NAJA2 Docker Socket Forwarding

I wanted to federate my two docker hosts so I can manage them from one interface (portainer, watchtower...), but without exposing the HTTP socket.

This project creates the infrastructure to forward a socket from a host locally.

Requirements

On the local machine (the one wanding to access the remote socket)

• (A service account)
• A folder socks in /etc/docker

  sudo mkdir /etc/docker
  

On the remote machine

• Docker (duh)
• A normal user account (it needs to be able to accept SSH connections)
• Permission to access the docker socket

Usage

On the local machine

• Copy and paste and fill .ssh/config with the host and the hostname.
• Set up the remote machine's host key in .ssh/known_hosts
• Generate an identity file with ssh-keygen

  ssh-keygen -b 256 -C "docker@$(hostname)" -f ~/.ssh/id_ecdsa -t ecdsa
  

• Create a (sym)link to the docker@.service to /lib/systemd/system/ and reload systemd

  sudo ln -s docker@.service /lib/systemd/system/
  sudo systemctl daemon-reload
  

On the remote machine

• Copy and paste .ssh/authorized_keys, then fill with the public part of the key.

On the local machine

• Start the service