我们使用nginx做过正向代理的设定，但是如果希望支持https的话，直接使用nginx则较为困难，而使用在这方面术业有专攻的squid则要简单的多。这篇文章用于记录在centos7上安装和设定squid3.5来实现http和https的步骤。
机器配置
[root@liumiaocn ~]# uname -a Linux mail.163.com 3.10.0-514.el7.x86_64 #1 SMP Tue Nov 22 16:42:41 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux [root@liumiaocn ~]# [root@liumiaocn ~]# cat /etc/redhat-release CentOS Linux release 7.3.1611 (Core) [root@liumiaocn ~]#
安装squid
安装命令： yum install squid
确认版本
版本确认： rpm -qa |grep squid
[root@liumiaocn ~]# rpm -qa |grep squid squid-migration-script-3.5.20-12.el7.x86_64
squid-3.5.20-12.el7.x86_64 [root@liumiaocn ~]#
确认ip_forward
ip_forward需要设定为1，缺省centos已设定，详细如下：
[root@liumiaocn ~]# sysctl -a |grep -w ip_forward net.ipv4.ip_forward = 1 [root@liumiaocn ~]#
修改设定文件
修改前
[root@liumiaocn ~]# grep -n 'http_access deny all' /etc/squid/squid.conf 56:http_access deny all [root@liumiaocn ~]#
修改后
[root@liumiaocn ~]# grep -n http /etc/squid/squid.conf |grep -w all 56:http_access allow all [root@liumiaocn ~]#
启动squid
systemctl start squid
问题1：libSSL错误
启动squid时提示如下错误
squid: relocation error: squid: symbol SSL_set_alpn_protos, version libssl.so.10 not defined in file libssl.so.10 with link time reference
原因：未安装openssl
对应方法: yum install openssl
安装之后启动squid即可：
[root@liumiaocn ~]# systemctl start squid [root@liumiaocn ~]# systemctl status squid ● squid.service - Squid caching proxy Loaded: loaded (/usr/lib/systemd/system/squid.service; disabled; vendor preset: disabled) Active: active (running) since Tue 2018-06-05 20:07:56 CST; 8s ago Process: 28548 ExecStart=/usr/sbin/squid $SQUID_OPTS -f $SQUID_CONF (code=exited, status=0/SUCCESS) Process: 28540 ExecStartPre=/usr/libexec/squid/cache_swap.sh (code=exited, status=0/SUCCESS) Main PID: 28551 (squid) Memory: 14.3M CGroup: /system.slice/squid.service ├─28551 /usr/sbin/squid -f /etc/squid/squid.conf ├─28553 (squid-1) -f /etc/squid/squid.conf └─28557 (logfile-daemon) /var/log/squid/access.log Jun 05 20:07:56 liumiaocn systemd[1]: Starting Squid caching proxy... Jun 05 20:07:56 liumiaocn squid[28551]: Squid Parent: will start 1 kids Jun 05 20:07:56 liumiaocn squid[28551]: Squid Parent: (squid-1) process 28553 started Jun 05 20:07:56 liumiaocn systemd[1]: Started Squid caching proxy. [root@liumiaocn ~]#
问题2:无法进行域名解析
此时发现无法使用域名只能使用ip来访问
原因：dns未配置，在squid的配置文件中添加8.8.8.8和8.8.4.4
[root@liumiaocn ~]# grep nameserver /etc/squid/squid.conf dns_nameservers 8.8.8.8 8.8.4.4 [root@liumiaocn ~]# [root@liumiaocn ~]# systemctl restart squid [root@liumiaocn ~]#
客户端的访问
squid的缺省port为3128，在这里没有修改，在客户端使用如下方式即可访问：
http方式
export http_proxy=http://192.168.163.117:3128
curl http://www.xxx.com
https方式
export https_proxy=http://192.168.163.117:3128
curl https://www.xxx.com
打开文件/etc/profile
在文件的末端输入：
http_proxy=http://username:password@proxy_ip:port/
https_proxy=http://username:password@proxy_ip:port/
ftp_proxy=http://username:password@proxy_ip:port/
export http_proxy
export https_proxy
export ftp_proxy
3.关闭文件，命令行输入
source /etc/profile
现在可以通过代理上网喽。
例子
http_proxy=http://175.6.12.82:3128/
https_proxy=http://175.6.12.82:3128/
ftp_proxy=http://175.6.12.82:3128/
export http_proxy
export https_proxy
export ftp_proxy