Docker has a 42 AUFS layer limit, this limits each image to 1 layer

@jpetazzo is this a step in the right direction? moby/moby#2028

Dockerfile.precise

@@ -1,11 +1,4 @@
 FROM ubuntu:12.04
-MAINTAINER How are you? "docker@howareyou.com"
+# MAINTAINER How are you? "docker@howareyou.com"
 
-RUN echo 'APT::Get::Assume-Yes "true";' > /etc/apt/apt.conf.d/90forceyes
-RUN echo 'deb http://archive.ubuntu.com/ubuntu precise main universe' > /etc/apt/sources.list
-RUN apt-get update
-
-RUN dpkg-divert --local --rename --add /sbin/initctl
-RUN ln -s /bin/true /sbin/initctl
-
-RUN apt-get install wget
+RUN echo "export HOME=/root" > /.profile; echo 'APT::Get::Assume-Yes "true";' > /etc/apt/apt.conf.d/90forceyes; echo 'deb http://archive.ubuntu.com/ubuntu precise main universe' > /etc/apt/sources.list; apt-get update; dpkg-divert --local --rename --add /sbin/initctl; ln -s /bin/true /sbin/initctl; apt-get install wget

Dockerfile.ruby-build

@@ -1,13 +1,4 @@
 FROM howareyou/precise
-MAINTAINER How are you? "docker@howareyou.com"
+# MAINTAINER How are you? "docker@howareyou.com"
 
-ENV RUBY_BUILD_VERSION 20130806
-
-RUN apt-get install build-essential
-RUN apt-get install libssl-dev
-RUN apt-get install zlib1g-dev
-RUN apt-get install libreadline-dev
-RUN apt-get install ca-certificates
-
-RUN wget -O - https://github.com/sstephenson/ruby-build/archive/v$RUBY_BUILD_VERSION.tar.gz | tar -C /usr/local/src -zxv
-RUN cd /usr/local/src/ruby-build-$RUBY_BUILD_VERSION && sh install.sh
+RUN echo "export RUBY_BUILD_VERSION=20130806" >> /.profile; . /.profile; apt-get install build-essential libssl-dev zlib1g-dev libreadline-dev ca-certificates; wget -O - https://github.com/sstephenson/ruby-build/archive/v$RUBY_BUILD_VERSION.tar.gz | tar -C /usr/local/src -zxv; cd /usr/local/src/ruby-build-$RUBY_BUILD_VERSION && sh install.sh

Dockerfile.ruby.1.9

@@ -1,10 +1,4 @@
-FROM howareyou/ruby-build_20130806
-MAINTAINER How are you? "docker@howareyou.com"
+FROM howareyou/ruby-build:20130806
+# MAINTAINER How are you? "docker@howareyou.com"
 
-ENV RUBY_VERSION 1.9.3-p448
-ENV PATH /usr/local/lib/$RUBY_VERSION/bin:$PATH
-
-RUN ruby-build -v $RUBY_VERSION /usr/local/lib/$RUBY_VERSION
-
-RUN echo "gem: --no-rdoc --no-ri" > /root/.gemrc
-RUN gem install bundler foreman pry
+RUN echo "export RUBY_VERSION=1.9.3-p448" >> /.profile; echo "export PATH=/usr/local/lib/$RUBY_VERSION/bin:$PATH" >> /.profile; . /.profile; ruby-build -v $RUBY_VERSION /usr/local/lib/$RUBY_VERSION; echo "gem: --no-rdoc --no-ri" > /root/.gemrc; gem install bundler foreman pry

Dockerfile.ruby.2.0

@@ -1,10 +1,4 @@
-FROM howareyou/ruby-build_20130806
-MAINTAINER How are you? "docker@howareyou.com"
+FROM howareyou/ruby-build:20130806
+# MAINTAINER How are you? "docker@howareyou.com"
 
-ENV RUBY_VERSION 2.0.0-p247
-ENV PATH /usr/local/lib/$RUBY_VERSION/bin:$PATH
-
-RUN ruby-build -v $RUBY_VERSION /usr/local/lib/$RUBY_VERSION
-
-RUN echo "gem: --no-rdoc --no-ri" > /root/.gemrc
-RUN gem install bundler foreman pry
+RUN echo "export RUBY_VERSION=2.0.0-p247" >> /.profile; echo "export PATH=/usr/local/lib/$RUBY_VERSION/bin:$PATH" >> /.profile; . /.profile; ruby-build -v $RUBY_VERSION /usr/local/lib/$RUBY_VERSION; echo "gem: --no-rdoc --no-ri" > /root/.gemrc; gem install bundler foreman pry