Add OverlappingTLSConfig condition

Author: ciarams87

internal/controller/state/conditions/conditions.go

@@ -29,6 +29,11 @@ const (
 	ListenerMessageFailedNginxReload = "The Listener is not programmed due to a failure to " +
 		"reload nginx with the configuration"
 
+	// ListenerMessageOverlappingHostnames is a message used with the "OverlappingTLSConfig" condition when the
+	// condition is true due to overlapping hostnames.
+	ListenerMessageOverlappingHostnames = "Listener hostname overlaps with hostname(s) of other Listener(s) " +
+		"on the same port"
+
 	// RouteReasonBackendRefUnsupportedValue is used with the "ResolvedRefs" condition when one of the
 	// Route rules has a backendRef with an unsupported value.
 	RouteReasonBackendRefUnsupportedValue v1.RouteConditionReason = "UnsupportedValue"
@@ -501,13 +506,32 @@ func NewRouteResolvedRefsInvalidFilter(msg string) Condition {
 }
 
 // NewDefaultListenerConditions returns the default Conditions that must be present in the status of a Listener.
-func NewDefaultListenerConditions() []Condition {
-	return []Condition{
+// If existingConditions contains conflict-related conditions (like OverlappingTLSConfig or Conflicted),
+// the NoConflicts condition is excluded to avoid conflicting condition states.
+func NewDefaultListenerConditions(existingConditions []Condition) []Condition {
+	defaultConds := []Condition{
 		NewListenerAccepted(),
 		NewListenerProgrammed(),
 		NewListenerResolvedRefs(),
-		NewListenerNoConflicts(),
 	}
+
+	// Only add NoConflicts condition if there are no existing conflict-related conditions
+	if !hasConflictConditions(existingConditions) {
+		defaultConds = append(defaultConds, NewListenerNoConflicts())
+	}
+
+	return defaultConds
+}
+
+// hasConflictConditions checks if the listener has any conflict-related conditions.
+func hasConflictConditions(conditions []Condition) bool {
+	for _, cond := range conditions {
+		if cond.Type == string(v1.ListenerConditionConflicted) ||
+			cond.Type == string(v1.ListenerConditionOverlappingTLSConfig) {
+			return true
+		}
+	}
+	return false
 }
 
 // NewListenerAccepted returns a Condition that indicates that the Listener is accepted.
@@ -681,6 +705,17 @@ func NewListenerRefNotPermitted(msg string) []Condition {
 	}
 }
 
+// NewListenerOverlappingTLSConfig returns a Condition that indicates overlapping TLS configuration
+// between Listeners on the same port.
+func NewListenerOverlappingTLSConfig(reason v1.ListenerConditionReason, msg string) Condition {
+	return Condition{
+		Type:    string(v1.ListenerConditionOverlappingTLSConfig),
+		Status:  metav1.ConditionTrue,
+		Reason:  string(reason),
+		Message: msg,
+	}
+}
+
 // NewGatewayClassResolvedRefs returns a Condition that indicates that the parametersRef
 // on the GatewayClass is resolved.
 func NewGatewayClassResolvedRefs() Condition {

internal/controller/state/graph/gateway_listener.go

@@ -89,6 +89,7 @@ func newListenerConfiguratorFactory(
 	protectedPorts ProtectedPorts,
 ) *listenerConfiguratorFactory {
 	sharedPortConflictResolver := createPortConflictResolver()
+	sharedOverlappingTLSConfigResolver := createOverlappingTLSConfigResolver()
 
 	return &listenerConfiguratorFactory{
 		unsupportedProtocol: &listenerConfigurator{
@@ -123,6 +124,7 @@ func newListenerConfiguratorFactory(
 			},
 			conflictResolvers: []listenerConflictResolver{
 				sharedPortConflictResolver,
+				sharedOverlappingTLSConfigResolver,
 			},
 			externalReferenceResolvers: []listenerExternalReferenceResolver{
 				createExternalReferencesForTLSSecretsResolver(gw.Namespace, secretResolver, refGrantResolver),
@@ -137,6 +139,7 @@ func newListenerConfiguratorFactory(
 			},
 			conflictResolvers: []listenerConflictResolver{
 				sharedPortConflictResolver,
+				sharedOverlappingTLSConfigResolver,
 			},
 			externalReferenceResolvers: []listenerExternalReferenceResolver{},
 		},
@@ -591,3 +594,38 @@ func haveOverlap(hostname1, hostname2 *v1.Hostname) bool {
 	}
 	return matchesWildcard(h1, h2)
 }
+
+func createOverlappingTLSConfigResolver() listenerConflictResolver {
+	listenersByPort := make(map[v1.PortNumber][]*Listener)
+
+	return func(l *Listener) {
+		port := l.Source.Port
+
+		// Only check TLS-enabled listeners (HTTPS/TLS)
+		if l.Source.Protocol != v1.HTTPSProtocolType && l.Source.Protocol != v1.TLSProtocolType {
+			return
+		}
+
+		// Check for overlaps with existing listeners on this port
+		for _, existingListener := range listenersByPort[port] {
+			// Only check against other TLS-enabled listeners
+			if existingListener.Source.Protocol != v1.HTTPSProtocolType &&
+				existingListener.Source.Protocol != v1.TLSProtocolType {
+				continue
+			}
+
+			// Check for hostname overlap
+			if haveOverlap(l.Source.Hostname, existingListener.Source.Hostname) {
+				// Set condition on both listeners
+				cond := conditions.NewListenerOverlappingTLSConfig(
+					v1.ListenerReasonOverlappingHostnames,
+					conditions.ListenerMessageOverlappingHostnames,
+				)
+				l.Conditions = append(l.Conditions, cond)
+				existingListener.Conditions = append(existingListener.Conditions, cond)
+			}
+		}
+
+		listenersByPort[port] = append(listenersByPort[port], l)
+	}
+}