Hello,

in order to be able to install RedHat Coreos via PXE it is required to add RedHat Coreos as a new operating system because the filenames on the Red Hat mirror don't fit to any existing naming conventions.

For example:
rhcos-4.1.0-x86_64-installer-initramfs.img
rhcos-4.1.0-x86_64-installer-kernel
http://mirror.openshift.com/pub/openshift-v4/dependencies/rhcos/4.1/4.1.0/

A simple example for the code would be:

app/models/operatingsystems/rhcos.rb

class Rhcos < Operatingsystem
  PXEFILES = {:kernel => 'rhcos-4.1.0-x86_64-installer-kernel', :initrd => 'rhcos-4.1.0-x86_64-installer-initramfs.img'}

  def pxe_type
    'coreos'
  end

  def mediumpath(medium_provider)
    ''
  end

  def pxedir
    ''
  end

  def display_family
    'Rhcos'
  end

end

app/models/operatingsystems/operatingsystem.rb

  FAMILIES = { 'Debian'    => %r{Debian|Ubuntu}i,
               'Redhat'    => %r{RedHat|Centos|Fedora|Scientific|SLC|OracleLinux}i,
               'Suse'      => %r{OpenSuSE|SLES|SLED}i,
               'Windows'   => %r{Windows}i,
               'Altlinux'  => %r{Altlinux}i,
               'Archlinux' => %r{Archlinux}i,
               'Coreos'    => %r{CoreOS}i,
               'Rhcos'     => %r{Rhcos}i,
               'Gentoo'    => %r{Gentoo}i,
               'Solaris'   => %r{Solaris}i,
               'Freebsd'   => %r{FreeBSD}i,
               'AIX'       => %r{AIX}i,
               'Junos'     => %r{Junos}i,
               'NXOS'      => %r{NX-OS}i,
               'Xenserver' => %r{XenServer}i }