Support canary weight for external name service

old/provider/kubernetes/kubernetes.go

@@ -357,15 +357,16 @@ func (p *Provider) loadIngresses(k8sClient Client) (*types.Configuration, error)
 							continue
 						}
 
-						if service.Spec.Type == "ExternalName" {
+						// We have to treat external-name service differently here b/c it doesn't have any endpoints
+						if service.Spec.Type == corev1.ServiceTypeExternalName {
 							url := protocol + "://" + service.Spec.ExternalName
 							if port.Port != 443 && port.Port != 80 {
 								url = fmt.Sprintf("%s:%d", url, port.Port)
 							}
-
+							externalNameServiceWeight := weightAllocator.getWeight(r.Host, pa.Path, pa.Backend.ServiceName)
 							templateObjects.Backends[baseName].Servers[url] = types.Server{
 								URL:    url,
-								Weight: label.DefaultWeight,
+								Weight: externalNameServiceWeight,
 							}
 						} else {
 							endpoints, exists, err := k8sClient.GetEndpoints(service.Namespace, service.Name)

old/provider/kubernetes/kubernetes_test.go

@@ -3232,6 +3232,7 @@ func TestPercentageWeightServiceAnnotation(t *testing.T) {
 		buildIngress(
 			iAnnotation(annotationKubernetesServiceWeights, `
 service1: 10%
+service3: 20%
 `),
 			iNamespace("testing"),
 			iRules(
@@ -3240,6 +3241,7 @@ service1: 10%
 					iPaths(
 						onePath(iPath("/foo"), iBackend("service1", intstr.FromString("8080"))),
 						onePath(iPath("/foo"), iBackend("service2", intstr.FromString("7070"))),
+						onePath(iPath("/foo"), iBackend("service3", intstr.FromString("9090"))),
 						onePath(iPath("/bar"), iBackend("service2", intstr.FromString("7070"))),
 					)),
 			),
@@ -3264,6 +3266,16 @@ service1: 10%
 				sPorts(sPort(7070, "")),
 			),
 		),
+		buildService(
+			sName("service3"),
+			sNamespace("testing"),
+			sUID("1"),
+			sSpec(
+				sType(corev1.ServiceTypeExternalName),
+				sExternalName("example.com"),
+				sPorts(sPort(9090, "")),
+			),
+		),
 	}
 
 	endpoints := []*corev1.Endpoints{
@@ -3311,8 +3323,9 @@ service1: 10%
 				servers(
 					server("http://10.10.0.1:8080", weight(int(newPercentageValueFromFloat64(0.05)))),
 					server("http://10.10.0.2:8080", weight(int(newPercentageValueFromFloat64(0.05)))),
-					server("http://10.10.0.3:7070", weight(int(newPercentageValueFromFloat64(0.45)))),
+					server("http://10.10.0.3:7070", weight(int(newPercentageValueFromFloat64(0.35)))),
-					server("http://10.10.0.4:7070", weight(int(newPercentageValueFromFloat64(0.45)))),
+					server("http://10.10.0.4:7070", weight(int(newPercentageValueFromFloat64(0.35)))),
+					server("http://example.com:9090", weight(int(newPercentageValueFromFloat64(0.2)))),
 				),
 				lbMethod("wrr"),
 			),

old/provider/kubernetes/weight_allocator.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/containous/traefik/old/provider/label"
 	"gopkg.in/yaml.v2"
+	corev1 "k8s.io/api/core/v1"
 	extensionsv1beta1 "k8s.io/api/extensions/v1beta1"
 )
 
@@ -165,6 +166,23 @@ func getServiceInstanceCounts(ingress *extensionsv1beta1.Ingress, client Client)
 
 	for _, rule := range ingress.Spec.Rules {
 		for _, pa := range rule.HTTP.Paths {
+			svc, exists, err := client.GetService(ingress.Namespace, pa.Backend.ServiceName)
+			if err != nil {
+				return nil, fmt.Errorf("failed to get service %s/%s: %v", ingress.Namespace, pa.Backend.ServiceName, err)
+			}
+			if !exists {
+				return nil, fmt.Errorf("service not found for %s/%s", ingress.Namespace, pa.Backend.ServiceName)
+			}
+			if svc.Spec.Type == corev1.ServiceTypeExternalName {
+				// external-name service has only one instance b/c it will actually be interpreted as a DNS record
+				// instead of real server.
+				serviceInstanceCounts[ingressService{
+					host:    rule.Host,
+					path:    pa.Path,
+					service: pa.Backend.ServiceName,
+				}] = 1
+				continue
+			}
 			count := 0
 			endpoints, exists, err := client.GetEndpoints(ingress.Namespace, pa.Backend.ServiceName)
 			if err != nil {

old/provider/kubernetes/weight_allocator_test.go

@@ -169,6 +169,24 @@ service1: 1000%
 
 func TestComputeServiceWeights(t *testing.T) {
 	client := clientMock{
+		services: []*corev1.Service{
+			buildService(
+				sName("service1"),
+				sNamespace("testing"),
+			),
+			buildService(
+				sName("service2"),
+				sNamespace("testing"),
+			),
+			buildService(
+				sName("service3"),
+				sNamespace("testing"),
+			),
+			buildService(
+				sName("service4"),
+				sNamespace("testing"),
+			),
+		},
 		endpoints: []*corev1.Endpoints{
 			buildEndpoint(
 				eNamespace("testing"),
@@ -446,8 +464,12 @@ service2: 80%
 			if test.expectError {
 				require.Error(t, err)
 			} else {
-				for ingSvc, percentage := range test.expectedWeights {
+				if err != nil {
-					assert.Equal(t, int(percentage), weightAllocator.getWeight(ingSvc.host, ingSvc.path, ingSvc.service))
+					t.Errorf("%v failed: %v", test.desc, err)
+				} else {
+					for ingSvc, percentage := range test.expectedWeights {
+						assert.Equal(t, int(percentage), weightAllocator.getWeight(ingSvc.host, ingSvc.path, ingSvc.service))
+					}
 				}
 			}
 		})