As I installed Icehouse, I recorded the changes I needed to make in Puppet, and have the following list, but don't remember exactly which one of the changes fixed this one. I'm also not sure if the *.rb files absolutely needed to be changed, or if they are only used for testing. But, here is the list, AIO installs on CentOS 7 with all of these changes. Note that this is not real diff output, but copy/paste of the after, and retroactively changing it to the before:

/usr/share/openstack-puppet/modules/mysql/manifests/params.pp: line 40:
<        'RedHat': {
<          if $::operatingsystemrelease >= 7 {
>        'RedHat','CentOS': {
>          if $::operatingsystemmajrelease >= 7 {

/usr/lib/python2.7/site-packages/packstack/puppet/templates/prescript.pp: line 37:
< if $::operatingsystem in $el_releases and $::operatingsystemmajrelease < 7 {
> if $::operatingsystem in $el_releases and $::operatingsystemmajrelease < 7 {
/usr/lib/python2.7/site-packages/packstack/puppet/templates/amqp.pp: line 47:
>      if $::operatingsystemrelease >= 7 {
>      if $::operatingsystemmajrelease >= 7 {
/usr/share/openstack-puppet/modules/nova/manifests/compute/libvirt.pp line 112
<  if($::osfamily == 'RedHat' and $::operatingsystem != 'Fedora') {
>  if($::osfamily == 'RedHat' and $::operatingsystem != 'Fedora' and $::osoperatingsystemmajrelease < 7) {
/usr/share/openstack-puppet/modules/nova/spec/classes/nova_compute_libvirt_spec.rb line 107
<        :operatingsystemrelease => 6.5 }
>        :operatingsystemmajrelease => 6.5 }
/usr/share/openstack-puppet/modules/nova/spec/classes/nova_compute_libvirt_spec.rb line 136
<          super().merge(:operatingsystemrelease => 7.0)
>          super().merge(:operatingsystemmajrelease => 7.0)
/usr/share/openstack-puppet/modules/nova/manifests/params.pp 112
<        'Fedora', 'RedHat': {
<          $special_service_provider = undef
<        }
<        'RedHat': {
<          if ($::operatingsystemrelease < 7) {
>        'Fedora', 'RedHat', 'CentOS': {
>          $special_service_provider = undef
>        }
>        'RedHat', 'CentOS': {
>          if ($::operatingsystemmajrelease < 7) {
/usr/share/openstack-puppet/modules/apache/manifests/version.pp line 8
<      if ($::operatingsystem == 'Fedora' and $::operatingsystemrelease >= 18) or ($::operatingsystem != 'Fedora' and $::operatingsystemrelease >= 7) {
>      if ($::operatingsystem == 'Fedora' and $::operatingsystemrelease >= 18) or ($::operatingsystem != 'Fedora' and $::operatingsystemmajrelease >= 7) {