From 4386d8ba945df56f463000f4ba23c9aad1ad561c Mon Sep 17 00:00:00 2001
From: David Winiarski <david@adpt.ca>
Date: Mon, 31 Mar 2025 14:02:07 -0600
Subject: [PATCH] only consider accepted gateway routes if the condition
 generation matches the current one

---
 source/gateway.go      | 10 +++---
 source/gateway_test.go | 73 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 78 insertions(+), 5 deletions(-)

diff --git a/source/gateway.go b/source/gateway.go
index 33ef3be3d..d901d7f16 100644
--- a/source/gateway.go
+++ b/source/gateway.go
@@ -293,7 +293,7 @@ func (c *gatewayRouteResolver) resolve(rt gatewayRoute) (map[string]endpoint.Tar
 		return nil, err
 	}
 	hostTargets := make(map[string]endpoint.Targets)
-
+	currentGeneration := rt.Metadata().Generation
 	meta := rt.Metadata()
 	for _, rps := range rt.RouteStatus().Parents {
 		// Confirm the Parent is the standard Gateway kind.
@@ -316,8 +316,8 @@ func (c *gatewayRouteResolver) resolve(rt gatewayRoute) (map[string]endpoint.Tar
 			log.Debugf("Gateway %s/%s does not match %s %s/%s", namespace, ref.Name, c.src.gwName, meta.Namespace, meta.Name)
 			continue
 		}
-		// Confirm the Gateway has accepted the Route.
-		if !gwRouteIsAccepted(rps.Conditions) {
+		// Confirm the Gateway has accepted the Route, and that the generation matches.
+		if !gwRouteIsAccepted(rps.Conditions, currentGeneration) {
 			log.Debugf("Gateway %s/%s has not accepted %s %s/%s", namespace, ref.Name, c.src.rtKind, meta.Namespace, meta.Name)
 			continue
 		}
@@ -458,9 +458,9 @@ func (c *gatewayRouteResolver) routeIsAllowed(gw *v1beta1.Gateway, lis *v1.Liste
 	return false
 }
 
-func gwRouteIsAccepted(conds []metav1.Condition) bool {
+func gwRouteIsAccepted(conds []metav1.Condition, currentGeneration int64) bool {
 	for _, c := range conds {
-		if v1.RouteConditionType(c.Type) == v1.RouteConditionAccepted {
+		if v1.RouteConditionType(c.Type) == v1.RouteConditionAccepted && c.ObservedGeneration == currentGeneration {
 			return c.Status == metav1.ConditionTrue
 		}
 	}
diff --git a/source/gateway_test.go b/source/gateway_test.go
index 940622e95..92e71a91f 100644
--- a/source/gateway_test.go
+++ b/source/gateway_test.go
@@ -20,6 +20,7 @@ import (
 	"strings"
 	"testing"
 
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	v1 "sigs.k8s.io/gateway-api/apis/v1"
 )
 
@@ -245,3 +246,75 @@ func TestIsDNS1123Domain(t *testing.T) {
 		})
 	}
 }
+
+func TestGwRouteIsAccepted(t *testing.T) {
+	tests := []struct {
+		desc              string
+		conditions        []metav1.Condition
+		currentGeneration int64
+		want              bool
+	}{
+		{
+			desc: "accepted condition with matching generation",
+			conditions: []metav1.Condition{
+				{
+					Type:               string(v1.RouteConditionAccepted),
+					Status:             metav1.ConditionTrue,
+					ObservedGeneration: 1,
+				},
+			},
+			currentGeneration: 1,
+			want:              true,
+		},
+		{
+			desc: "accepted condition with different generation",
+			conditions: []metav1.Condition{
+				{
+					Type:               string(v1.RouteConditionAccepted),
+					Status:             metav1.ConditionTrue,
+					ObservedGeneration: 1,
+				},
+			},
+			currentGeneration: 2,
+			want:              false,
+		},
+		{
+			desc: "accepted condition with false status",
+			conditions: []metav1.Condition{
+				{
+					Type:               string(v1.RouteConditionAccepted),
+					Status:             metav1.ConditionFalse,
+					ObservedGeneration: 1,
+				},
+			},
+			currentGeneration: 1,
+			want:              false,
+		},
+		{
+			desc: "no accepted condition",
+			conditions: []metav1.Condition{
+				{
+					Type:               "OtherCondition",
+					Status:             metav1.ConditionTrue,
+					ObservedGeneration: 1,
+				},
+			},
+			currentGeneration: 1,
+			want:              false,
+		},
+		{
+			desc:              "empty conditions",
+			conditions:        []metav1.Condition{},
+			currentGeneration: 1,
+			want:              false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.desc, func(t *testing.T) {
+			if got := gwRouteIsAccepted(tt.conditions, tt.currentGeneration); got != tt.want {
+				t.Errorf("gwRouteIsAccepted() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}