PySNMP 是一个纯粹用Python实现的SNMP,用PySNMP的最抽象的API为One-line Applications,其中有两类API：同步的和非同步的,都在模块pysnmp.entity.rfc3413.oneliner.cmdgen 中实现,如下是Get方式与Walk方式的基本实现.

首先需要在系统中安装SNMP客户端,对于Linux平台来说只需要执行如下配置过程即可.

[root@localhost ~]# yum install -y net-snmp[root@localhost ~]# cat /etc/snmp/snmpd.conf |grep -vE "^#|^$"com2sec notConfigUser  default       publicgroup   notConfigGroup v1           notConfigUsergroup   notConfigGroup v2c           notConfigUserview    systemview    included   .1view    systemview    included   .1access  notConfigGroup  ""  any  noauth  exact  systemview none none[root@localhost ~]# systemctl restart snmpd[root@localhost ~]# systemctl enable snmpd

如果是Windows系统则需要在客户机服务列表，开启SNMP支持，并设置好一个团体名称，如下图。

当我们配置好客户端后，服务端就客户获取数据了，我们以一个OID序号为例，我们查询特定序号对应的名称，然后将其记录下来，例如下面这样。

C:\Users\admin> snmpwalk -v 2c -c public 192.168.1.101 .1.3.6.1.2.1.25.2.2HOST-RESOURCES-MIB::hrMemorySize.0 = INTEGER: 2096632 KBytes

首先我们不使用PySNMP模块直接开线程调用看看,该代码如下所示.

import os,re,time# 通过SNMP收集主机CPU利用率: 通过SNMP协议,收集目标主机的CPU利用率(百分比),并返回JSON字符串.def Get_CPU_Info(addr):    try:        Head = ["HostName","CoreLoad","CpuUser","CpuSystem","CpuIdle"]        CPU = []        ret = os.popen("snmpwalk -v 2c -c nmap " + addr + " .1.3.6.1.2.1.1.5")        CPU.append(ret.read().split(":")[3].strip())        ret = os.popen("snmpwalk -v 2c -c nmap " + addr + " .1.3.6.1.2.1.25.3.3.1.2")        CPU.append(ret.read().split(":")[3].strip())        for i in [9,10,11]:            ret = os.popen("snmpwalk -v 2c -c nmap " + addr + " 1.3.6.1.4.1.2021.11.{}.0".format(i))            ret = ret.read()            Info = ret.split(":")[3].strip()            CPU.append(Info)        return dict(zip(Head,CPU))    except Exception:        return 0# 通过SNMP获取系统CPU负载信息: 分别获取到系统的1,5,15分钟的负载信息,并返回JSON格式.def Get_Load_Info(addr):    try:        Head = ["HostName","Load1","Load5","Load15"]        SysLoad = []        ret = os.popen("snmpwalk -v 2c -c nmap " + addr + " .1.3.6.1.2.1.1.5")        SysLoad.append(ret.read().split(":")[3].strip())        ret = os.popen("snmpwalk -v 2c -c nmap " + addr + " .1.3.6.1.4.1.2021.10.1.3")        load = list(re.sub(".*STRING: ", "", ret.read()).split("\n"))        SysLoad.append(load[0])        SysLoad.append(load[1])        SysLoad.append(load[2])        return dict(zip(Head,SysLoad))    except Exception:        return 0# 通过SNMP获取系统内存占用: 内存利用率，获取到之后，将其转化为字典格式保存。def Get_Mem_Info(addr):    try:        Head = ["HostName","memTotalSwap","memAvailSwap","memTotalReal","memTotalFree"]        SysMem = []        ret = os.popen("snmpwalk -v 2c -c nmap " + addr + " .1.3.6.1.2.1.1.5")        SysMem.append(ret.read().split(":")[3].strip())        ret = os.popen("snmpwalk -v 2c -c nmap " + addr + " .1.3.6.1.4.1.2021.4")        mem = ret.read().split("\n")        for i in [2,3,4,6]:            SysMem.append(re.sub(".*INTEGER: ","",mem[i]).split(" ")[0])        return dict(zip(Head,SysMem))    except Exception:        return 0# 通过SNMP获取系统磁盘数据: 这个案例并不完整,我只写了一点,后面有个问题一直没有解决.def Get_Disk_Info(addr):    try:        dic = {}        list = []        ret = os.popen("snmpwalk -v 2c -c nmap " + addr + " HOST-RESOURCES-MIB::hrStorageDescr")        DiskName = ret.read().split("\n")        ret =os.popen("snmpwalk -v 2c -c nmap " + addr + " HOST-RESOURCES-MIB::hrStorageUsed")        DiskUsed = ret.read().split("\n")        ret = os.popen("snmpwalk -v 2c -c nmap " + addr + " HOST-RESOURCES-MIB::hrStorageSize")        DiskSize = ret.read().split("\n")        for i in range(1,len(DiskName) - 7):            dic["Name"]= DiskName[i + 5].split(":")[3]            dic["Used"]= DiskUsed[i + 5].split(":")[3]            dic["Size"]= DiskSize[i + 5].split(":")[3]            list.append(dic)        return list    except Exception:        return 0if __name__ == '__main__':    for i in range(100):        dic = Get_CPU_Info("192.168.1.20")        print(dic)        time.sleep(1)

我们使用pysnmp模块来做，安装pysnmp很简单，执行命令pip install pysnmp 即可，安装后使用以下代码执行即可获取到目标数据，获取方式分为两种一种为Get另一种为Walk.

from pysnmp.hlapi import *import os,sysclass NetSNMP():    def __init__(self,address,region):        self.region = region        self.address = address    # 获取指定数据的方法    def GetNumber(self,oid,sub_oid,sub_id):        iterator = getCmd(SnmpEngine(),                          CommunityData(self.region),                          UdpTransportTarget((self.address, 161)),                          ContextData(),                          ObjectType(ObjectIdentity(oid, sub_oid, sub_id)))        errorIndication, errorStatus, errorIndex, varBinds = next(iterator)        if errorIndication:            return False        else:            if errorStatus:                return False            else:                for varBind in varBinds:                    return [x.prettyPrint() for x in varBind]    # 使用Walk拉取数据    def WalkNumber(self, oid):        res = []        for (errorIndication, errorStatus, errorIndex, varBinds) in nextCmd(SnmpEngine(),             CommunityData(self.region),UdpTransportTarget((self.address, 161)),ContextData(),             ObjectType(ObjectIdentity(oid)).addMibSource(             './site-packages/pysnmp/smi/mibs','pysnmp_mibs'),lexicographicMode=False):            if errorIndication:                print(errorIndication, file=sys.stderr)                break            elif errorStatus:                print('%s at %s' % (errorStatus.prettyPrint(),                                    errorIndex and varBinds[int(errorIndex) - 1][0] or '?'),                      file=sys.stderr)                break            else:                for varBind in varBinds:                    res.append(str(varBind))        return resif __name__ == "__main__":    # 初始化    ptr = NetSNMP("192.168.81.130","public")    # 使用GET方式获取OID数据    ret = ptr.GetNumber("HOST-RESOURCES-MIB","hrMemorySize",0)    print("类型: {} --> 返回结果: {} --> 解析: {}".format(type(ret),ret,ret[1]))    # 使用Walk方式获取OID数据    ret = ptr.WalkNumber(".1.3.6.1.2.1.2.2.1.6")    for each in ret:        mac = each.split("=")[1]        if len(mac) > 1:            print("网卡接口: {}".format(mac))