Add Scheduler validation check for redeclared plugin configs

pkg/scheduler/api/validation/validation.go

@@ -34,10 +34,18 @@ import (
 func ValidatePolicy(policy schedulerapi.Policy) error {
 	var validationErrors []error
 
+	priorities := make(map[string]schedulerapi.PriorityPolicy, len(policy.Priorities))
 	for _, priority := range policy.Priorities {
 		if priority.Weight <= 0 || priority.Weight >= framework.MaxWeight {
 			validationErrors = append(validationErrors, fmt.Errorf("Priority %s should have a positive weight applied to it or it has overflown", priority.Name))
 		}
+
+		validationErrors = append(validationErrors, validatePriorityRedeclared(priorities, priority))
+	}
+
+	predicates := make(map[string]schedulerapi.PredicatePolicy, len(policy.Predicates))
+	for _, predicate := range policy.Predicates {
+		validationErrors = append(validationErrors, validatePredicateRedeclared(predicates, predicate))
 	}
 
 	binders := 0
@@ -66,6 +74,48 @@ func ValidatePolicy(policy schedulerapi.Policy) error {
 	return utilerrors.NewAggregate(validationErrors)
 }
 
+// validatePriorityRedeclared checks if any custom priorities have been declared multiple times in the policy config
+// by examining the specified priority arguments
+func validatePriorityRedeclared(priorities map[string]schedulerapi.PriorityPolicy, priority schedulerapi.PriorityPolicy) error {
+	var priorityType string
+	if priority.Argument != nil {
+		if priority.Argument.LabelPreference != nil {
+			priorityType = "LabelPreference"
+		} else if priority.Argument.RequestedToCapacityRatioArguments != nil {
+			priorityType = "RequestedToCapacityRatioArguments"
+		} else if priority.Argument.ServiceAntiAffinity != nil {
+			priorityType = "ServiceAntiAffinity"
+		} else {
+			return fmt.Errorf("No priority arguments set for priority %s", priority.Name)
+		}
+		if existing, alreadyDeclared := priorities[priorityType]; alreadyDeclared {
+			return fmt.Errorf("Priority %s is redeclared (was %+v)", priority.Name, existing)
+		}
+		priorities[priorityType] = priority
+	}
+	return nil
+}
+
+// validatePredicateRedeclared checks if any custom predicates have been declared multiple times in the policy config
+// by examining the specified predicate arguments
+func validatePredicateRedeclared(predicates map[string]schedulerapi.PredicatePolicy, predicate schedulerapi.PredicatePolicy) error {
+	var predicateType string
+	if predicate.Argument != nil {
+		if predicate.Argument.LabelsPresence != nil {
+			predicateType = "LabelsPresence"
+		} else if predicate.Argument.ServiceAffinity != nil {
+			predicateType = "ServiceAffinity"
+		} else {
+			return fmt.Errorf("No priority arguments set for priority %s", predicate.Name)
+		}
+		if existing, alreadyDeclared := predicates[predicateType]; alreadyDeclared {
+			return fmt.Errorf("Priority %s is redeclared (was %+v)", predicate.Name, existing)
+		}
+		predicates[predicateType] = predicate
+	}
+	return nil
+}
+
 // validateExtendedResourceName checks whether the specified name is a valid
 // extended resource name.
 func validateExtendedResourceName(name v1.ResourceName) []error {