Leverage Docker to build Ruby RPMs

These instructions are tested on Mac OSX, Yosemite and newer:

1. Make sure Docker is running (recommend the new Docker beta)
2. FIXME: Clone this repo to the ~/uproj directory, as the script relies on this location
3. Run:

./build6.sh

or

./build7.sh

Depending on building for Centos6 or Centos7.

---

####General steps scripted:

Install packages to build RPMs in general:

sudo yum -y install rpmdevtools

Install libary packages:

sudo yum -y install glibc-devel readline-devel libyaml-devel ncurses-devel gdbm-devel tcl-devel openssl-devel db4-devel libffi-devel

Install some development tools:

sudo yum -y install make gcc unzip byacc

Create build environment for RPMs:

mkdir -p rpmbuild/{BUILD,RPMS,SOURCES,SPECS,SRPMS}
cd rpmbuild

Get the spec file and ruby sources:

wget https://github.com/kcrawford/ruby/raw/master/ruby.spec -O SPECS/ruby.spec
wget https://cache.ruby-lang.org/pub/ruby/2.2/ruby-2.2.3.tar.gz -O SOURCES/ruby-2.2.3.tar.gz

Build the RPM

rpmbuild -ba SPEC/ruby.spec

Have fun with ruby ;-)