使用Squid部署代理缓存服务
Squid是Linux系统中最为流行的一款高性能代理服务软件,通常作为Web网站的前置缓存服务,能够代替用户向网站服务器请求页面数据并进行缓存.Squid服务配置简单、效率高、更能丰富，可以基于多种条件禁止用户访问存在威胁或不适宜的网站资源,因此可以保护企业内网的安全,提升用户的网络体验,帮助节省网络带宽.
配置Squid服务程序
首先准备两台虚拟机,一台用做Squid服务器,一台用作Squid客户端.
| 主机 | 操作系统 | IP地址 |
|---|---|---|
| Squid服务器 | RHEL7 | 172.16.10.20 |
| Squid客户端 | CentOS7 | 172.16.10.10 |
[root@Squid-Server ~]# ping www.baidu.com
PING www.a.shifen.com (61.135.169.121) 56(84) bytes of data.
64 bytes from 61.135.169.121 (61.135.169.121): icmp_seq=1 ttl=128 time=38.0 ms
64 bytes from 61.135.169.121 (61.135.169.121): icmp_seq=2 ttl=128 time=37.9 ms
//安装Squid服务
[root@Squid-Server ~]# yum install squid
Loaded plugins: product-id, search-disabled-repos, subscription-manager
This system is not registered with an entitlement server. You can use subscription-manager to register.
dvd | 4.1 kB 00:00:00
Resolving Dependencies
--> Running transaction check
---> Package squid.x86_64 7:3.5.20-10.el7 will be installed
--> Processing Dependency: perl(DBI) for package: 7:squid-3.5.20-10.el7.x86_64
--> Processing Dependency: perl(Digest::MD5) for package: 7:squid-3.5.20-10.el7.x86_64
--> Processing Dependency: squid-migration-script for package: 7:squid-3.5.20-10.el7.x86_64
--> Processing Dependency: libecap.so.3()(64bit) for package: 7:squid-3.5.20-10.el7.x86_64
--> Running transaction check
---> Package libecap.x86_64 0:1.0.0-1.el7 will be installed
---> Package perl-DBI.x86_64 0:1.627-4.el7 will be installed
--> Processing Dependency: perl(RPC::PlClient) >= 0.2000 for package: perl-DBI-1.627-4.el7.x86_64
--> Processing Dependency: perl(RPC::PlServer) >= 0.2001 for package: perl-DBI-1.627-4.el7.x86_64
---> Package perl-Digest-MD5.x86_64 0:2.52-3.el7 will be installed
--> Processing Dependency: perl(Digest::base) >= 1.00 for package: perl-Digest-MD5-2.52-3.el7.x86_64
---> Package squid-migration-script.x86_64 7:3.5.20-10.el7 will be installed
--> Running transaction check
---> Package perl-Digest.noarch 0:1.17-245.el7 will be installed
---> Package perl-PlRPC.noarch 0:0.2020-14.el7 will be installed
--> Processing Dependency: perl(Net::Daemon) >= 0.13 for package: perl-PlRPC-0.2020-14.el7.noarch
--> Processing Dependency: perl(Compress::Zlib) for package: perl-PlRPC-0.2020-14.el7.noarch
--> Processing Dependency: perl(Net::Daemon::Log) for package: perl-PlRPC-0.2020-14.el7.noarch
--> Processing Dependency: perl(Net::Daemon::Test) for package: perl-PlRPC-0.2020-14.el7.noarch
--> Running transaction check
---> Package perl-IO-Compress.noarch 0:2.061-2.el7 will be installed
--> Processing Dependency: perl(Compress::Raw::Bzip2) >= 2.061 for package: perl-IO-Compress-2.061-2.el7.noarch
--> Processing Dependency: perl(Compress::Raw::Zlib) >= 2.061 for package: perl-IO-Compress-2.061-2.el7.noarch
---> Package perl-Net-Daemon.noarch 0:0.48-5.el7 will be installed
--> Running transaction check
---> Package perl-Compress-Raw-Bzip2.x86_64 0:2.061-3.el7 will be installed
---> Package perl-Compress-Raw-Zlib.x86_64 1:2.061-4.el7 will be installed
--> Finished Dependency Resolution
Dependencies Resolved
==========================================================================================
Package Arch Version Repository Size
==========================================================================================
Installing:
squid x86_64 7:3.5.20-10.el7 dvd 3.1 M
Installing for dependencies:
libecap x86_64 1.0.0-1.el7 dvd 21 k
perl-Compress-Raw-Bzip2 x86_64 2.061-3.el7 dvd 32 k
perl-Compress-Raw-Zlib x86_64 1:2.061-4.el7 dvd 57 k
perl-DBI x86_64 1.627-4.el7 dvd 802 k
perl-Digest noarch 1.17-245.el7 dvd 23 k
perl-Digest-MD5 x86_64 2.52-3.el7 dvd 30 k
perl-IO-Compress noarch 2.061-2.el7 dvd 260 k
perl-Net-Daemon noarch 0.48-5.el7 dvd 51 k
perl-PlRPC noarch 0.2020-14.el7 dvd 36 k
squid-migration-script x86_64 7:3.5.20-10.el7 dvd 48 k
Transaction Summary
==========================================================================================
Install 1 Package (+10 Dependent packages)
Total download size: 4.4 M
Installed size: 14 M
Is this ok [y/d/N]: y
Downloading packages:
------------------------------------------------------------------------------------------
Total 10 MB/s | 4.4 MB 00:00:00
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Installing : perl-Compress-Raw-Bzip2-2.061-3.el7.x86_64 1/11
Installing : perl-Digest-1.17-245.el7.noarch 2/11
Installing : perl-Digest-MD5-2.52-3.el7.x86_64 3/11
Installing : 1:perl-Compress-Raw-Zlib-2.061-4.el7.x86_64 4/11
Installing : perl-IO-Compress-2.061-2.el7.noarch 5/11
Installing : libecap-1.0.0-1.el7.x86_64 6/11
Installing : 7:squid-migration-script-3.5.20-10.el7.x86_64 7/11
Installing : perl-Net-Daemon-0.48-5.el7.noarch 8/11
Installing : perl-PlRPC-0.2020-14.el7.noarch 9/11
Installing : perl-DBI-1.627-4.el7.x86_64 10/11
Installing : 7:squid-3.5.20-10.el7.x86_64 11/11
Verifying : perl-Net-Daemon-0.48-5.el7.noarch 1/11
Verifying : 7:squid-migration-script-3.5.20-10.el7.x86_64 2/11
Verifying : perl-Digest-MD5-2.52-3.el7.x86_64 3/11
Verifying : libecap-1.0.0-1.el7.x86_64 4/11
Verifying : perl-IO-Compress-2.061-2.el7.noarch 5/11
Verifying : 1:perl-Compress-Raw-Zlib-2.061-4.el7.x86_64 6/11
Verifying : perl-Digest-1.17-245.el7.noarch 7/11
Verifying : perl-DBI-1.627-4.el7.x86_64 8/11
Verifying : perl-Compress-Raw-Bzip2-2.061-3.el7.x86_64 9/11
Verifying : perl-PlRPC-0.2020-14.el7.noarch 10/11
Verifying : 7:squid-3.5.20-10.el7.x86_64 11/11
Installed:
squid.x86_64 7:3.5.20-10.el7
Dependency Installed:
libecap.x86_64 0:1.0.0-1.el7
perl-Compress-Raw-Bzip2.x86_64 0:2.061-3.el7
perl-Compress-Raw-Zlib.x86_64 1:2.061-4.el7
perl-DBI.x86_64 0:1.627-4.el7
perl-Digest.noarch 0:1.17-245.el7
perl-Digest-MD5.x86_64 0:2.52-3.el7
perl-IO-Compress.noarch 0:2.061-2.el7
perl-Net-Daemon.noarch 0:0.48-5.el7
perl-PlRPC.noarch 0:0.2020-14.el7
squid-migration-script.x86_64 7:3.5.20-10.el7
Complete!
| 参数 | 作用 |
|---|---|
| http_port 3128 | 监听的端口号 |
| cache_mem 64M | 内存缓冲区的大小 |
| cache_dir ufs /var/spool/squid 2000 16 256 | 硬盘缓冲区的大小 |
| cache_effective_user squid | 设置缓存的有效用户 |
| cache_effective_group squid | 设置缓存的有效用户组 |
| dns_nameservers [IP地址] | 一般不设置,而是用服务器默认的DNS地址 |
| cache_access_log /var/log/squid/access.log | 访问日志文件的保存路径 |
| cache_log /var/log/squid/cache.log | 缓存日志文件的保存路径 |
| visible_hostname [Name] | 设置Squid服务器的名称 |
标准正向代理
//启动服务加入开机启动项
[root@Squid-Server ~]# systemctl restart squid
[root@Squid-Server ~]# systemctl enable squid
Created symlink from /etc/systemd/system/multi-user.target.wants/squid.service to /usr/lib/systemd/system/squid.service.
52 http_access allow localnet
53 http_access allow localhost
54
55 # And finally deny all other access to this proxy
56 http_access deny all
57
58 # Squid normally listens to port 3128
59 http_port 3128
如果你开启了防火墙和Selinux又更改了默认端口号需要对端口进行放行
//查看
semanage port -l | grep squid_port_t
//添加新的端口号
semanage port -a -t squid_port_t -p tcp 10000
//再次查看
semanage port -l | grep squid_port_t
实验1: 只允许IP地址为172.16.10.10的客户端使用服务器上的Squid服务程序提供的代理服务,禁止其余所有主机代理请求
#################################################################
27 acl client src 172.16.10.10
28 #################################################################
29 #
30 # Recommended minimum Access Permission configuration:
31 #
32 # Deny requests to certain unsafe ports
33 #################################################################
34 http_access allow client
35 http_access deny all
36 #################################################################
37 http_access deny !Safe_ports
更改客户端的IP地址,再次尝试联网发现无法上网了,代理服务器拒绝连接.
实验2: 禁止所有客户端访问网址中包含linux关键词的网站.
#################################################################
27 #acl client src 172.16.10.10
28 acl deny_keyword url_regex -i linux
29 #################################################################
30 #
31 # Recommended minimum Access Permission configuration:
32 #
33 # Deny requests to certain unsafe ports
34 #################################################################
35 #http_access allow client
36 http_access deny deny_keyword
37 #http_access deny all
访问含有linux关键字的网址时被拒绝.
实验3: 禁止所有客户端访问某个特定的网站
#################################################################
27 #acl client src 172.16.10.10
28 #acl deny_keyword url_regex -i linux
29 acl deny_url url_regex http://www.linuxidc.com
30 #################################################################
31 #
32 # Recommended minimum Access Permission configuration:
33 #
34 # Deny requests to certain unsafe ports
35 #################################################################
36 #http_access allow client
37 #http_access deny deny_keyword
38 http_access deny deny_url
39 #http_access deny all
40 #################################################################
41 http_access deny !Safe_ports
42
43 # Deny CONNECT to other than secure SSL ports
44 http_access deny CONNECT !SSL_ports
访问指定网址被拒绝.访问其他网址正常访问.
实验4: 禁止员工在企业网内部下载带有某些后缀的文件
#################################################################
#acl client src 172.16.10.10
#acl deny_keyword url_regex -i linux
#acl deny_url url_regex http://www.linuxidc.com
acl badfile urlpath_regex -i .rar$ .avi$
#################################################################
#
# Recommended minimum Access Permission configuration:
#
# Deny requests to certain unsafe ports
#################################################################
#http_access allow client
#http_access deny deny_keyword
#http_access deny deny_url
#http_access deny all
http_access deny badfile
#################################################################
http_access deny !Safe_ports
透明正向代理
//客户端取消代理,网关指向squid服务器地址
[root@Squid-Server ~]# echo "net.ipv4.ip_forward=1" >> /etc/sysctl.conf
[root@Squid-Server ~]# sysctl -p
net.ipv4.ip_forward = 1
[root@Squid-Server ~]# iptables -t nat -A POSTROUTING -p udp --dport 53 -o ens35 -j MASQUERADE
此处网卡为对外的网卡
72 http_port 3128 transparent
73
74 # Uncomment and adjust the following to add a disk cache directory.
75 cache_dir ufs /var/spool/squid 100 16 256
[root@Squid-Server ~]# squid -k parse
[root@Squid-Server ~]# squid -z
2018/08/23 10:39:30| Squid is already running! Process ID 2299
[root@Squid-Server ~]# iptables -t nat -A PREROUTING -p tcp -m tcp --dport 80 -j REDIRECT --to-port 3128
[root@Squid-Server ~]# iptables -t nat -A POSTROUTING -s 172.16.10.0/24 -o ens35 -j SNAT --to 192.168.56.15
//此处网卡为对外的网卡
[root@Squid-Server ~]# service iptables save
反向代理
//主机设为NAT或者DHCP模式,配置文件编辑如下
http_port 192.168.56.15:80 vhost
cache_peer 39.104.16.126 parent 80 0 originserver
当你访问本机IP时访问的却是目标站点