利用python实现自动捕获进程netstat信息和自动捕获telnet信息，保存log文件

*采用subprocess类，实现执行shell命令，捕获netstat、pstack、maps等进程重要数据，保存到log文件
*采用libtelnet库登录telnet
*捕获telnet输出到log文件

---

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
AUTH: [email protected]
tag: telnet ,then execute all of the API,and capture the print line writing to file;
    Local only
"""
import telnetlib
import subprocess
import re
import sys
import time
import socket
from sys import argv

exename = 'test'
filename = './testlogflush.log'
apilist = ['version', 'help']
arglist = argv[1:]  # 支持传参

def conscmd(): #要执行的系统shell命令
    '''
    :return: all the shell cmdline
    '''
    global cmdlist
    # 0 and 1 is inner cmd
    cmdlist.append('ps -aux| grep /{}| grep -v grep'.format(exename))
    cmdlist.append( 'netstat -pnlt| grep {}'.format(exename) )
    #following lines, is user define
    cmdlist.append('ps -aux| grep /{}'.format(exename))
    cmdlist.append( 'netstat -apn| grep {}'.format(exename) )
    cmdlist.append( 'df -h' )
    exepid = filtcmdline(cmdlist[0])
    if exepid:
        cmdlist.append( 'ps -o comm,lstart -p {}'.format(exepid) )
        cmdlist.append( 'top -bHp {} -n 3'.format(exepid) )
        cmdlist.append( 'pstack {}'.format(exepid) )
        cmdlist.append('cat /proc/{}/task/*/stat'.format(exepid))
        cmdlist.append('cat /proc/{}/maps'.format(exepid))
        cmdlist.append('cat /proc/{}/smaps'.format(exepid))


def getlocalhostip(): #获取本机ip
    '''
    get the local ip address
    :return:
    '''
    try:
        s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        s.connect(('8.8.8.8', 80))
        ip = s.getsockname()[0]
    except:
        print(sys._getframe().f_code.co_name, '() captured except ', sys.exc_info()[0], sys.exc_info()[1])
    finally:
        s.close()
    return ip

def execcmd(cmd):  #执行系统shell命令
    '''
    :param cmd: ssh cmd
    :return: the cmd result(bytes of list)
    '''
    try:
        proc = subprocess.Popen(cmd, shell=True, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
        time.sleep(0.1) # waited subprocess end
        if proc.poll() != None:
            print( "executed cmd: {0} .error= {2}, subprocess.Popen-poll() = {1}".format(cmd, proc.poll(), proc.stdout.readlines()) )
            proc.terminate()
            return None
        else:
            cmdline = proc.stdout.readlines() # list bytes
            print( "executed cmd: {0} .OK".format(cmd) )
            return cmdline
    except :
        print(sys._getframe().f_code.co_name, '() captured except ', sys.exc_info()[0], sys.exc_info()[1])
        raise
    return None

def filtcmdline(cmd, cmdtype='pid'):
    '''
    get the LISTEN port of telnet
    :param cmd:
    :param cmdtype: 'pid' or 'telnetport'
    :return: program's telnet port, named exename
    '''
    try:
        cmdret = execcmd(cmd )
        if cmdret:
            reline = ''
            if cmdtype == 'pid':
                reline = r'\b\d{3,7}\b'
            elif cmdtype == 'telnetport':
                reline = r'0.0.0.0:2\d\d\d\b'
            strret = re.search(reline, str(cmdret.pop(), encoding='utf-8'))
            if strret:
                return int( strret.group().split(":").pop() )
            else:
                print("re.match error")
        else:
            print("fun: {} execute execcmd() failed".format(sys._getframe().f_code.co_name))
    except :
        print(sys._getframe().f_code.co_name, '(), captured except ', sys.exc_info()[0], sys.exc_info()[1])
    return 0

def execapi(teln):  # 执行进程telnet中的api命令
    '''
    :param teln: the handle of telnet's connection
    :return:
    '''
    try:
        teln.read_until(b"Username:")
        teln.write(b'admin\r\n')
        teln.read_until(b"Password:")
        teln.write(b'admin\r\n')
        teln.write(b'\r\n' * 4)
        for cd in apilist:
            teln.write(bytes(cd,encoding = "utf8")+b'\r\n')
            time.sleep(0.5)
    except:
        print(sys._getframe().f_code.co_name, '(), captured except ', sys.exc_info()[0], sys.exc_info()[1])
        raise

def logtelnet(flog): #telnet到进程服务
    '''
    telnet to mcu
    :param flog: logfile's handle
    :return:
    '''
    mcuport = filtcmdline(cmdlist[1], 'telnetport')
    if mcuport:
        try:
            tn = telnetlib.Telnet('127.0.0.1', mcuport)
            execapi(tn)
            # print("logtelnet: {}".format(tn.read_very_eager().decode('gbk')))
            flog.write(tn.read_very_eager() + b'\r\n' * 3)
        except:
            print(sys._getframe().f_code.co_name, '(), captured except ', sys.exc_info()[0], sys.exc_info()[1])
        finally:
            tn.close()
    else:
        print("error telnetport: ",mcuport)
        return False
    return True

def  logcmddict(flog):
    '''
    capturing all cmd stdoutline
    :param flog: the logfile handle
    :return:
    '''
    localip = getlocalhostip()
    for v in cmdlist[2:]:
        time.sleep(0.5)
        cmdret = execcmd(v)
        if cmdret:   # print("cmdkey: {}".k))
            flog.write(bytes('[[email protected] {}]# '.format(localip)+ v, encoding='utf-8')+b'\n')
            for i in cmdret:
                flog.write(i)
            flog.write(b'\n' * 3)
        else:
            print('executed cmdline failed')

def writinglog():  # 写文件
    '''
    :return:
    '''
    with open(filename, 'wb') as fl:
        logtelnet(fl)
        logcmddict(fl)

cmdlist = []
if __name__ == "__main__":
    conscmd()
    writinglog()