Downloading the same software packages for Debian/Ubuntu-based distributions for several machines in your network over and over again is slow and annoying. Using apt-cacher you can set up a central machine that caches the package files after the first download. This is a minimal docker image that eases setting up and maintaining your apt-cacher proxy server.
$ git clone https://github.com/clue/docker-apt-cacher.git
$ cd docker-apt-cacher
$ sudo docker build -t apt-cacher .$ sudo docker run -d -p 3142:3142 -t apt-cacher$ echo "Acquire::http::Proxy \"http://your-docker-host:3142\";" | sudo tee /etc/apt/apt.conf.d/01proxy