ch01系统基础信息模块详解

ch01系统基础信息模块详解
第1章系统基础信息模块详解
1.1 系统性能信息模块 psutil
解决VMWare在Windows10的安装问题: 安装VC Redistributable 2017
解决虚拟机的上⽹问题：修改VMWare 的⽹络设置
解决PuTTY连接不上虚拟机的问题：修改VMnet8的IPv4地址
在Centos7安装pip
在Centos7安装psutil模块
#1、以root⾝份登陆CentOS依次执⾏以下命令：
wget https:///packages/source/p/psutil/psutil-2.1.3.tar.gz --no-check-certificate
tar zxvf psutil-2.1.3.tar.gz
cd psutil-2.1.3/
python setup.py install
#2、在执⾏以上命令最后的安装命令时，遇到以下问题
psutil/_psutil_linux.c:12:20: fatal error: Python.h: No such file or directory
这样的错误提⽰,表⽰缺少Python-dev的依赖环境,直接安装Python-devel即可
yum -y install python-devel*
安装完后,再执⾏ python setup.py install 即可
安装完成提⽰:
Installed /usr/lib64/python2.7/site-packages/psutil-2.1.3-py2.7-linux-x86_64.egg
Processing dependencies for psutil==2.1.3
Finished processing dependencies for psutil==2.1.3
1.1.1 获取系统性能信息
(1) CPU信息
>>> import psutil
/usr/lib64/python2.7/site-packages/psutil-2.1.3-py2.7-linux-x86_64.egg/_psutil_linux.py:3: UserWarning: Module _psutil_linux was already imported from /usr/lib64/python2.7/site-packages/psutil-2.1.3-py2.7-linux-x86_64.egg/_psutil_linux.pyc, but >>> psutil.cpu_times()
scputimes(user=46.0, nice=0.27, system=87.6, idle=10040.74, iowait=52.76, irq=0.0, softirq=9.79, steal=0.0, guest=0.0, guest_nice=0.0)
>>> psutil.cpu_times().user
46.03
>>> psutil.cpu_count()
2
>>> psutil.cpu_count(logical=False)
2
>>>
(2)内存信息
>>> mem = psutil.virtual_memory()
>>> mem
svmem(total=1907970048L, available=1505476608L, percent=21.1, used=915431424L, free=992538624L, active=423669760, inactive=202493952, buffers=2134016L, cached=510803968)
>>> mem.total
1907970048L
>>> mem.free
992538624L
>>> psutil.swap_memory()
sswap(total=2147479552L, used=0L, free=2147479552L, percent=0.0, sin=0, sout=0)
>>>
(3)磁盘信息
>>> psutil.disk_partitions()
[sdiskpart(device='/dev/sda3', mountpoint='/', fstype='xfs', opts='rw,seclabel,relatime,attr2,inode64,noquota'), sdiskpart(device='/dev/sda1', mountpoint='/boot', fstype='xfs', opts='rw,seclabel,relatime,attr2,inode64,noquota')]
>>> psutil.disk_usage('/')
sdiskusage(total=19001245696, used=4522000384, free=14479245312, percent=23.8)
>>> psutil.disk_io_counters()
sdiskio(read_count=14186, write_count=8265, read_bytes=432613888, write_bytes=230467072, read_time=225143, write_time=59109)
>>> psutil.disk_io_counters(perdisk=True)
{'sr0': sdiskio(read_count=18, write_count=0, read_bytes=1052672, write_bytes=0, read_time=761, write_time=0), 'sda2': sdiskio(read_count=54, write_count=0, read_bytes=2527232, write_bytes=0, read_time=335, write_time=0), 'sda3': sdiskio(r >>>
(4)⽹络信息
>>> _io_counters()
snetio(bytes_sent=1227849, bytes_recv=34910887, packets_sent=12412, packets_recv=29882, errin=0, errout=0, dropin=0, dropout=0)
>>> _io_counters(pernic=True)
{'lo': snetio(bytes_sent=14274, bytes_recv=14274, packets_sent=144, packets_recv=144, errin=0, errout=0, dropin=0, dropout=0), 'ens33': snetio(bytes_sent=1216087, bytes_recv=34904091, packets_sent=12290, packets_recv=29824, errin=0, >>>
(5)其他系统信息
>>> ers()
[suser(name='root', terminal='tty1', host='', started=1597921920.0), suser(name='root', terminal='pts/0', host='192.168.135.1', started=1597933824.0), suser(name='chenjo', terminal='pts/1', host='192.168.135.1', started=1597923712.0)]
>>> import datetime
>>> psutil.boot_time()
1597925932.0
>>> datetime.datetime.fromtimestamp(psutil.boot_time()).strftime("%Y-%m-%d %H:%M:%S")
'2020-08-20 20:18:52'
>>>
1.1.2 系统进程管理⽅法
(1)进程信息
>>> import psutil
>>> psutil.pids()
[1, 2, 3, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 16, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 36, 37, 38, 39, 47, 48, 49, 50, 51, 53, 66, 97, 638, 649, 655, 664, 666, 805, 810, 1678, 1683, 1824, 1828, 2876, 2877, 2887, 2890, 2893, 2894, 2895, 2896, >>> p = psutil.Process(17557)
>>>
<bound method of <psutil.Process(pid=17557, name='python') at 139991911690768>>
>>> p.exe()
'/usr/bin/python2.7;5f3e6c2d'
>>> p.cwd()
'/tmp'
>>> p.status()
'stopped'
>>> p.create_time()
1597928634.08
>>> p.uids()
puids(real=0, effective=0, saved=0)
>>> p.gids()
pgids(real=0, effective=0, saved=0)
>>> p.cpu_times()
pcputimes(user=0.01, system=0.0)
>>> p.cpu_affinity()
[0, 1]
>>> p.memory_percent()
0.27350031021032045
>>> p.memory_info()
pmem(rss=5218304, vms=133287936)
>>> p.io_counters()
pio(read_count=118, write_count=9, read_bytes=0, write_bytes=0)
>>> p.connections()
[]
>>> p.num_threads()
1
>>>
(2)popen类的使⽤
import psutil
from subprocess import PIPE
p = psutil.Popen(["/usr/bin/python", "-c", "print('hello')"], stdout=PIPE)
()
ername()
p.cpu_times()
municate()
#p.cpu_times()
[root@ansible mycode]# python
Python 2.7.5 (default, Apr 2 2020, 13:16:51)
[GCC 4.8.5 20150623 (Red Hat 4.8.5-39)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import psutil
>>> from subprocess import PIPE
>>> p = psutil.Popen(["/usr/bin/python", "-c", "print('hello')"], stdout=PIPE)
>>> ()
'python'
>>> ername()
'root'
>>> p.cpu_times()
pcputimes(user=0.01, system=0.0)
>>> municate()
('hello\n', None)
>>>
参考提⽰
1.1.1节⽰例参考https:///giampaolo/psutil
1.1.1节模块说明参考官⽹/en/latest
1.2 实⽤的IP地址处理模块IPy
Centos7上安装ipy
>>> from IPy import IP
>>> IP('10.0.0.0/8').version()
4
>>> IP('::1').version()
6
>>>
>>> ip = IP('192.168.0.0/16')
>>> print ip.len()
65536
>>> for x in ip:
... print(x)
...
192.168.0.0
192.168.0.1
192.168.0.2
192.168.0.3
...
>>> print(IP('192.168.1.0').make_net('255.255.255.0'))
192.168.1.0/24
>>> print(IP('192.168.1.0/255.255.255.0', make_net=True))
192.168.1.0/24
>>> print(IP('192.168.1.0-192.168.1.255', make_net=True))
192.168.1.0/24
>>>
wantprefixlen 的取值及含义：
wantprefixlen = 0，⽆返回，如192.168.1.0。

wantprefixlen = 1，prefix格式，如192.168.1.0/24。

wantprefixlen = 2，decimalnetmask格式，如192.168.1.0/255.255.255.0。

wantprefixlen = 3，lastIP格式，如192.168.1.0-192.168.1.255。

>>> IP('192.168.1.0/24').strNormal(0)
'192.168.1.0'
>>> IP('192.168.1.0/24').strNormal(1)
'192.168.1.0/24'
>>> IP('192.168.1.0/24').strNormal(2)
'192.168.1.0/255.255.255.0'
>>> IP('192.168.1.0/24').strNormal(3)
'192.168.1.0-192.168.1.255'
>>>
1.2.2. 多⽹络计算⽅法详解
⽐较⼤⼩，是否包含
>>> from IPy import IP
>>> IP('10.0.0.0/24') < IP('12.0.0.0/24')
True
>>> '192.168.1.100' in IP('192.168.1.0/24')
True
>>> IP('192.168.1.0/24') in IP('192.168.0.0/16')
True
>>>
是否重叠
>>> IP('192.168.0.0/23').overlaps('192.168.1.0/24')
1
>>> IP('192.168.1.0/24').overlaps('192.168.2.0')
>>>
⽰例根据输⼊的IP或⼦⽹返回⽹络、掩码、⼴播、⽅向解析、⼦⽹数、IP类型等信息
[root@ansible ops_automation]# ./ch01_ipy
Please input an IP or net-range: 192.168.1.0/24
net: 192.168.1.0
netmask: 255.255.255.0
broadcast: 192.168.1.255
reverse address: 1.168.192.in-addr.arpa.
number of subnets: 256
hexadecimal: 0xc0a80100
binary ip: 11000000101010000000000100000000
iptype: PRIVATE
[root@ansible ops_automation]# ./ch01_ipy
Please input an IP or net-range: 192.168.1.20
reverse address: 20.1.168.192.in-addr.arpa.
hexadecimal: 0xc0a80114
binary ip: 11000000101010000000000100010100
iptype: PRIVATE
参考⽂献
1.3 DNS处理模块dnspython
安装
# wget /kits/1.9.4/dnspython-1.9.4.tar.gz
# tar -zxvf dnspython-1.9.4.tar.gz
# cd dnspython-1.9.4
# python setup.py install
1.3.1 模块域名解析⽅法详解
query⽅法的定义如下：
query(self, qname, rdtype=1, rdclass=1, tcp=False, source=None, raise_on_no_answer=True, source_port=0) qname参数是待查询的域名，rdtype参数是资源的类型，常⽤的有以下⼏种：
A记录，将主机名转换成IP地址
MX记录，邮件交换记录，定义邮件服务器的域名
CNAME记录，指别名记录，实现域名间的映射
NS记录，标记区域的域名服务器及授权⼦区域。

PTR记录，反向解析，与A记录相反，将IP转换成主机名。

SOA记录，SOA标记，⼀个起始授权区的定义
rdclass参数⽤于指定⽹络类型，可选值有IN、CH与HS，其中IN为默认。

tcp参数⽤于指定是否启⽤TCP协议，默认为False。

source与source_port参数指定查询源地址与端⼝，默认值为查询设备IP地址与0。

raise_on_no_answer参数⽤于指定当查询⽆应答时是否触发异常。

1.3.2 常见解析类型⽰例说明
（1）A记录
若dnspython模块报错 AttributeError: 'CNAME' object has no attribute 'address'，可
#!/usr/bin/env python
import dns.resolver
domain = raw_input('Please input a domain: ')
A = dns.resolver.query(domain, 'A')
for i in A.response.answer:
for j in i.items:
if j.rdtype == 1:
print(j.address)
（2）MX记录
#!/usr/bin/env python
import dns.resolver
domain = raw_input('Please input a domain: ')
MX = dns.resolver.query(domain, 'MX')
for i in MX:
print 'MX preference = ', i.preference, 'mail exchanger = ', i.exchange
以域名为例：
[root@ansible ch01]# ./dnspython_ex2.py
Please input a domain:
MX preference = 10 mail exchanger = .
MX preference = 10 mail exchanger = .
MX preference = 10 mail exchanger = .
MX preference = 50 mail exchanger = .
（3）NS记录
#!/usr/bin/env python
import dns.resolver
domain = raw_input('Please input a domain: ')
ns = dns.resolver.query(domain, 'NS')
for i in ns.response.answer:
for j in i.items:
print j.to_text()
只限输⼊⼀级域名，如。

如果输⼊⼆级或多级域名，如，则是错误的。

[root@ansible ch01]# ./dnspython_ex3.py
Please input a domain:
.
.
.
.
.
（4）CNAME记录
#!/usr/bin/env python
import dns.resolver
domain = raw_input('Please input a domain: ')
cname = dns.resolver.query(domain, 'CNAME')
for i in cname.response.answer:
for j in i.items:
print j.to_text()
结果将返回cname后的⽬标域名。

[root@ansible ch01]# ./dnspython_ex4.py
Please input a domain:
.
1.3.3 实践：DNS域名轮询业务监控
（1）步骤
1. 实现域名的解析，获取域名的所有的A记录，解析IP列表。

2. 对IP列表进⾏HTTP级别的探测。

（2）代码实现
#!/usr/bin/env python
# -*- coding: utf-8 -*-
import dns.resolver
import os
import httplib
iplist = [] # 定义域名IP列表变量
appdomain = "" # 定义业务域名
def get_iplist(domain=""): # 域名解析函数，解析成功IP将被追加到iplist
try:
A = dns.resolver.query(domain, 'A')
except Exception, e:
print "dns resolver error: " + str(e)
return
for i in A.response.answer:
for j in i.items:
if j.rdtype == 1:
iplist.append(j.address)
return True
def checkip(ip):
checkurl = ip + ":80"
getcontent=""
httplib.socket.setdefaulttimeout(5)
conn = httplib.HTTPConnection(checkurl)
try:
conn.request("GET", "/", headers = {"Host": appdomain})
r = conn.getresponse()
getcontent = r.read(15)
finally:
if getcontent == "<!DOCTYPE html>": # 监控URL页的内容⼀般是事先定义好的，⽐如 HTTP 200 等
print ip + " [OK]"
else:
print ip + " [Error]" # 此处可放告警程序，可以是邮件、短信通知
if __name__ == "__main__":
if get_iplist(appdomain) and len(iplist) > 0:
for ip in iplist:
checkip(ip)
else:
print "dns resolver error."
我们可以将此脚本放到crontab中定时运⾏，再结合告警程序，这样⼀个基于域名轮询的业务监控已经完成。

运⾏结果如下：[root@ansible ch01]# ./dnspython_ex5.py
14.215.177.39 [OK]
14.215.177.38 [OK]。