chore: remove deprecated KongIngress functionality

CHANGELOG.md

@@ -85,6 +85,9 @@ Adding a new version? You'll need three changes:
   [#4749](https://github.com/Kong/kubernetes-ingress-controller/pull/4749)
 - Removed Knative support.
   [#4748](https://github.com/Kong/kubernetes-ingress-controller/pull/4748)
+- Removed support for deprecated `KongIngress` fields: `Proxy` and `Route`. Respective
+  `Service` or `Ingress` annotations should be used instead. See [KIC Annotations reference].
+  [#4760](https://github.com/Kong/kubernetes-ingress-controller/pull/4760)
 
 ### Fixed
 
@@ -99,6 +102,8 @@ Adding a new version? You'll need three changes:
   it'll be treated as any other label without a special meaning.
   [#4737](https://github.com/Kong/kubernetes-ingress-controller/pull/4737)
 
+[KIC Annotations reference]: https://docs.konghq.com/kubernetes-ingress-controller/latest/references/annotations/
+
 ## 2.12.0
 
 > Release date: 2023-09-25

internal/admission/handler.go

@@ -310,12 +310,12 @@ func (h RequestHandler) handleKongIngress(_ context.Context, request admissionv1
 	responseBuilder = responseBuilder.Allowed(true)
 
 	if kongIngress.Proxy != nil {
-		const warning = "'proxy' is DEPRECATED. Use Service's annotations instead."
+		const warning = "'proxy' is DEPRECATED. It will have no effect. Use Service's annotations instead."
 		responseBuilder = responseBuilder.WithWarning(warning)
 	}
 
 	if kongIngress.Route != nil {
-		const warning = "'route' is DEPRECATED. Use Ingress' annotations instead."
+		const warning = "'route' is DEPRECATED. It will have no effect. Use Ingress' annotations instead."
 		responseBuilder = responseBuilder.WithWarning(warning)
 	}
 

internal/dataplane/kongstate/kongstate.go

@@ -196,30 +196,11 @@ func (ks *KongState) FillConsumerGroups(_ logrus.FieldLogger, s store.Storer) {
 func (ks *KongState) FillOverrides(log logrus.FieldLogger, s store.Storer) {
 	for i := 0; i < len(ks.Services); i++ {
 		// Services
-		kongIngress, err := getKongIngressForServices(s, ks.Services[i].K8sServices)
-		if err != nil {
-			log.WithError(err).
-				Errorf("failed to fetch KongIngress resource for Services %s",
-					PrettyPrintServiceList(ks.Services[i].K8sServices),
-				)
-			continue
-		}
-
-		for _, svc := range ks.Services[i].K8sServices {
-			ks.Services[i].override(log, kongIngress, svc)
-		}
+		ks.Services[i].override()
 
 		// Routes
 		for j := 0; j < len(ks.Services[i].Routes); j++ {
-			kongIngress, err := getKongIngressFromObjectMeta(s, ks.Services[i].Routes[j].Ingress)
-			if err != nil {
-				log.WithFields(logrus.Fields{
-					"resource_name":      ks.Services[i].Routes[j].Ingress.Name,
-					"resource_namespace": ks.Services[i].Routes[j].Ingress.Namespace,
-				}).WithError(err).Errorf("failed to fetch KongIngress resource")
-			}
-
-			ks.Services[i].Routes[j].override(log, kongIngress)
+			ks.Services[i].Routes[j].override(log)
 		}
 	}
 

internal/dataplane/kongstate/route.go

@@ -7,11 +7,9 @@ import (
 
 	"github.com/kong/go-kong/kong"
 	"github.com/sirupsen/logrus"
-	gatewayv1alpha2 "sigs.k8s.io/gateway-api/apis/v1alpha2"
 
 	"github.com/kong/kubernetes-ingress-controller/v2/internal/annotations"
 	"github.com/kong/kubernetes-ingress-controller/v2/internal/util"
-	kongv1 "github.com/kong/kubernetes-ingress-controller/v2/pkg/apis/configuration/v1"
 )
 
 // Route represents a Kong Route and holds a reference to the Ingress
@@ -250,106 +248,15 @@ func (r *Route) overrideByAnnotation(log logrus.FieldLogger) {
 }
 
 // override sets Route fields by KongIngress first, then by annotation.
-func (r *Route) override(log logrus.FieldLogger, kongIngress *kongv1.KongIngress) {
+func (r *Route) override(log logrus.FieldLogger) {
 	if r == nil {
 		return
 	}
 
-	// Check if we're trying to get KongIngress configuration based on an annotation
-	// on Gateway API object (this would most likely happen for *Route objects but
-	// log a warning for all other Gateway API objects as well since that also should
-	// not happen) and if that's the case then skip it since those should not be
-	// affected by said annotation.
-	if gvk := r.Ingress.GroupVersionKind; gvk.Group == gatewayv1alpha2.GroupName && kongIngress != nil {
-		log.WithFields(logrus.Fields{
-			"resource_name":      r.Ingress.Name,
-			"resource_namespace": r.Ingress.Namespace,
-			"resource_kind":      gvk.Kind,
-		}).Warn("KongIngress annotation is not allowed on Gateway API objects.")
-		return
-	}
-
-	r.overrideByKongIngress(log, kongIngress)
 	r.overrideByAnnotation(log)
 	r.normalizeProtocols()
 }
 
-// overrideByKongIngress sets Route fields by KongIngress.
-func (r *Route) overrideByKongIngress(log logrus.FieldLogger, kongIngress *kongv1.KongIngress) {
-	// disable overriding routes by KongIngress if expression routes is enabled.
-	if r.ExpressionRoutes {
-		return
-	}
-
-	if kongIngress == nil || kongIngress.Route == nil {
-		return
-	}
-
-	ir := kongIngress.Route
-	if len(ir.Methods) != 0 {
-		invalid := false
-		var methods []*string
-		for _, method := range ir.Methods {
-			sanitizedMethod := strings.TrimSpace(strings.ToUpper(*method))
-			if validMethods.MatchString(sanitizedMethod) {
-				methods = append(methods, kong.String(sanitizedMethod))
-			} else {
-				// if any method is invalid (not an uppercase alpha string),
-				// discard everything
-				log.WithFields(logrus.Fields{
-					"ingress_namespace": r.Ingress.Namespace,
-					"ingress_name":      r.Ingress.Name,
-				}).Errorf("ingress contains invalid method: '%v'", *method)
-				invalid = true
-			}
-		}
-		if !invalid {
-			r.Methods = methods
-		}
-	}
-	if len(ir.Headers) != 0 {
-		r.Headers = ir.Headers
-	}
-	if len(ir.Protocols) != 0 {
-		r.Protocols = protocolPointersToStringPointers(ir.Protocols)
-	}
-	if ir.RegexPriority != nil {
-		r.RegexPriority = kong.Int(*ir.RegexPriority)
-	}
-	if ir.StripPath != nil {
-		r.StripPath = kong.Bool(*ir.StripPath)
-	}
-	if ir.PreserveHost != nil {
-		r.PreserveHost = kong.Bool(*ir.PreserveHost)
-	}
-	if ir.HTTPSRedirectStatusCode != nil {
-		r.HTTPSRedirectStatusCode = kong.Int(*ir.HTTPSRedirectStatusCode)
-	}
-	if ir.PathHandling != nil {
-		r.PathHandling = kong.String(*ir.PathHandling)
-	}
-	if len(ir.SNIs) != 0 {
-		var SNIs []*string
-		for _, unsanitizedSNI := range ir.SNIs {
-			SNI := strings.TrimSpace(*unsanitizedSNI)
-			if validSNIs.MatchString(SNI) {
-				SNIs = append(SNIs, kong.String(SNI))
-			} else {
-				// SNI is not a valid hostname
-				log.WithField("kongroute", r.Name).Errorf("invalid SNI: %v", unsanitizedSNI)
-				return
-			}
-		}
-		r.SNIs = SNIs
-	}
-	if ir.RequestBuffering != nil {
-		r.RequestBuffering = kong.Bool(*ir.RequestBuffering)
-	}
-	if ir.ResponseBuffering != nil {
-		r.ResponseBuffering = kong.Bool(*ir.ResponseBuffering)
-	}
-}
-
 // overrideRequestBuffering ensures defaults for the request_buffering option.
 func (r *Route) overrideRequestBuffering(log logrus.FieldLogger, anns map[string]string) {
 	annotationValue, ok := annotations.ExtractRequestBuffering(anns)