What is docker-init and docker-proxy

If one compiles docker 17.03.1 he sees the following binaries:

  • docker-init
  • docker-proxy
  • docker-containerd-sh
  • docker-runc
  • docker-containerd-ct
  • docker-containerd
  • dockerd

What is docker-init and docker-proxy? I was looking at the project tree and couldn’t find such projects by docker only:


For the rest, e.g. containerd it’s clear to me that the source is located at "github.com/docker/containerd/containerd", but for the docker-proxy and docker-init it’s not clear at all. Where can I find them?