Configure Web Proxy on CentOS 7 configuration

System-wide proxy settings - add the following lines to your /etc/environment file:
# vi /etc/environment
http_proxy="http://proxysrv:8080/"
https_proxy="https://proxysrv:8080/"
ftp_proxy="ftp://proxysrv:8080/"
no_proxy=".mylan.local,.domain1.com,host1,host2"

Configure yum to use proxy:
# vi /etc/yum.conf
proxy=http://proxysrv:8080/