Polipo is a small and fast caching web proxy (a web cache, an HTTP proxy, a proxy server). While Polipo was designed to be used by one person or a small group of people, there is nothing that prevents it from being used by a larger group.

docker-compose.yml

version: "3.8"
services:
  polipo:
    image: vimagick/polipo
    command:
      authCredentials=username:password
      socksParentProxy=1.2.3.4:9050
      dnsNameServer=8.8.8.8
    ports:
      - "8123:8123"
    restart: unless-stopped

server

$ docker-compose up -d

client

$ curl -x http://username:password@server:8123 https://www.youtube.com/