Create new rails project by docker one off ruby container

bash

# Start a new, one-off ruby container running a bash shell. It should have the
# current directory mounted at '/usr/src':
docker run --rm -ti -v $(pwd):/usr/src -w /usr/src ruby:2.2.6 bash

# Now that your'e running bash inside our one-off container, install rails and generate the app.
gem install rails --no-rdoc --no-ri && rails new my-app --database=postgresql

# Exit the one-off container. The container should be removed automatically.
exit