This is based on Jessie Frazelle's jess/privoxy image (github, blog post) with a few very minor tweaks (turned off debug logging, pinned alpine version, container is versioned).
Example usage: run a privoxy in a container and link to a tor socks proxy container:
docker run -d \
--restart always \
# the link inside the container must be named "torproxy"
--link torproxy:torproxy \
-v /etc/localtime:/etc/localtime:ro \
-p 8118:8118 \
--name privoxy \
hyperiongray/privoxy
Dockerhub link: https://hub.docker.com/r/hyperiongray/privoxy/