Setup a Modx CMS on Docker.
mkdir modx_doc
~/code/Docker_project: cd modx_doc
~/code/Docker_projects/modx_doc

git clone https://github.com/modxcms/docker-modx.git
Edit the docker-compose yml file:

version: '3'
services:
  web:
    image: maki/modx
    links:
      - 'db:mysql'
    ports:
      - '8787:80'
    environment:
      MODX_VERSION: 2.7.0
      MODX_DB_HOST: 'mysql:3306'
      MODX_DB_PASSWORD: modx
      MODX_DB_USER: modx
      MODX_DB_NAME: modx
    volumes:
      - './html:/var/www/html'
  db:
    image: 'mysql:5.7'
    environment:
      MYSQL_ROOT_PASSWORD: mysql
      MYSQL_DATABASE: modx
      MYSQL_USER: modx
      MYSQL_PASSWORD: modx
    ports:
      - '3307:3306'
    command: mysqld --sql-mode=NO_ENGINE_SUBSTITUTION
    volumes:
      - './mysql:/var/lib/mysql'
  phpmyadmin:
    image: corbinu/docker-phpmyadmin
    links:
      - 'db:mysql'
    ports:
      - 9797:80
    environment:
      MYSQL_USERNAME: modx
      MYSQL_ROOT_PASSWORD: mysql 
      MYSQL_DATABASE: modx
      MYSQL_USER: modx