Rails Docker Setup

database.yml

default: &default
  adapter: mysql2
  encoding: utf8
  pool: 5
  username: root
  password: root
  post: 3306
  host: mysql

development:
  <<: *default
  database: rails-app_development

docker-composer.yml

version: '2'
services:
  mysql:
    image: mariadb
    volumes:
      - ~/Projects/database_data:/var/lib/mysql 
    environment:
      - MYSQL_ROOT_PASSWORD=root
    ports:
      - "3306:3306"
  web:
    build: .
    command: bundle exec rails s -e rudi -p 3000 -b '0.0.0.0'
    volumes:
      - .:/usr/local/rails-app
    working_dir: /usr/local/rails-app
    ports:
      - "3000:3000"
    depends_on:
      - mysql

Dockerfile

FROM ruby:2.3.1
RUN apt-get update -qq && apt-get install -y build-essential libpq-dev nodejs
RUN apt-get install -y imagemagick
RUN mkdir /usr/local/rails-app
WORKDIR /usr/local/rails-app
ADD Gemfile Gemfile
ADD Gemfile.lock Gemfile.lock
RUN bundle install

Gemfile

source 'https://rubygems.org'
gem 'rails', '4.2.7.1'
gem 'mysql2', '~> 0.3.18'