get(machine.get('regionId'), CONFIG.get(3)),
                                                **{'ansible_ssh_host': machine.get('ip')})

    print json.dumps(host_dict.get(ip), indent=4)


if len(sys.argv) == 2 and (sys.argv[1] == '--list'):
    group()
elif len(sys.argv) == 3 and (sys.argv[1] == '--host'):
    host(sys.argv[2])
else:
    print "Usage: %s --list or --host <hostname>" % sys.argv[0]
    sys.exit(1)
		```

#### 动态inventory脚本必须支如下两个命令行参数：

--host （用来列出主机的详细信息） --list （用来列出群组）


#### 执行结果

./ansible_host.py --list

{ "dev_php": [ "10.101.11.14", "10.101.11.15", "10.101.11.16", "10.101.11.17" ], "dev_java": [ "10.101.9.101", "10.101.9.102", ... ], ... }

./ansible_host.py --host 10.101.11.14

{ "ansible_ssh_host": "10.101.11.14", "ansible_ssh_port": 22, "ansible_ssh_private_key_file": "/root/.ssh/id_rsa", "ansible_ssh_user": "root" }

#### 通过ansible命令调用

ansible -i ansible_hosts.py dev_php -m shell -a "ip a"

#### 通过playbook来调用，脱离了对于hosts文件的依赖

ansible-playbook -i ansible_hosts.py test.yml -e "host=dev_php"

PLAY [dev_php] ***************************************************************************************************************************************************************************************

TASK [Gathering Facts] ******************************************************************************************************************************************************************************* ok: [10.101.11.14] ok: [10.101.11.17] ok: [10.101.11.16] ok: [10.101.11.15]

TASK [echo] ****************************************************************************************************************************************************************************************** changed: [10.101.11.14] changed: [10.101.11.15] changed: [10.101.11.16] changed: [10.101.11.17]

PLAY RECAP ******************************************************************************************************************************************************************************************* 10.101.11.14 : ok=2 changed=1 unreachable=0 failed=0
10.101.11.15 : ok=2 changed=1 unreachable=0 failed=0
10.101.11.16 : ok=2 changed=1 unreachable=0 failed=0
10.101.11.17 : ok=2 changed=1 unreachable=0 failed=0