[TOC] 如果主机不能连外网，则我们可以为yum源配置一个能连外网的代理服务器，这样我们就可以继续使用yum命令安装软件。 **注意： 设置http_proxy环境变量，并不能达到让yum能连外网。yum连外网有自已的设置方法。** ### **全局设置** 假设我们想要为 `/etc/yum.repos.d/` 下的所有仓库设置代理，则可以修改 `/etc/yum.conf` 文件，在该文件尾部添加如下一行： ``` proxy=http://username:password@ip:port ``` ### **特定仓库** 比如`CentOS-Base.repo`中有三个仓库：base、updates和extras。我们只想给base仓库设置代理，则只需要在base仓库后面添加一行，如下： ``` [base] name=CentOS-$releasever - Base #mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os&infra=$infra baseurl=http://mirror.centos.org/centos/$releasever/os/$basearch/ gpgcheck=1 gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7 proxy=http://ip:port #released updates [updates] name=CentOS-$releasever - Updates #mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=updates&infra=$infra baseurl=http://mirror.centos.org/centos/$releasever/updates/$basearch/ gpgcheck=1 gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7 #additional packages that may be useful [extras] name=CentOS-$releasever - Extras #mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=extras&infra=$infra baseurl=http://mirror.centos.org/centos/$releasever/extras/$basearch/ gpgcheck=1 gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7 ``` ### **特定仓库不走代理** 假设我们在/etc/yum.conf中设置了全局代理，但是又想某个仓库不走代理，此时，我们只需要在特定的仓库后面添加一行 `proxy=_none_ `即可。比如 `CentOS-Base.repo`中有三个仓库，我们希望base仓库不走代理，则设置如下： ``` [base] name=CentOS-$releasever - Base #mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os&infra=$infra baseurl=http://mirror.centos.org/centos/$releasever/os/$basearch/ gpgcheck=1 gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7 proxy=_none_ #released updates [updates] name=CentOS-$releasever - Updates #mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=updates&infra=$infra baseurl=http://mirror.centos.org/centos/$releasever/updates/$basearch/ gpgcheck=1 gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7 #additional packages that may be useful [extras] name=CentOS-$releasever - Extras #mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=extras&infra=$infra baseurl=http://mirror.centos.org/centos/$releasever/extras/$basearch/ gpgcheck=1 gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7 ``` ### **常用的Yum代理软件** 上面我们说可以给Yum配置代理，常用的代理软件一般为squid，参考[《安装squid》]()