[release/v1.6] cherry-pick: restore last transition time in merge status conditions (#8962)

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"
 )
 
@@ -31,15 +32,16 @@ func MergeConditions(conditions []metav1.Condition, updates ...metav1.Condition)
 	var additions []metav1.Condition
 	for i := range updates {
 		updates[i].Message = truncateConditionMessage(updates[i].Message)
+		update := updates[i]
 		add := true
 		for j := range conditions {
 			if conditions[j].Type == updates[i].Type {
 				add = false
-				if !reflect.DeepEqual(conditions[j], updates[i]) {
-					conditions[j].Status = updates[i].Status
-					conditions[j].Reason = updates[i].Reason
-					conditions[j].Message = updates[i].Message
-					conditions[j].ObservedGeneration = updates[i].ObservedGeneration
+				if conditionChanged(&conditions[j], &update) {
+					conditions[j].Status = update.Status
+					conditions[j].Reason = update.Reason
+					conditions[j].Message = update.Message
+					conditions[j].ObservedGeneration = update.ObservedGeneration
 					break
 				}
 			}
@@ -52,6 +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

@@ -45,6 +45,7 @@ bug fixes: |
   Fixed a control plane panic caused by concurrent Status mutation racing with the watchable Map coalesce goroutine.
   Fixed BackendTrafficPolicy rate limit `requests` values above uint32 max (4294967295) being silently truncated modulo 2^32 by the rate limit service and Envoy token bucket. The field now rejects such values at admission time with a clear schema validation error. See envoyproxy/ai-gateway#2012.
   Fixed status conditions not being updated when a route is rejected due to multiple errors.
+  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: |