Dockerfile derived from official PostgreSQL with rvm/ruby/rails

Dockerfile

### Container based on official postgres v9.5.3, with:
# * rvm
# * ruby 2.2.3
# * rails 4.2.3
###

FROM postgres:9.5.3

RUN apt-get update && apt-get install -y curl git libpq-dev
RUN gpg --keyserver hkp://keys.gnupg.net --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3
RUN /bin/bash -l -c "curl -sSL https://get.rvm.io | bash -s stable"
RUN /bin/bash -l -c "rvm install 2.2.3"
RUN /bin/bash -l -c "rvm use 2.2.3 --default"
RUN /bin/bash -l -c "ruby -v"
RUN /bin/bash -l -c "gem install bundler"
RUN /bin/bash -l -c "gem install rails -v 4.2.3"
RUN echo 'source /etc/profile.d/rvm.sh' >> ~/.bashrc

### Building:
# $ docker build -t pg-rails .
###

### Running in foreground:
# $ docker run --rm -P -p 3000:3000 -p 5432:5432 -v "$(pwd):/webapp" --name pg-rails-test pg-rails
# options:
# --rm will remove the container when the process ends
# -p X:Y forward the port X from container, to Y on host
# -v X:Y share (mount) the X folder from host, on Y folder on container
#
# Running in background:
# $ docker run -P -p 3000:3000 -p 5432:5432 -v "$(pwd):/webapp" -d --name pg-rails-test pg-rails
#
# go to the running container (other shell):
# $ docker exec -i -t pg-rails-test '/bin/bash'
# (root @ container)
# $ cd /webapp
# $ rails s -b 0.0.0.0
#
# If you are using the gem webconsole to debug, configure your application as described here:
#   https://github.com/rails/web-console#configweb_consolewhitelisted_ips
###

### Helpers:
# Remove all containers:
# $ docker rm $(docker ps -qa)
# Remove all untagged images:
# $ docker rmi -f $(docker images | grep '^<none>' | awk '{print $3}')
###