Rails 4:
a.sh
:
#!/bin/sh -eu
apk add build-base sqlite-dev nodejs tzdata
cat <<GEMFILE >Gemfile
source 'https://rubygems.org'
gem 'rails', '~> 4.0'
gem 'nokogiri', '< 1.11.0'
GEMFILE
bundle
rails new app
cd app
sed -Ei "s/gem 'sqlite.*/gem 'sqlite3', '~> 1.3.6'/" Gemfile
bundle
read
$ docker run --rm -itv $PWD/a.sh:/a.sh ruby:2.4-alpine ./a.sh