Validate if service has duplicate targetPort

pkg/api/validation/validation.go

@@ -2865,6 +2865,22 @@ func ValidateService(service *api.Service) field.ErrorList {
 		nodePorts[key] = true
 	}
 
+	// Check for duplicate TargetPort
+	portsPath = specPath.Child("ports")
+	targetPorts := make(map[api.ServicePort]bool)
+	for i, port := range service.Spec.Ports {
+		if (port.TargetPort.Type == intstr.Int && port.TargetPort.IntVal == 0) || (port.TargetPort.Type == intstr.String && port.TargetPort.StrVal == "") {
+			continue
+		}
+		portPath := portsPath.Index(i)
+		key := api.ServicePort{Protocol: port.Protocol, TargetPort: port.TargetPort}
+		_, found := targetPorts[key]
+		if found {
+			allErrs = append(allErrs, field.Duplicate(portPath.Child("targetPort"), port.TargetPort))
+		}
+		targetPorts[key] = true
+	}
+
 	// Validate SourceRange field and annotation
 	_, ok := service.Annotations[api.AnnotationLoadBalancerSourceRangesKey]
 	if len(service.Spec.LoadBalancerSourceRanges) > 0 || ok {

pkg/api/validation/validation_test.go

@@ -6034,6 +6034,42 @@ func TestValidateService(t *testing.T) {
 			numErrs: 0,
 		},
 		{
+			name: "invalid duplicate targetports (number with same protocol)",
+			tweakSvc: func(s *api.Service) {
+				s.Spec.Type = api.ServiceTypeClusterIP
+				s.Spec.Ports = append(s.Spec.Ports, api.ServicePort{Name: "q", Port: 1, Protocol: "TCP", TargetPort: intstr.FromInt(8080)})
+				s.Spec.Ports = append(s.Spec.Ports, api.ServicePort{Name: "r", Port: 2, Protocol: "TCP", TargetPort: intstr.FromInt(8080)})
+			},
+			numErrs: 1,
+		},
+		{
+			name: "invalid duplicate targetports (name with same protocol)",
+			tweakSvc: func(s *api.Service) {
+				s.Spec.Type = api.ServiceTypeClusterIP
+				s.Spec.Ports = append(s.Spec.Ports, api.ServicePort{Name: "q", Port: 1, Protocol: "TCP", TargetPort: intstr.FromString("http")})
+				s.Spec.Ports = append(s.Spec.Ports, api.ServicePort{Name: "r", Port: 2, Protocol: "TCP", TargetPort: intstr.FromString("http")})
+			},
+			numErrs: 1,
+		},
+		{
+			name: "valid duplicate targetports (number with different protocols)",
+			tweakSvc: func(s *api.Service) {
+				s.Spec.Type = api.ServiceTypeClusterIP
+				s.Spec.Ports = append(s.Spec.Ports, api.ServicePort{Name: "q", Port: 1, Protocol: "TCP", TargetPort: intstr.FromInt(8080)})
+				s.Spec.Ports = append(s.Spec.Ports, api.ServicePort{Name: "r", Port: 2, Protocol: "UDP", TargetPort: intstr.FromInt(8080)})
+			},
+			numErrs: 0,
+		},
+		{
+			name: "valid duplicate targetports (name with different protocols)",
+			tweakSvc: func(s *api.Service) {
+				s.Spec.Type = api.ServiceTypeClusterIP
+				s.Spec.Ports = append(s.Spec.Ports, api.ServicePort{Name: "q", Port: 1, Protocol: "TCP", TargetPort: intstr.FromString("http")})
+				s.Spec.Ports = append(s.Spec.Ports, api.ServicePort{Name: "r", Port: 2, Protocol: "UDP", TargetPort: intstr.FromString("http")})
+			},
+			numErrs: 0,
+		},
+		{
 			name: "valid type - cluster",
 			tweakSvc: func(s *api.Service) {
 				s.Spec.Type = api.ServiceTypeClusterIP