Let's you cache debian packages.

Here's my deployment.

Now when auto installing linux I can point it to this as a proxy

#cloud-config
autoinstall:
  version: 1
  proxy: http://git.local-domain:8000/

However this doesn't cache https traffic.  Squid just forwards this straight to the origin server so it has no way to cache it.

For an https connection we see this in /var/log/squid/access.log

1596531928.807     94 10.0.0.2 TCP_TUNNEL/200 2013 CONNECT registry.local-domain:5003 - HIER_DIRECT/192.168.2.1 -

This repo shows how to run squid in various different modes.

docker run  -p 3128:3128 -ti docker.io/salrashid123/squidproxy /bin/bash

This deploys a squid caching proxy with a self signed CA.  If you trust the CA you can use the service.