echo 'Acquire::http::proxy "http://192.168.4.1:12080/";' >> /etc/apt/apt.conf.d/apt-get.confhttps://qiita.com/charon/items/1587f0092d085371d15d
sudo vim /etc/apt/apt.conf.d/proxyAcquire::http::proxy "http://[your-proxy-host]:[your-proxy-port]/";
Acquire::https::proxy "http://[your-proxy-host]:[your-proxy-port]/";