fix: restore last transition time in merge status conditions

internal/gatewayapi/status/conditions.go

@@ -14,9 +14,10 @@
 package status
 
 import (
-	"reflect"
 	"unicode"
 
+	"github.com/google/go-cmp/cmp"
+	"github.com/google/go-cmp/cmp/cmpopts"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
 
@@ -36,7 +37,7 @@ func MergeConditions(conditions []metav1.Condition, updates ...metav1.Condition)
 		for j := range conditions {
 			if conditions[j].Type == update.Type {
 				add = false
-				if !reflect.DeepEqual(conditions[j], update) {
+				if conditionChanged(&conditions[j], &update) {
 					conditions[j].Status = update.Status
 					conditions[j].Reason = update.Reason
 					conditions[j].Message = update.Message
@@ -53,6 +54,11 @@ func MergeConditions(conditions []metav1.Condition, updates ...metav1.Condition)
 	return conditions
 }
 
+func conditionChanged(a, b *metav1.Condition) bool {
+	opts := cmpopts.IgnoreFields(metav1.Condition{}, "Type", "LastTransitionTime")
+	return !cmp.Equal(*a, *b, opts)
+}
+
 func newCondition(t string, status metav1.ConditionStatus, reason, msg string, og int64) metav1.Condition {
 	return metav1.Condition{
 		Type:               t,

internal/gatewayapi/status/conditions_test.go

@@ -15,7 +15,6 @@ package status
 
 import (
 	"errors"
-	"reflect"
 	"strings"
 	"testing"
 
@@ -41,6 +40,20 @@ func TestConditionChanged(t *testing.T) {
 			a:        metav1.Condition{},
 			b:        metav1.Condition{},
 		},
+		{
+			name:     "condition LastTransitionTime should be ignored",
+			expected: false,
+			a: metav1.Condition{
+				Type:               string(gwapiv1.GatewayClassConditionStatusAccepted),
+				Status:             metav1.ConditionTrue,
+				LastTransitionTime: metav1.Unix(0, 0),
+			},
+			b: metav1.Condition{
+				Type:               string(gwapiv1.GatewayClassConditionStatusAccepted),
+				Status:             metav1.ConditionTrue,
+				LastTransitionTime: metav1.Unix(1, 0),
+			},
+		},
 		{
 			name:     "check condition reason differs",
 			expected: true,
@@ -70,7 +83,7 @@ func TestConditionChanged(t *testing.T) {
 	}
 
 	for _, tc := range testCases {
-		if got := !reflect.DeepEqual(tc.a, tc.b); got != tc.expected {
+		if got := conditionChanged(&tc.a, &tc.b); got != tc.expected {
 			assert.Equal(t, tc.expected, got, tc.name)
 		}
 	}

release-notes/current.yaml

@@ -15,6 +15,7 @@ bug fixes: |
   Fixed ListenerSet and its listeners incorrectly setting `Accepted: False` for InvalidCertificateRef and RefNotPermitted, inconsistent with Gateway behavior and the Gateway API spec.
   Fixed active HTTP health checks to use Backend endpoint hostnames before falling back to the effective Route hostname.
   Fixed HTTPS listeners with overlapping hostnames but disjoint certificate SANs to preserve HTTP/2 ALPN by default.
+  Fixed Gateway getting stuck at `Programmed=False` after its LoadBalancer Service IP was restored, by ignoring `LastTransitionTime` when comparing status conditions.
 
 # Enhancements that improve performance.
 performance improvements: |