Conditionalize syslinux requirement

A non-bios architecture will not have a syslinux package and
therefore cannot assume that it must be installed.

Change-Id: I02e2cb556efe94c68f63e1b919b66cc1a5b9e5b1

manifests/pxe.pp

@@ -36,6 +36,7 @@
 #
 # [*syslinux_path*]
 #   (optional) Path to directory containing syslinux files.
+#   Setting this to False will skip syslinux related resources.
 #   Defaults to '$::ironic::params::syslinux_path'
 #
 # [*syslinux_files*]
@@ -115,16 +116,18 @@ class ironic::pxe (
     content => "r ^([^/]) ${tftp_root_real}/\\1",
   }
 
-  ensure_resource( 'package', 'syslinux', {
-    ensure => $package_ensure,
-    name   => $::ironic::params::syslinux_package,
-    tag    => ['openstack', 'ironic-ipxe', 'ironic-support-package'],
-  })
+  if $syslinux_path {
+    ensure_resource( 'package', 'syslinux', {
+      ensure => $package_ensure,
+      name   => $::ironic::params::syslinux_package,
+      tag    => ['openstack', 'ironic-ipxe', 'ironic-support-package'],
+    })
 
-  ironic::pxe::tftpboot_file { $syslinux_files:
-    source_directory      => $syslinux_path,
-    destination_directory => $tftp_root_real,
-    require               => Anchor['ironic-inspector::install::end'],
+    ironic::pxe::tftpboot_file { $syslinux_files:
+      source_directory      => $syslinux_path,
+      destination_directory => $tftp_root_real,
+      require               => Anchor['ironic-inspector::install::end'],
+    }
   }
 
   ensure_resource( 'package', 'ipxe', {

releasenotes/notes/conditionalize-syslinux-install-89865f7320f94d88.yaml

@@ -0,0 +1,4 @@
+---
+features:
+  - Allow skipping installation of syslinux. UEFI exclusive archiectures do
+    not have syslinux support.

spec/classes/ironic_pxe_spec.rb

@@ -120,6 +120,19 @@ describe 'ironic::pxe' do
         )
       end
     end
+    context 'when excluding syslinux' do
+      before :each do
+        params.merge!(
+          :syslinux_path => false,
+        )
+      end
+      it 'should not contain package syslinux' do
+        is_expected.not_to contain_package('syslinux')
+      end
+      it 'should not contain tftpboot syslinux file' do
+        is_expected.not_to contain_file('/tftpboot/pxelinux.0')
+      end
+    end
   end
 
   on_supported_os({