在 neimiko 中使用 TextFSM

在 neimiko 中使用 TextFSM

安装模板

$ cd ~
$ git clone https://github.com/networktocode/ntc-templates?__s=XXXXXXXX

查看安装完成

$ cd ~
$ ls ~/ntc-templates/templates/index

Netmiko已配置为自动在〜/ntc-template/templates/index中查找ntc-templates索引文件。另外，可以通过设置以下环境变量来明确告诉Netmiko在哪里寻找TextFSM模板目录（请注意，此目录中必须有一个索引文件）：
export NET_TEXTFSM=/path/to/ntc-templates/templates/

使用

查看ntc-templatesindex文件，确保其中有正确的命令且目录下存在模板文件。之后在 netmiko 中将use_textfsm = True参数添加到send_command()方法或send_command_timing()方法，即可获得结构化的数据；如果不存在模板，则正常返回字符串。

net_connect.send_command("show ip int brief", use_textfsm=True)

OUTPUT：

[{'intf': 'FastEthernet0',
  'ipaddr': 'unassigned',
  'status': 'down',
  'proto': 'down'},
 {'intf': 'FastEthernet1',
  'ipaddr': 'unassigned',
  'status': 'down',
  'proto': 'down'},
 {'intf': 'FastEthernet2',
  'ipaddr': 'unassigned',
  'status': 'down',
  'proto': 'down'},
 {'intf': 'FastEthernet3',
  'ipaddr': 'unassigned',
  'status': 'down',
  'proto': 'down'},
 {'intf': 'FastEthernet4',
  'ipaddr': '10.220.88.20',
  'status': 'up',
  'proto': 'up'}]

如何编写自定义TextFSM模板

示例

使用一系列正则表达式来定义要从纯文本输出中提取的数据。下面是一个处理思科接口的模板：

# cisco_asa_show_interface.template
Value Required INTERFACE (S+)
Value INTERFACE_ZONE (.+?)
Value LINK_STATUS (w+)
Value PROTOCOL_STATUS (.*)
Value HARDWARE_TYPE ([w ]+)
Value BANDWIDTH (d+s+w+)
Value DELAY (d+s+w+)
Value DUPLEX (w+-w+)
Value SPEED (d+w+sw+)
Value DESCRIPTION (.*)
Value ADDRESS ([a-zA-Z0-9]+.[a-zA-Z0-9]+.[a-zA-Z0-9]+)
Value MTU (d+)
Value IP_ADDRESS (d+.d+.d+.d+)
Value NET_MASK (d+.d+.d+.d+)
Value ONEMIN_IN_PPS (d+)
Value ONEMIN_IN_RATE (d+)
Value ONEMIN_OUT_PPS (d+)
Value ONEMIN_OUT_RATE (d+)
Value ONEMIN_DROP_RATE (d+)
Value FIVEMIN_IN_PPS (d+)
Value FIVEMIN_IN_RATE (d+)
Value FIVEMIN_OUT_PPS (d+)
Value FIVEMIN_OUT_RATE (d+)
Value FIVEMIN_DROP_RATE (d+)

Start
  ^.*Interface ${INTERFACE} "${INTERFACE_ZONE}", is ${LINK_STATUS}.*protocol is ${PROTOCOL_STATUS}
  ^s+Hardware is ${HARDWARE_TYPE} -> Continue
  ^.*BW ${BANDWIDTH}.*DLY ${DELAY}
  ^.*(${DUPLEX}.*Auto-Speed(${SPEED})
  ^.*Description: ${DESCRIPTION}
  ^.*MAC address ${ADDRESS}.*MTU ${MTU}
  ^.*IP address ${IP_ADDRESS}, .*subnet mask ${NET_MASK}
  ^.*1 minute input rate ${ONEMIN_IN_PPS} pkts/sec,s+${ONEMIN_IN_RATE} bytes/sec
  ^.*1 minute output rate ${ONEMIN_OUT_PPS} pkts/sec,s+${ONEMIN_OUT_RATE} bytes/sec
  ^.*1 minute drop rate, ${ONEMIN_DROP_RATE}
  ^.*5 minute input rate ${FIVEMIN_IN_PPS} pkts/sec,s+${FIVEMIN_IN_RATE} bytes/sec
  ^.*5 minute output rate ${FIVEMIN_OUT_PPS} pkts/sec,s+${FIVEMIN_OUT_RATE} bytes/sec
  ^.*5 minute drop rate, ${FIVEMIN_DROP_RATE} -> Record

通过show interface获取到的原始文本字符串：

# output of show interface
interfaces = '''
Interface GigabitEthernet0/0 "inside", is up, line protocol is up
  Hardware is i82540EM rev02, BW 1000 Mbps, DLY 10 usec
    Auto-Duplex(Full-duplex), Auto-Speed(1000 Mbps)
    Input flow control is unsupported, output flow control is off
    MAC address 0800.2735.03c6, MTU 1500
    IP address 169.254.1.11, subnet mask 255.255.255.0
    0 packets input, 0 bytes, 0 no buffer
    Received 0 broadcasts, 0 runts, 0 giants
    0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
    0 pause input, 0 resume input
    0 L2 decode drops
    1 packets output, 60 bytes, 0 underruns
    0 pause output, 0 resume output
    0 output errors, 0 collisions, 1 interface resets
    0 late collisions, 0 deferred
    0 input reset drops, 0 output reset drops
    input queue (blocks free curr/low): hardware (511/511)
    output queue (blocks free curr/low): hardware (511/510)
  Traffic Statistics for "inside":
    0 packets input, 0 bytes
    1 packets output, 28 bytes
    0 packets dropped
      1 minute input rate 0 pkts/sec,  0 bytes/sec
      1 minute output rate 0 pkts/sec,  0 bytes/sec
      1 minute drop rate, 0 pkts/sec
      5 minute input rate 0 pkts/sec,  0 bytes/sec
      5 minute output rate 0 pkts/sec,  0 bytes/sec
      5 minute drop rate, 0 pkts/sec

通过 TextFsm 进行处理：

# import library
import textfsm

# open the template file
with open('cisco_asa_show_interface.template', 'r') as f:
    template = textfsm.TextFSM(f)

# run the interface data through the template parser
template.ParseText(interfaces)

输出如下：

[['GigabitEthernet0/0',
  'inside',
  'up',
  'up',
  'i82540EM rev02',
  '1000 Mbps',
  '10 usec',
  'Full-duplex',
  '1000 Mbps',
  '',
  '0800.2735.03c6',
  '1500',
  '169.254.1.11',
  '255.255.255.0',
  '0',
  '0',
  '0',
  '0',
  '0',
  '0',
  '0',
  '0',
  '0',
  '0']]