These are images we use at kyan.com as a base image to simplify local development of Rails app. This image uses ubuntu:16.04 as a base and allows you to install a specific version of Ruby you need to use. It contains all the base dependencies you need to compile most common gems we use, including MySQL or Postgres.
kyan/rails_legacy
You could then create a local Dockerfile using:
FROM kyan/rails_legacy
MAINTAINER user@kyan.com
ENV REFRESHED_AT 2016-07-27
# Choose your ruby version
ENV RUBY_VERSION 'ruby 1.9.3-p551'
# Install Ruby
RUN ruby-install --system $RUBY_VERSION
# Install RubyGems
RUN gem update --system --no-rdoc --no-ri
# Install Bundler
RUN gem install bundler --no-rdoc --no-ri
# Install gems
ADD Gemfile /app/Gemfile
ADD Gemfile.lock /app/Gemfile.lock
RUN bundle install