how to use proxy on centos7

1. system

   edit /etc/profile, like this:

   vi /etc/profile
   all_proxy=socks5://username:password@ip:port
   no_proxy=127.0.0.1,10.0.0.0/8,172.16.0.0/12,192.168.0.0/16
   export all_proxy no_proxy
   source /etc/profile
   

2. docker

   edit /usr/lib/systemd/system/docker.service, like this:

   vi /usr/lib/systemd/system/docker.service
   [Service]
   Environment=HTTP_PROXY=socks5://username:password@ip:port
   Environment=NO_PROXY=127.0.0.1,10.0.0.0/8,172.16.0.0/12,192.168.0.0/16
   systemctl daemon-reload && systemctl restart docker
   

   now, you can smoothly install kubernetes in china.

3. yum

   edit /etc/yum.conf, like this:

   vi /etc/yum.conf
   [main]
   proxy=socks5://ip:port
   proxy_username=user
   proxy_password=password