Merge pull request #53576 from xiangpengzhao/revert-47284

Automatic merge from submit-queue (batch tested with PRs 54826, 53576, 55591, 54946, 54825). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Revert "Validate if service has duplicate targetPort"

**What this PR does / why we need it**:
Services allow duplicate targetPort. This reverts commit ce54d9072b.

**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes #53526

**Special notes for your reviewer**:
/cc @thockin @jhorwit2 

**Release note**:

```release-note
NONE
```

pkg/apis/core/validation/validation.go

@@ -3188,22 +3188,6 @@ func ValidateService(service *core.Service) field.ErrorList {
 		ports[key] = true
 	}
 
-	// Check for duplicate TargetPort
-	portsPath = specPath.Child("ports")
-	targetPorts := make(map[core.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 := core.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[core.AnnotationLoadBalancerSourceRangesKey]
 	if len(service.Spec.LoadBalancerSourceRanges) > 0 || ok {