Add ssh access to a wordpress docker-compose setup.

docker-compose.yml

version: '2'

services:
   db:
     image: mysql:5.7
     volumes:
       - db_data:/var/lib/mysql
     restart: always
     environment:
       MYSQL_ROOT_PASSWORD: somewordpress
       MYSQL_DATABASE: wordpress
       MYSQL_USER: wordpress
       MYSQL_PASSWORD: wordpress

   wordpress:
     depends_on:
       - db
     image: wordpress:latest
     ports:
       - "8000:80"
     restart: always
     environment:
       WORDPRESS_DB_HOST: db:3306
       WORDPRESS_DB_USER: wordpress
       WORDPRESS_DB_PASSWORD: wordpress

   ssh:
     image: tutum/ubuntu
     volumes_from: 
       - wordpress
     depends_on:
       - wordpress
       - db
     ports:
       - "2222:22"
     restart: always
     environment:
        AUTHORIZED_KEYS: "CHANGEME"
volumes:
    db_data: