$ yum update
$ yum -y upgrade; reboot
$ yum install ruby-devel.x86_64
$ yum install -y libxml2-devel libxslt-devel
$ yum install -y autoconf automake libtool bison
$ yum install -y gcc-c++ patch readline readline-devel zlib zlib-devel
$ yum install -y libyaml-devel libffi-devel openssl-devel make bzip2
$ gem install public_suffix -v 2.0.5
$ yum info ruby # Needs to be v2.2+
$ curl -sSL https://rvm.io/mpapis.asc | gpg --import - # From here see https://tecadmin.net/install-ruby-latest-stable-centos
$ curl -L get.rvm.io | bash -s stable
$ source /etc/profile.d/rvm.sh
$ rvm reload
$ rvm requirements run
$ rvm install 2.5 # This may take a while
$ rvm list
$ rvm use 2.5 --default
$ ruby --version
$ gem update # Errors not related to kubeclient or kube_auto_analyzer don't stop it working
$ gem install --no-document json kubeclient kube_auto_analyzer