Squid is too much hassle to set up, and Polipo works well but is discontinued. What are the alternatives for forward caching proxies that are very easy to set up? If possible with just a one-liner, like this:
./proxy -listen 0.0.0.0:1080 \
-auth username:password \
-cachedir /tmp/cache
Either http/https or socks5 proxy are all OK.