Dockerfile in markdo-0.1.12.alpha vs Dockerfile in markdo-0.2.0

@@ -1,18 +1,32 @@
-FROM alpine:3.4
+FROM ubuntu:16.04
 
-RUN echo 'apk update && apk add "$1"' > /usr/local/bin/pkg-apk
+RUN echo 'apt-get update && apt-get install --no-install-recommends -y "$1"' > /usr/local/bin/pkg-deb
+RUN echo 'gem install --no-ri --no-rdoc "$1"' > /usr/local/bin/pkg-gem
+RUN echo 'npm install --global "$1"' > /usr/local/bin/pkg-npm
 RUN chmod +x /usr/local/bin/pkg-*
 
 # Used for building the gem
-RUN pkg-apk git
+RUN pkg-deb git=1:2.7.4-0ubuntu1
 
-RUN pkg-apk ruby
-RUN pkg-apk ruby-bundler
+# The Ubuntu-provided `phantomjs` is quite old.  The below solution installs way more Node.js stuff than I'd like, but otherwise it's pretty painless.
+RUN pkg-deb npm=3.5.2-0ubuntu4
+RUN pkg-deb nodejs-legacy=4.2.6~dfsg-1ubuntu4
+RUN pkg-deb libfontconfig1=2.11.94-0ubuntu1.1
+RUN pkg-deb bzip2=1.0.6-8
+RUN pkg-npm phantomjs-prebuilt@2.1.12
 
+RUN pkg-deb build-essential=12.1ubuntu2
+RUN pkg-deb ruby2.3
+RUN pkg-deb ruby2.3-dev
+
+RUN pkg-deb libffi-dev=3.2.1-4
+RUN pkg-gem ffi:1.9.14
+
+RUN pkg-gem bundler:1.12.5
 COPY Gemfile $HOME/
 COPY lib/markdo/fake_version.rb $HOME/lib/markdo/version.rb
-
 COPY markdo.gemspec $HOME/
-RUN bundle
+RUN bundle install
 
 WORKDIR /src
+CMD guard --no-bundler-warning