1、什么是squid
Squid cache(简称为Squid)是一个流行的自由软件(GNU通用公共许可证)的代理服务器和Web缓存服务器。Squid有广泛的用途,从作为网页服务器的前置cache服务器缓存相关请求来提高Web服务器的速度,到为一组人共享网络资源而缓存万维网,域名系统和其他网络搜索,到通过过滤流量帮助网络安全,到局域网通过代理上网。Squid主要设计用于在Unix一类系统运行。
Squid的发展历史相当悠久,功能也相当完善。除了HTTP外,对于FTP与HTTPS的支援也相当好,在3.0 测试版中也支援了IPv6。
squid可以做代理也可以做缓存;
squid缓存不仅可以节省宝贵的带宽资源,也可以大大降低服务器的I/O
squid不仅可以做正向代理,又可以做反向代理。
正向代理,squid后面是客户端,客户端上网要通过Squid去上;反向代理,squid后面是服务器,服务器返回给用户数据需要走squid。
正向代理用在企业的办公环境中,员工上网需要通过squid代理来上网,这样可以节省网络带宽资源。而反向代理用来搭建网站静态项(图片、html、流媒体、js、css等)的缓存服务器,它用于网站架构中。
2、搭建squid正向代理
官方网站为 http://www.squid-cache.org/
安装命令:yum install -y squid
squid -v 查看版本以及编译参数(Squid Cache: Version 3.1.10)
> /etc/squid/squid.conf 清空配置文件;
vim /etc/squid/squid.conf
加入如下配置:
http_port 3128
visible_hostname changjiangyun
acl manager proto cache_object
acllocalhost src 127.0.0.1/32 ::1
aclto_localhost dst 127.0.0.0/8 0.0.0.0/32 ::1
acllocalnet src 10.0.0.0/8 # RFC1918possible internal network
acllocalnet src 172.16.0.0/12 # RFC1918possible internal network
acllocalnet src 192.168.0.0/16 # RFC1918 possible internal network
aclSSL_ports port 443
aclSafe_ports port 80 8080
aclSafe_ports port 21
aclSafe_ports port 443
aclCONNECT method CONNECT
http_access allow manager localhost
http_access deny manager
http_access deny !Safe_ports
http_access deny CONNECT !SSL_ports
http_access allow localnet
http_access allow localhost
http_access allow all
cache_dir aufs /data/cache 1024 16 256
cache_mem 128 MB
hierarchy_stoplist cgi-bin ?
coredump_dir /var/spool/squid
refresh_pattern ^ftp: 1440 20% 10080
refresh_pattern ^gopher: 1440 0% 1440
refresh_pattern -i (/cgi-bin/|\?) 0 0% 0
refresh_pattern \.(jpg|png|gif|mp3|xml)1440 50% 2880 ignore-reload
refresh_pattern . 0 20% 4320
############################## 到此结束
配置解释:
acl Safe_ports port 80 8080 # http的端口
acl Safe_ports port 21 # ftp的端口
acl Safe_ports port 443 # https的端口
cache_dir aufs /data/cache 1024 16 256 #缓存空间1024M大小 16个一级目录,256个子目录
cache_mem 128 MB #缓存可以使用的内存大小;放在内存中访问数据速度快;
mkdir /data/cache #创建缓存目录
chown -R squid:squid /data/cache #更改缓存目录权限
squid -z #初始化缓存目录,squid新版本3.1可以省略
/etc/init.d/squid start #启动squid服务
squid -k check #可以检测配置文件是否有错;可以简写为-kche
squid -k rec #可以重新加载配置,reconfig的简写;
service squid restart #重启squid服务;重启经常性的很慢,可以先killall squid,在启动服务;
检测配置文件,报错:Could not determine this machines public hostname. Please configureone or set ‘visible_hostname‘.没有定义公共主机名,需要配置visible_hostname 可视化主机名;(squid出问题,会在浏览器显示squid的主机名)
在配置文件中加入:visible_hostname yonglinux 就不会报错;
[root@yonglinux ~]# squid -k check
2015/05/25 03:09:18| WARNING: Could notdetermine this machines public hostname. Please configure one or set‘visible_hostname‘.
2015/05/25 03:09:18| WARNING: Could notdetermine this machines public hostname. Please configure one or set‘visible_hostname‘.
squid: ERROR: No running copy
在另一台linux进行测试:curl -x192.168.22.30:3128 www.qq.com
指定代理服务器192.168.22.30的3128端口访问网站,前提保证代理服务器能访问网站;
设定代理服务器的作用是让局域网的用户访问网站速度快,另一方面可以控制用户访问哪些网站;上班期间禁止员工看视频,购物;
访问图片,测试缓存,缓存的时间,X-Cache为HIT击中,说明squid缓存起作用;第一次为MISS;
[root@localhost ~]# curl -x192.168.22.30:3128‘http://www.51cto.com/images/home/images/logo.jpg‘ -I
HTTP/1.0 200 OK
Server: Tengine
Date: Sun, 24 May 2015 13:42:43 GMT
Content-Type: image/jpeg
Content-Length: 5309
Last-Modified: Wed, 22 Jan 2014 07:55:12 GMT
Expires: Sun, 31 May 2015 13:42:43 GMT
Cache-Control: max-age=604800
Load-Balancing: web39
Accept-Ranges: bytes
Age:29661
X-Cache: HIT from yonglinux
X-Cache-Lookup: HIT from yonglinux:3128
Via:1.0 yonglinux (squid/3.1.10)
Connection: keep-alive
设置squid代理服务器只代理某几个域名
设置域名白名单,允许baidu sohu可以访问,其他都拒绝;
vim /etc/squid/squid.conf 下面的内容加入到squid配置文件acl下面;
acl http proto HTTP
acl good_domain dstdomain .baidu.com.sohu.com
http_access allow http good_domain
http_access deny http !good_domain
使用curl测试白名单,baidu、sohu返回状态码为200 OK,qq不在白名单则返回403;
[root@localhost ~]# curl -x192.168.22.30:3128www.sohu.com -I
HTTP/1.0 200 OK
Content-Type: text/html
Date: Sun, 24 May 2015 13:57:32 GMT
Server: SWS
Vary: Accept-Encoding
Cache-Control: no-transform, max-age=120
Expires: Sun, 24 May 2015 13:59:32 GMT
Last-Modified: Sun, 24 May 2015 13:57:21 GMT
X-RS: 11172604.20347654.12509576
FSS-Cache: HIT from 9861864.17726194.11198816
X-Cache: MISS from yonglinux
X-Cache-Lookup: MISS from yonglinux:3128
Via:1.0 yonglinux (squid/3.1.10)
Connection: keep-alive
[root@localhost ~]# curl -x192.168.22.30:3128www.qq.com -I
HTTP/1.0 403 Forbidden
Server: squid/3.1.10
Mime-Version: 1.0
Date: Sun, 24 May 2015 22:04:30 GMT
Content-Type: text/html
Content-Length: 3254
X-Squid-Error: ERR_ACCESS_DENIED 0
Vary: Accept-Language
Content-Language: en
X-Cache: MISS from yonglinux
X-Cache-Lookup: NONE from yonglinux:3128
Via:1.0 yonglinux (squid/3.1.10)
Connection: keep-alive
限制某些域名不能通过代理访问
设置域名黑名单,不允许访问taobao.com jd.com;其他的都允许;
vim /etc/squid/squid.conf 下面的内容加入到squid配置文件acl下面
acl http proto HTTP
acl bad_domain dstdomain .taobao.com.jd.com
http_access deny http bad_domain
使用curl测试黑名单,taobao、jd返回状态码为403,51cto不在黑名单返回200 OK;
[root@localhost ~]# curl -x192.168.22.30:3128www.taobao.com -I
HTTP/1.0 403 Forbidden
Server: squid/3.1.10
Mime-Version: 1.0
Date: Sun, 24 May 2015 21:35:22 GMT
Content-Type: text/html
Content-Length: 3266
X-Squid-Error: ERR_ACCESS_DENIED 0
Vary: Accept-Language
Content-Language: en
X-Cache: MISS from yonglinux
X-Cache-Lookup: NONE from yonglinux:3128
Via:1.0 yonglinux (squid/3.1.10)
Connection: keep-alive
[root@localhost ~]# curl -x192.168.22.30:3128www.jd.com -I
HTTP/1.0 403 Forbidden
Server: squid/3.1.10
Mime-Version: 1.0
Date: Sun, 24 May 2015 21:35:32 GMT
Content-Type: text/html
Content-Length: 3254
X-Squid-Error: ERR_ACCESS_DENIED 0
Vary: Accept-Language
Content-Language: en
X-Cache: MISS from yonglinux
X-Cache-Lookup: NONE from yonglinux:3128
Via:1.0 yonglinux (squid/3.1.10)
Connection: keep-alive
[root@localhost ~]# curl-x192.168.22.30:3128 www.51cto.com -I
HTTP/1.0 200 OK
Server: Tengine
Date: Sun, 24 May 2015 13:31:21 GMT
Content-Type: text/html
Vary: Accept-Encoding
Load-Balancing: web39
X-Cache: MISS from yonglinux
X-Cache-Lookup: MISS from yonglinux:3128
Via:1.0 yonglinux (squid/3.1.10)
Connection: keep-alive
使用IE浏览器测试,需要设置代理服务器,菜单栏——工具——Internet选项——连接——局域网设置,勾选代理服务器——高级,填写squid代理服务器地址和端口号;
原文地址:http://11583574.blog.51cto.com/11573574/1859246