Fix the subnet dhcp enable/disable param

neutron subnet-create/update use --enable-dhcp and --disable-dhcp
to manage the dhcp of the subnet

Change-Id: I4c19a770adba2c9eb601e4f389964d3da49cc93e

lib/puppet/provider/neutron_subnet/neutron.rb

@@ -101,8 +101,10 @@ Puppet::Type.type(:neutron_subnet).provide(
       end
     end
 
-    if @resource[:enable_dhcp]
-      opts << "--enable-dhcp=#{@resource[:enable_dhcp]}"
+    if @resource[:enable_dhcp] == 'False'
+      opts << "--disable-dhcp"
+    else
+      opts << "--enable-dhcp"
     end
 
     if @resource[:allocation_pools]
@@ -175,7 +177,11 @@ Puppet::Type.type(:neutron_subnet).provide(
   end
 
   def enable_dhcp=(value)
-    auth_neutron('subnet-update', "--enable-dhcp=#{value}", name)
+    if value == 'False'
+      auth_neutron('subnet-update', "--disable-dhcp", name)
+    else
+      auth_neutron('subnet-update', "--enable-dhcp", name)
+    end
   end
 
   def dns_nameservers=(values)

spec/unit/provider/neutron_subnet/neutron_spec.rb

@@ -51,7 +51,7 @@ describe provider_class do
 
     it 'should call subnet-update to change enable_dhcp' do
       provider.expects(:auth_neutron).with('subnet-update',
-                                           '--enable-dhcp=True',
+                                           '--enable-dhcp',
                                            subnet_name)
       provider.enable_dhcp=('True')
     end
@@ -84,4 +84,24 @@ describe provider_class do
     end
   end
 
+  describe 'when updating a subnet (reverse)' do
+    let :subnet_attrs_mod do
+      subnet_attrs.merge!({:enable_dhcp => 'True'})
+    end
+    let :resource do
+      Puppet::Type::Neutron_subnet.new(subnet_attrs_mod)
+    end
+
+    let :provider do
+      provider_class.new(resource)
+    end
+
+
+    it 'should call subnet-update to change enable_dhcp' do
+      provider.expects(:auth_neutron).with('subnet-update',
+                                           '--disable-dhcp',
+                                           subnet_name)
+      provider.enable_dhcp=('False')
+    end
+  end
 end