content: ########## How To Use Docker Image ###############
  ##
  ##  Image Name: denny/devubuntu:v1
  ##  Install docker utility
  ##  Download docker image: docker pull denny/devubuntu:v1
  ##  Boot docker container: docker run -t -d denny/devubuntu:v1 /usr/sbin/sshd -D
  ##
  ##     ruby --version
  ##     gem --version
  ##     bundle --version
  ##     gem sources -l
  ##     python --version
  ##     java -version
  ##     chef-solo --version
  ##     nc -l 80
  ##     which pidstat
  ##################################################
  
  FROM denny/sshd:v1
  MAINTAINER DennyZhang.com <http://dennyzhang.com>
  
  ########################################################################################
  apt-get update
  apt-get install -y lsof vim strace ltrace tmux curl tar telnet
  apt-get install -y software-properties-common python-software-properties tree
  apt-get install -y build-essential openssl git-core
  apt-get install -y libcurl3 openssh-client openssh-server
  apt-get install -y python-pip python-dev
  apt-get install -y sysstat
  # http://xmodulo.com/record-replay-terminal-session-linux.html
  pip install TermRecord
  
  # TODO: install ruby2.1
  apt-get -yqq install python-software-properties && \
  apt-add-repository ppa:brightbox/ruby-ng && \
  apt-get -yqq update && \
  apt-get -yqq install ruby2.1 ruby2.1-dev && \
  rm -rf /usr/bin/ruby && \
  ln -s /usr/bin/ruby2.1 /usr/bin/ruby && \
  rm -rf /usr/local/bin/ruby /usr/local/bin/gem /usr/local/bin/bundle
  
  # sete locale to UTF-8
  locale-gen --lang en_US.UTF-8 && \
  cat > /etc/profile.d/locale.sh <<EOF
  export LANG=en_US.UTF-8
  export LANGUAGE=en_US.UTF-8
  export LC_CTYPE=en_US.UTF-8
  EOF && \
  
  chmod o+x /etc/profile.d/locale.sh
  
  # install java8
  add-apt-repository ppa:webupd8team/java
  apt-get -y update && \
  apt-get -y install oracle-java8-installer
  
  # install docker
  wget -qO- https://get.docker.com/ | sh
  
  # stop services
  service docker stop
  
  # install chef
  curl -L https://www.opscode.com/chef/install.sh | bash
  
  # change ruby gem sources
  # gem sources -a https://ruby.taobao.org/ && \
  # gem sources -r https://rubygems.org/ && \
  # gem sources -r http://rubygems.org/
  
  # install nc and tcpdump
  apt-get install netcat
  apt-get install tcpdump
  
  # install inotify
  apt-get install inotify-tools
  
  # http://justniffer.sourceforge.net/#!/install
  sudo add-apt-repository ppa:oreste-notelli/ppa
  sudo apt-get update
  sudo apt-get install justniffer
  
  # install nagios
  apt-get install bc
  apt-get install nagios-nrpe-server nagios-plugins nagios-nrpe-plugin
  apt-get install nagios-plugins-basic libsys-statistics-linux-perl nagios3
  apt-get install librrds-perl libgd-gd2-perl net-tools
  
  apt-get install --force-yes -y sudo openssh-server curl lsb-release
  
  # TODO: install nethogs for debugging network issue
  # http://www.tecmint.com/nethogs-monitor-per-process-network-bandwidth-usage-in-real-time/
  cd /tmp
  wget -c https://github.com/raboof/nethogs/archive/v0.8.1.tar.gz
  tar xf v0.8.1.tar.gz
  cd ./nethogs-0.8.1/
  # Install dependencies and build
  sudo apt-get install -y libncurses5-dev libpcap-dev
  make && sudo make install
  # Check and run: nethogs -V
  
  # TODO: install htop
  apt-get install -y htop
  
  apt-get update
  
  # clean up
  rm -rf /var/cache/*
  rm -rf /tmp/* /var/tmp/*
  rm -rf /usr/share/doc && \
  apt-get autoremove && \
  apt-get clean && apt-get autoclean
  ########################################################################################
  