fix(istio): support for ExternalIPs in Istio resources

✨ Add support for ExternalIPs in Istio Gateway and VirtualService
ℹ️ This commit extends Istio Gateway and VirtualService resources
to support ExternalIPs. The changes include:
- Checking if service has ExternalIPs defined
- If yes, adding them to the list of targets
- If not, continuing with the existing process

👌 Now you can have your Istio resources use `externalIPs` too! 🎉

Not to be `ip`-percritical, but don't we all love an `ip`grade! 🎈

Signed-off-by: Karsten Siemer <karsten.siemer@sda.se>

source/istio_gateway.go

@@ -289,6 +289,11 @@ func (sc *gatewaySource) targetsFromGateway(ctx context.Context, gateway *networ
 			continue
 		}
 
+		if len(service.Spec.ExternalIPs) > 0 {
+			targets = append(targets, service.Spec.ExternalIPs...)
+			continue
+		}
+
 		for _, lb := range service.Status.LoadBalancer.Ingress {
 			if lb.IP != "" {
 				targets = append(targets, lb.IP)

source/istio_gateway_test.go

@@ -337,8 +337,9 @@ func testEndpointsFromGatewayConfig(t *testing.T) {
 			title: "no rule.host",
 			lbServices: []fakeIngressGatewayService{
 				{
-					ips:       []string{"8.8.8.8", "127.0.0.1"},
+					ips:         []string{"8.8.8.8", "127.0.0.1"},
-					hostnames: []string{"elb.com", "alb.com"},
+					hostnames:   []string{"elb.com", "alb.com"},
+					externalIPs: []string{"1.1.1.1", "2.2.2.2"},
 				},
 			},
 			config: fakeGatewayConfig{
@@ -350,8 +351,9 @@ func testEndpointsFromGatewayConfig(t *testing.T) {
 			title: "one empty rule.host",
 			lbServices: []fakeIngressGatewayService{
 				{
-					ips:       []string{"8.8.8.8", "127.0.0.1"},
+					ips:         []string{"8.8.8.8", "127.0.0.1"},
-					hostnames: []string{"elb.com", "alb.com"},
+					hostnames:   []string{"elb.com", "alb.com"},
+					externalIPs: []string{"1.1.1.1", "2.2.2.2"},
 				},
 			},
 			config: fakeGatewayConfig{
@@ -447,6 +449,48 @@ func testEndpointsFromGatewayConfig(t *testing.T) {
 				},
 			},
 		},
+		{
+			title: "one rule.host one lb.externalIP",
+			lbServices: []fakeIngressGatewayService{
+				{
+					externalIPs: []string{"8.8.8.8"},
+				},
+			},
+			config: fakeGatewayConfig{
+				dnsnames: [][]string{
+					{"foo.bar"},
+				},
+			},
+			expected: []*endpoint.Endpoint{
+				{
+					DNSName:    "foo.bar",
+					RecordType: endpoint.RecordTypeA,
+					Targets:    endpoint.Targets{"8.8.8.8"},
+				},
+			},
+		},
+		{
+			title: "one rule.host two lb.IP, two lb.Hostname and two lb.externalIP",
+			lbServices: []fakeIngressGatewayService{
+				{
+					ips:         []string{"8.8.8.8", "127.0.0.1"},
+					hostnames:   []string{"elb.com", "alb.com"},
+					externalIPs: []string{"1.1.1.1", "2.2.2.2"},
+				},
+			},
+			config: fakeGatewayConfig{
+				dnsnames: [][]string{
+					{"foo.bar"},
+				},
+			},
+			expected: []*endpoint.Endpoint{
+				{
+					DNSName:    "foo.bar",
+					RecordType: endpoint.RecordTypeA,
+					Targets:    endpoint.Targets{"1.1.1.1", "2.2.2.2"},
+				},
+			},
+		},
 	} {
 		ti := ti
 		t.Run(ti.title, func(t *testing.T) {
@@ -1521,11 +1565,12 @@ func newTestGatewaySource(loadBalancerList []fakeIngressGatewayService, ingressL
 }
 
 type fakeIngressGatewayService struct {
-	ips       []string
+	ips         []string
-	hostnames []string
+	hostnames   []string
-	namespace string
+	namespace   string
-	name      string
+	name        string
-	selector  map[string]string
+	selector    map[string]string
+	externalIPs []string
 }
 
 func (ig fakeIngressGatewayService) Service() *v1.Service {
@@ -1540,7 +1585,8 @@ func (ig fakeIngressGatewayService) Service() *v1.Service {
 			},
 		},
 		Spec: v1.ServiceSpec{
-			Selector: ig.selector,
+			Selector:    ig.selector,
+			ExternalIPs: ig.externalIPs,
 		},
 	}
 

source/istio_virtualservice.go

@@ -470,6 +470,11 @@ func (sc *virtualServiceSource) targetsFromGateway(ctx context.Context, gateway
 			continue
 		}
 
+		if len(service.Spec.ExternalIPs) > 0 {
+			targets = append(targets, service.Spec.ExternalIPs...)
+			continue
+		}
+
 		for _, lb := range service.Status.LoadBalancer.Ingress {
 			if lb.IP != "" {
 				targets = append(targets, lb.IP)

source/istio_virtualservice_test.go

@@ -450,6 +450,29 @@ func testEndpointsFromVirtualServiceConfig(t *testing.T) {
 				},
 			},
 		},
+		{
+			title: "one rule.host one lb.externalIPs",
+			lbServices: []fakeIngressGatewayService{
+				{
+					externalIPs: []string{"8.8.8.8"},
+				},
+			},
+			gwconfig: fakeGatewayConfig{
+				name:     "mygw",
+				dnsnames: [][]string{{"*"}},
+			},
+			vsconfig: fakeVirtualServiceConfig{
+				gateways: []string{"mygw"},
+				dnsnames: []string{"foo.bar"},
+			},
+			expected: []*endpoint.Endpoint{
+				{
+					DNSName:    "foo.bar",
+					RecordType: endpoint.RecordTypeA,
+					Targets:    endpoint.Targets{"8.8.8.8"},
+				},
+			},
+		},
 		{
 			title: "one rule.host two lb.IP and two lb.Hostname",
 			lbServices: []fakeIngressGatewayService{
@@ -479,12 +502,38 @@ func testEndpointsFromVirtualServiceConfig(t *testing.T) {
 				},
 			},
 		},
+		{
+			title: "one rule.host two lb.IP and two lb.Hostname and two lb.externalIPs",
+			lbServices: []fakeIngressGatewayService{
+				{
+					ips:         []string{"8.8.8.8", "127.0.0.1"},
+					hostnames:   []string{"elb.com", "alb.com"},
+					externalIPs: []string{"1.1.1.1", "2.2.2.2"},
+				},
+			},
+			gwconfig: fakeGatewayConfig{
+				name:     "mygw",
+				dnsnames: [][]string{{"*"}},
+			},
+			vsconfig: fakeVirtualServiceConfig{
+				gateways: []string{"mygw"},
+				dnsnames: []string{"foo.bar"},
+			},
+			expected: []*endpoint.Endpoint{
+				{
+					DNSName:    "foo.bar",
+					RecordType: endpoint.RecordTypeA,
+					Targets:    endpoint.Targets{"1.1.1.1", "2.2.2.2"},
+				},
+			},
+		},
 		{
 			title: "no rule.host",
 			lbServices: []fakeIngressGatewayService{
 				{
-					ips:       []string{"8.8.8.8", "127.0.0.1"},
+					ips:         []string{"8.8.8.8", "127.0.0.1"},
-					hostnames: []string{"elb.com", "alb.com"},
+					hostnames:   []string{"elb.com", "alb.com"},
+					externalIPs: []string{"1.1.1.1", "2.2.2.2"},
 				},
 			},
 			gwconfig: fakeGatewayConfig{
@@ -501,8 +550,9 @@ func testEndpointsFromVirtualServiceConfig(t *testing.T) {
 			title: "no rule.gateway",
 			lbServices: []fakeIngressGatewayService{
 				{
-					ips:       []string{"8.8.8.8", "127.0.0.1"},
+					ips:         []string{"8.8.8.8", "127.0.0.1"},
-					hostnames: []string{"elb.com", "alb.com"},
+					hostnames:   []string{"elb.com", "alb.com"},
+					externalIPs: []string{"1.1.1.1", "2.2.2.2"},
 				},
 			},
 			gwconfig: fakeGatewayConfig{
@@ -519,8 +569,9 @@ func testEndpointsFromVirtualServiceConfig(t *testing.T) {
 			title: "one empty rule.host",
 			lbServices: []fakeIngressGatewayService{
 				{
-					ips:       []string{"8.8.8.8", "127.0.0.1"},
+					ips:         []string{"8.8.8.8", "127.0.0.1"},
-					hostnames: []string{"elb.com", "alb.com"},
+					hostnames:   []string{"elb.com", "alb.com"},
+					externalIPs: []string{"1.1.1.1", "2.2.2.2"},
 				},
 			},
 			gwconfig: fakeGatewayConfig{
@@ -844,6 +895,42 @@ func testVirtualServiceEndpoints(t *testing.T) {
 				},
 			},
 		},
+		{
+			title: "one virtualservice with two gateways, one ingressgateway loadbalancer service with externalIPs",
+			lbServices: []fakeIngressGatewayService{
+				{
+					namespace:   namespace,
+					externalIPs: []string{"8.8.8.8"},
+				},
+			},
+			gwConfigs: []fakeGatewayConfig{
+				{
+					name:      "gw1",
+					namespace: namespace,
+					dnsnames:  [][]string{{"*"}},
+				},
+				{
+					name:      "gw2",
+					namespace: namespace,
+					dnsnames:  [][]string{{"*"}},
+				},
+			},
+			vsConfigs: []fakeVirtualServiceConfig{
+				{
+					name:      "vs",
+					namespace: namespace,
+					gateways:  []string{"gw1", "gw2"},
+					dnsnames:  []string{"example.org"},
+				},
+			},
+			expected: []*endpoint.Endpoint{
+				{
+					DNSName:    "example.org",
+					RecordType: endpoint.RecordTypeA,
+					Targets:    endpoint.Targets{"8.8.8.8"},
+				},
+			},
+		},
 		{
 			title: "two simple virtualservices on different namespaces with the same target gateway, one ingressgateway loadbalancer service",
 			lbServices: []fakeIngressGatewayService{
@@ -941,6 +1028,44 @@ func testVirtualServiceEndpoints(t *testing.T) {
 				},
 			},
 		},
+		{
+			title:           "two simple virtualservices with one gateway on different namespaces and a target namespace, one ingressgateway loadbalancer service with externalIPs",
+			targetNamespace: "testing1",
+			lbServices: []fakeIngressGatewayService{
+				{
+					externalIPs: []string{"8.8.8.8"},
+					namespace:   "testing1",
+				},
+			},
+			gwConfigs: []fakeGatewayConfig{
+				{
+					name:      "fake1",
+					namespace: "testing1",
+					dnsnames:  [][]string{{"*"}},
+				},
+			},
+			vsConfigs: []fakeVirtualServiceConfig{
+				{
+					name:      "vs1",
+					namespace: "testing1",
+					gateways:  []string{"testing1/fake1"},
+					dnsnames:  []string{"example.org"},
+				},
+				{
+					name:      "vs2",
+					namespace: "testing2",
+					gateways:  []string{"testing1/fake1"},
+					dnsnames:  []string{"new.org"},
+				},
+			},
+			expected: []*endpoint.Endpoint{
+				{
+					DNSName:    "example.org",
+					RecordType: endpoint.RecordTypeA,
+					Targets:    endpoint.Targets{"8.8.8.8"},
+				},
+			},
+		},
 		{
 			title:           "two simple virtualservices with one gateway on different namespaces and a target namespace, one ingress",
 			targetNamespace: "testing1",