feat(kuma-cp) add virtual host domain name configurer

pkg/xds/envoy/routes/configurers.go

@@ -17,6 +17,18 @@ func CommonVirtualHost(name string) VirtualHostBuilderOpt {
 	)
 }
 
+func DomainNames(domainNames ...string) VirtualHostBuilderOpt {
+	if len(domainNames) == 0 {
+		return VirtualHostBuilderOptFunc(nil)
+	}
+
+	return AddVirtualHostConfigurer(
+		v3.VirtualHostMustConfigureFunc(func(vh *envoy_route.VirtualHost) {
+			vh.Domains = domainNames
+		}),
+	)
+}
+
 func Routes(routes envoy_common.Routes) VirtualHostBuilderOpt {
 	return AddVirtualHostConfigurer(
 		&v3.RoutesConfigurer{

pkg/xds/envoy/routes/virtual_host_builder.go

@@ -68,7 +68,9 @@ func (c *VirtualHostBuilderConfig) AddV3(configurer v3.VirtualHostConfigurer) {
 type VirtualHostBuilderOptFunc func(config *VirtualHostBuilderConfig)
 
 func (f VirtualHostBuilderOptFunc) ApplyTo(config *VirtualHostBuilderConfig) {
-	f(config)
+	if f != nil {
+		f(config)
+	}
 }
 
 // AddVirtualHostConfigurer production an option that adds the given

pkg/xds/envoy/routes/virtual_host_configurer_test.go

@@ -12,9 +12,10 @@ import (
 
 var _ = Describe("RouteConfigurationVirtualHostConfigurer", func() {
 
+	type Opt = VirtualHostBuilderOpt
 	type testCase struct {
-		virtualHostName string
-		expected        string
+		opts     []Opt
+		expected string
 	}
 
 	Context("V3", func() {
@@ -23,7 +24,7 @@ var _ = Describe("RouteConfigurationVirtualHostConfigurer", func() {
 				// when
 				routeConfiguration, err := NewRouteConfigurationBuilder(envoy.APIV3).
 					Configure(VirtualHost(NewVirtualHostBuilder(envoy.APIV3).
-						Configure(CommonVirtualHost(given.virtualHostName)))).
+						Configure(given.opts...))).
 					Build()
 				// then
 				Expect(err).ToNot(HaveOccurred())
@@ -36,7 +37,32 @@ var _ = Describe("RouteConfigurationVirtualHostConfigurer", func() {
 				Expect(actual).To(MatchYAML(given.expected))
 			},
 			Entry("basic virtual host", testCase{
-				virtualHostName: "backend",
+				opts: []Opt{CommonVirtualHost("backend")},
+				expected: `
+            virtualHosts:
+            - domains:
+              - '*'
+              name: backend
+`,
+			}),
+			Entry("virtual host with domains", testCase{
+				opts: []Opt{
+					CommonVirtualHost("backend"),
+					DomainNames("foo.example.com", "bar.example.com"),
+				},
+				expected: `
+            virtualHosts:
+            - domains:
+              - foo.example.com
+              - bar.example.com
+              name: backend
+`,
+			}),
+			Entry("virtual host with empty domains", testCase{
+				opts: []Opt{
+					CommonVirtualHost("backend"),
+					DomainNames(),
+				},
 				expected: `
             virtualHosts:
             - domains: