Enforce correct value for encapsulation type

The ovn-encap-type option accepts vxlan, geneve and stt. Ensure that
only supported values are given.

Note:
stt is already deprecated and is not quote popular in OpenStack
deployments so is not accepted at this moment.

Change-Id: I9365504a7b444b5f06c44aeda2cbb131f9c8aa0a

manifests/controller.pp

@@ -147,7 +147,7 @@ class ovn::controller(
   String $ovn_remote,
   Stdlib::IP::Address $ovn_encap_ip,
   String $package_ensure                                            = 'present',
-  Variant[String[1], Array[String[1]]] $ovn_encap_type              = 'geneve',
+  Variant[Ovn::EncapType, Array[Ovn::EncapType]] $ovn_encap_type    = 'geneve',
   Optional[Variant[String, Integer]] $ovn_encap_tos                 = undef,
   Ovn::BridgeMappings $ovn_bridge_mappings                          = [],
   Array[String[1]] $bridge_interface_mappings                       = [],

spec/type_aliases/encaptype_spec.rb

@@ -0,0 +1,35 @@
+require 'spec_helper'
+
+describe 'Ovn::EncapType' do
+  describe 'valid types' do
+    context 'with valid types' do
+      [
+        'geneve',
+        'vxlan'
+      ].each do |value|
+        describe value.inspect do
+          it { is_expected.to allow_value(value) }
+        end
+      end
+    end
+  end
+
+  describe 'invalid types' do
+    context 'with garbage inputs' do
+      [
+        '',
+        'vlan',
+        true,
+        false,
+        1,
+        ['vxlan'],
+        {'' => 'vxlan'},
+        {'vxlan' => ''}
+      ].each do |value|
+        describe value.inspect do
+          it { is_expected.not_to allow_value(value) }
+        end
+      end
+    end
+  end
+end

types/encaptype.pp

@@ -0,0 +1 @@
+type Ovn::EncapType = Enum['geneve', 'vxlan']