compute: allow more granularity on hypervisor nodes

- Allow to enable / disable RBD storage for:
  * Instances & Volumes
  * Volumes only (instances will be stored locally then)
- Deprecate has_ceph param with backward compatibility
- If RBD backend for instances is enabled on Red Hat, fail with a
  message.

Closes-bug #486
Signed-off-by: Emilien Macchi <emilien.macchi@enovance.com>

manifests/compute/hypervisor.pp

@@ -19,10 +19,14 @@
 #
 # === Parameters:
 #
-# [*has_ceph]
+# [*vm_rbd]
-#   (optional) Enable or not ceph capabilities on compute node.
+#   (optional) Enable or not ceph capabilities on compute node to store
-#   If Ceph is used as a backend for Cinder or Nova, this option should be
+#   nova instances on ceph storage.
-#   set to True.
+#   Default to false.
+#
+# [*volume_rbd]
+#   (optional) Enable or not ceph capabilities on compute node to attach
+#   cinder volumes backend by ceph on nova instances.
 #   Default to false.
 #
 
@@ -37,6 +41,9 @@ class cloud::compute::hypervisor(
   $cinder_rbd_user            = 'cinder',
   $nova_rbd_pool              = 'vms',
   $nova_rbd_secret_uuid       = undef,
+  $vm_rbd                     = false,
+  $volume_rbd                 = false,
+  # DEPRECATED
   $has_ceph                   = false
 ) {
 
@@ -44,6 +51,17 @@ class cloud::compute::hypervisor(
   include 'cloud::telemetry'
   include 'cloud::network'
 
+  # Backward compatibility
+  # if has_ceph was enabled, we consider deployments run Ceph for Nova & Cinder
+  if $has_ceph {
+    warning('has_ceph parameter is deprecated. Please use vm_rbd and volume_rbd parameters.')
+    $vm_rbd_real     = true
+    $volume_rbd_real = true
+  } else {
+    $vm_rbd_real     = $vm_rbd
+    $volume_rbd_real = $volume_rbd
+  }
+
   file{ '/var/lib/nova/.ssh':
     ensure  => directory,
     mode    => '0700',
@@ -103,12 +121,9 @@ Host *
       notify => Service['libvirtd']
     }
     # Nova support for RBD backend is not supported in Red Hat packages
-    if $has_ceph {
+    if $has_ceph or $vm_rbd {
-      warning('Red Hat does not support RBD backend for VMs.')
+      fail('Red Hat does not support RBD backend for VMs.')
     }
-    $has_ceph_real = false
-  } else {
-    $has_ceph_real = $has_ceph
   }
 
   if $::operatingsystem == 'Ubuntu' {
@@ -125,14 +140,23 @@ Host *
 
   class { 'nova::compute::neutron': }
 
-  if $has_ceph_real {
+  if $vm_rbd_real or $volume_rbd_real {
 
-    $libvirt_disk_cachemodes_real = ['network=writeback']
     include 'cloud::storage::rbd'
 
-    class { 'nova::compute::rbd':
+    $libvirt_disk_cachemodes_real = ['network=writeback']
-      libvirt_rbd_user        => $cinder_rbd_user,
+
-      libvirt_images_rbd_pool => $nova_rbd_pool
+    # when nova uses ceph for instances storage
+    if $vm_rbd_real {
+      class { 'nova::compute::rbd':
+        libvirt_rbd_user        => $cinder_rbd_user,
+        libvirt_images_rbd_pool => $nova_rbd_pool
+      }
+    } else {
+      # when nova only needs to attach ceph volumes to instances
+      nova_config {
+        'libvirt/rbd_user': value => $cinder_rbd_user;
+      }
     }
     # we don't want puppet-nova manages keyring
     nova_config {

spec/classes/cloud_compute_hypervisor_spec.rb

@@ -74,6 +74,8 @@ describe 'cloud::compute::hypervisor' do
         :nova_ssh_private_key                 => 'secrete',
         :nova_ssh_public_key                  => 'public',
         :ks_nova_public_proto                 => 'http',
+        :vm_rbd                               => false,
+        :volume_rbd                           => false,
         :ks_nova_public_host                  => '10.0.0.1' }
     end
 
@@ -221,6 +223,7 @@ describe 'cloud::compute::hypervisor' do
 
     it 'should not configure nova-compute for RBD backend' do
       should_not contain_nova_config('libvirt/rbd_user').with('value' => 'cinder')
+      should_not contain_nova_config('libvirt/images_type').with('value' => 'rbd')
     end
 
     it 'configure libvirt driver without disk cachemodes' do
@@ -255,7 +258,73 @@ describe 'cloud::compute::hypervisor' do
       end
     end
 
-    context 'with RBD backend on Debian plaforms' do
+    context 'with RBD backend for instances and volumes on Debian plaforms' do
+      before :each do
+        facts.merge!( :osfamily => 'Debian' )
+        params.merge!(
+          :vm_rbd               => true,
+          :volume_rbd           => true,
+          :cinder_rbd_user      => 'cinder',
+          :nova_rbd_pool        => 'nova',
+          :nova_rbd_secret_uuid => 'secrete' )
+      end
+
+      it 'configure nova-compute to support RBD backend' do
+        should contain_nova_config('libvirt/images_type').with('value' => 'rbd')
+        should contain_nova_config('libvirt/images_rbd_pool').with('value' => 'nova')
+        should contain_nova_config('libvirt/images_rbd_ceph_conf').with('value' => '/etc/ceph/ceph.conf')
+        should contain_nova_config('libvirt/rbd_user').with('value' => 'cinder')
+        should contain_nova_config('libvirt/rbd_secret_uuid').with('value' => 'secrete')
+        should contain_group('cephkeyring').with(:ensure => 'present')
+        should contain_exec('add-nova-to-group').with(
+          :command => 'usermod -a -G cephkeyring nova',
+          :unless  => 'groups nova | grep cephkeyring'
+        )
+      end
+
+      it 'configure libvirt driver' do
+        should contain_class('nova::compute::libvirt').with(
+            :libvirt_type      => 'kvm',
+            :vncserver_listen  => '0.0.0.0',
+            :migration_support => true,
+            :libvirt_disk_cachemodes => ['network=writeback']
+          )
+      end
+    end
+
+    context 'with RBD support only for volumes on Debian plaforms' do
+      before :each do
+        facts.merge!( :osfamily => 'Debian' )
+        params.merge!(
+          :vm_rbd               => false,
+          :volume_rbd           => true,
+          :cinder_rbd_user      => 'cinder',
+          :nova_rbd_secret_uuid => 'secrete' )
+      end
+
+      it 'configure nova-compute to support RBD backend' do
+        should_not contain_nova_config('libvirt/images_type').with('value' => 'rbd')
+        should_not contain_nova_config('libvirt/images_rbd_pool').with('value' => 'nova')
+        should contain_nova_config('libvirt/rbd_user').with('value' => 'cinder')
+        should contain_nova_config('libvirt/rbd_secret_uuid').with('value' => 'secrete')
+        should contain_group('cephkeyring').with(:ensure => 'present')
+        should contain_exec('add-nova-to-group').with(
+          :command => 'usermod -a -G cephkeyring nova',
+          :unless  => 'groups nova | grep cephkeyring'
+        )
+      end
+
+      it 'configure libvirt driver' do
+        should contain_class('nova::compute::libvirt').with(
+            :libvirt_type      => 'kvm',
+            :vncserver_listen  => '0.0.0.0',
+            :migration_support => true,
+            :libvirt_disk_cachemodes => ['network=writeback']
+          )
+      end
+    end
+
+    context 'with RBD backend on Debian plaforms using deprecated parameter' do
       before :each do
         facts.merge!( :osfamily => 'Debian' )
         params.merge!(
@@ -289,6 +358,18 @@ describe 'cloud::compute::hypervisor' do
     end
 
     context 'when trying to enable RBD backend on RedHat plaforms' do
+      before :each do
+        facts.merge!( :operatingsystem => 'RedHat' )
+        params.merge!(
+          :vm_rbd               => true,
+          :cinder_rbd_user      => 'cinder',
+          :nova_rbd_pool        => 'nova',
+          :nova_rbd_secret_uuid => 'secrete' )
+      end
+      it_raises 'a Puppet::Error', /Red Hat does not support RBD backend for VMs./
+    end
+
+    context 'when trying to enable RBD backend with deprecated parameter on RedHat plaforms' do
       before :each do
         facts.merge!( :operatingsystem => 'RedHat' )
         params.merge!(
@@ -297,17 +378,8 @@ describe 'cloud::compute::hypervisor' do
           :nova_rbd_pool        => 'nova',
           :nova_rbd_secret_uuid => 'secrete' )
       end
-
+      it_raises 'a Puppet::Error', /Red Hat does not support RBD backend for VMs./
-      it 'configure libvirt driver without libvirt_disk_cachemodes' do
-        should contain_class('nova::compute::libvirt').with(
-          :libvirt_type      => 'kvm',
-          :vncserver_listen  => '0.0.0.0',
-          :migration_support => true,
-          :libvirt_disk_cachemodes => []
-        )
-      end
     end
-
  end
 
   context 'on Debian platforms' do