今天介紹獲取本機網路流量並將其儲存的Python程式.
網路流量一向是系統人員關心的數據,市面上也有許許多多工具,
可以獲得以及繪圖,若自己也能開發此種程式,繪製符合自己需求
的圖形,對系統管理有莫大助益.

首先是建立RRD File的程式.

#!/usr/bin/env python
# ---------------------------------
# Python RRDTool
# Create Network RRD
# ---------------------------------

import rrdtool

rrdtool.create(
    'net.rrd', '--step', '60',
    'DS:net0_bytes_in:COUNTER:120:0:U',
    'DS:net0_packs_in:COUNTER:120:0:U',
    'DS:net0_error_in:COUNTER:120:0:U',
    'DS:net0_bytes_out:COUNTER:120:0:U',
    'DS:net0_packs_out:COUNTER:120:0:U',
    'DS:net0_error_out:COUNTER:120:0:U',
    'RRA:AVERAGE:0.5:1:2880',
    'RRA:AVERAGE:0.5:30:672',
    'RRA:AVERAGE:0.5:60:744',
    'RRA:AVERAGE:0.5:720:732',
    'RRA:MAX:0.5:1:2880',
    'RRA:MAX:0.5:30:672',
    'RRA:MAX:0.5:60:744',
    'RRA:MAX:0.5:720:732',
    'RRA:MIN:0.5:1:2880',
    'RRA:MIN:0.5:30:672',
    'RRA:MIN:0.5:60:744',
    'RRA:MIN:0.5:720:732',
    'RRA:LAST:0.5:1:2880',
    'RRA:LAST:0.5:30:672',
    'RRA:LAST:0.5:60:744',
    'RRA:LAST:0.5:720:732')

執行以後會建立 rrd 檔.
再來就是獲取本機網路流量的程式.

#!/usr/bin/env python
# -----------------------
# Python RRDTool
# Update Network RRD
# -----------------------

import rrdtool
import time

def get_net0():
    """get net0 data """
    net0_dict = {}
    item_list = ('rx_bytes', 'rx_packets', 'rx_errors',
                 'tx_bytes', 'tx_packets', 'tx_errors')
    with open('/proc/net/dev', 'r') as nets:
        nets_data = nets.readlines()
        net0_data = nets_data[-1]
        net0_list = net0_data.split()
        inet_name = net0_list[0]
        inet_name = inet_name.split(':')[0]
        rx_bytes = int(net0_list[1])
        rx_packets = int(net0_list[2])
        rx_errors = int(net0_list[3])
        tx_bytes = int(net0_list[9])
        tx_packets = int(net0_list[10])
        tx_errors = int(net0_list[11])
        net0_dict = dict(zip(item_list,
                    (rx_bytes, rx_packets, rx_errors,
                    tx_bytes, tx_packets, tx_errors)))
        return net0_dict
#
def update_net_rrd(rrdfile):
    """ Update net rrd file"""
    net_dict = get_net0()
    rx_bytes = net_dict['rx_bytes']
    rx_packets = net_dict['rx_packets']
    rx_errors = net_dict['rx_errors']
    tx_bytes = net_dict['tx_bytes']
    tx_packets = net_dict['tx_packets']
    tx_errors = net_dict['tx_errors']
    rrdtool.update(rrdfile, 'N:' + `rx_bytes` + ':' + `rx_packets` \
            + ':' + `rx_errors` + ':' + `tx_bytes` + ':' \
            + `tx_packets` + ':' + `tx_errors`)
#
if __name__ == '__main__':
    while 1:
        update_net_rrd('net.rrd')
        time.sleep(60)

放到背景執行,會每分鐘更新資料,接著讓子彈飛~~~
明天再來繪圖.