add export http_proxy=http://server-proxy:port and / or export ftp_proxy=http://server-proxy:port in your profile (.bashrc) or in /etc/bash.bashrc file

Ubuntu / Debian For apt-get at the command-line If you originally setup ubuntu server behind a proxy, the settings are stored in “apt” itself, Checkout the following file: /etc/apt/apt.conf else modify it as below: Acquire::http::Proxy “<http://your proxy:port/”;