echo -e 'Acquire::http { Proxy “http://apt.hackenopenair.de:3142”; }\nAcquire::https::proxy “DIRECT”;' | sudo tee /etc/apt/apt.conf.d/hoa-proxyapt install auto-apt-proxy (use http in your source.list to benefit from the cache)deb http://172.29.0.2:3142/debian stable main contrib non-free in your sources.list (also with other releases)