anchor.diff:  
   RUN chmod u+s /bin/ping
   
  -RUN mkdir /tmp/nagios
  -RUN wget http://downloads.sourceforge.net/project/nagios/nagios-4.x/nagios-$VERSION/nagios-$VERSION.tar.gz --output-document=/tmp/nagios.tar.gz
  -RUN cd /tmp; tar -xaf /tmp/nagios.tar.gz --strip-components=1 --directory=/tmp/nagios/
  -
  -RUN mkdir /tmp/nagios-plugins
  -RUN wget http://www.nagios-plugins.org/download/nagios-plugins-$PLUGINS_VERSION.tar.gz --output-document=/tmp/nagios-plugins.tar.gz
  -RUN cd /tmp; tar -xaf /tmp/nagios-plugins.tar.gz --strip-components=1 --directory=/tmp/nagios-plugins/
  -
  +## Create Nagios specific users & groups
   RUN /usr/sbin/useradd -m nagios; \
   	/usr/sbin/groupadd nagcmd; \
   	/usr/sbin/usermod -a -G nagcmd nagios; \
   	/usr/sbin/usermod -a -G nagcmd apache;
   
  +## Download Nagios
  +RUN mkdir /tmp/nagios
  +RUN wget http://downloads.sourceforge.net/project/nagios/nagios-4.x/nagios-$VERSION/nagios-$VERSION.tar.gz --output-document=/tmp/nagios.tar.gz
  +RUN cd /tmp; tar -xaf /tmp/nagios.tar.gz --strip-components=1 --directory=/tmp/nagios/
  +
  +## Compile Nagios
   RUN cd /tmp/nagios; \
   	./configure --with-command-group=nagcmd; \
   	make all; \
  
positive.code: FROM centos:latest
  
  ENV VERSION 4.3.1
  ENV PLUGINS_VERSION 2.1.4
  ENV API_VERSION 1.0.1
  
negative.code: 	mysql-devel \
  	perl-CPAN;
  
  ## Install CPAN and Nagios dependencies
  RUN perl -MCPAN -Mlocal::lib=~/perl5 -e 'my $c = "CPAN::HandleConfig"; $c->load(doit => 1, autoconfig => 1); $c->edit(prerequisites_policy => "follow"); $c->edit(build_requires_install_policy => "yes"); $c->commit'
  RUN cpan install \
  	Test::More \
  