#precondition
one of those listed below is installed.
docker for mac / docker for windows / docker toolbox for windows

#commands to create rails 5.0 environment using docker
git clone https://github.com/kappyhappy/docker_rails
cd docker_rails

#create rails project
docker-compose run web rails new . --force --database=mysql

#build rails project
docker-compose build

#modify default password and host.
vi config/database.yml

#in my case, default part is started from row number 12.

default: &default adapter: mysql2 encoding: utf8 pool: 5 username: root password: password host: db

#update db settings
docker-compose up -d

#check current docker status
docker-compose ps

#create db if not exists
docker-compose run web bundle exec rake db:create

#check whether rails screen is available when accessing to localhost:3000 with your browser
localhost:3000

#if you use docker toolbox for windows, check IP first and try to see with your browser
docker-machine ip default

#type IP checked above instead of localhost
http://IP:3000