client.dock

FROM ubuntu:16.04

RUN apt-get update -y && apt-get -y install openssh-client

docker-compose.yml

version: '3'

services:
  server:
    build:
      context: .
      dockerfile: server.dock
  client:
    build:
      context: .
      dockerfile: client.dock
    command: "/bin/bash -c 'while :; do sleep 1000; done'"

run.sh

docker-compose up -d

docker-compose exec client ssh sshuser@server

server.dock

FROM nodered/node-red-docker:latest

USER root
RUN apt-get update -y \
    && apt-get -y install openssh-server \
    && adduser --disabled-password --gecos '' sshuser \
    && echo sshuser:password | chpasswd \
    && mkdir /var/run/sshd

EXPOSE 22

CMD ["/bin/sh", "-c", "/usr/sbin/sshd && npm start -- --userDir /data"]