From c74dfdfda66de5bc949f5f6816328df74c6a0d65 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Patryk=20Ma=C5=82ek?= <patryk.malek@konghq.com>
Date: Tue, 4 Apr 2023 13:34:11 +0200
Subject: [PATCH] fix: fix paging in GetAdminAPIsForService

---
 internal/adminapi/endpoints.go              |   1 +
 internal/adminapi/endpoints_envtest_test.go | 115 ++++++++++++++++++++
 2 files changed, 116 insertions(+)
 create mode 100644 internal/adminapi/endpoints_envtest_test.go

diff --git a/internal/adminapi/endpoints.go b/internal/adminapi/endpoints.go
index d8f89c35ae..c3944310a1 100644
--- a/internal/adminapi/endpoints.go
+++ b/internal/adminapi/endpoints.go
@@ -60,6 +60,7 @@ func GetAdminAPIsForService(
 		if endpointsList.Continue == "" {
 			break
 		}
+		continueToken = endpointsList.Continue
 	}
 	return addresses, nil
 }
diff --git a/internal/adminapi/endpoints_envtest_test.go b/internal/adminapi/endpoints_envtest_test.go
new file mode 100644
index 0000000000..1e902f2d90
--- /dev/null
+++ b/internal/adminapi/endpoints_envtest_test.go
@@ -0,0 +1,115 @@
+//go:build envtest
+// +build envtest
+
+package adminapi_test
+
+import (
+	"context"
+	"fmt"
+	"testing"
+
+	"github.com/google/uuid"
+	"github.com/samber/lo"
+	"github.com/stretchr/testify/require"
+	corev1 "k8s.io/api/core/v1"
+	discoveryv1 "k8s.io/api/discovery/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/types"
+	"k8s.io/apimachinery/pkg/util/sets"
+	"k8s.io/client-go/kubernetes/scheme"
+	ctrlclient "sigs.k8s.io/controller-runtime/pkg/client"
+
+	"github.com/kong/kubernetes-ingress-controller/v2/internal/adminapi"
+	"github.com/kong/kubernetes-ingress-controller/v2/test/envtest"
+)
+
+func TestGetAdminAPIsForServiceReturnsAllAddressesCorrectlyPagingThroughResults(t *testing.T) {
+	t.Parallel()
+
+	var client ctrlclient.Client
+	{
+		cfg := envtest.Setup(t, scheme.Scheme)
+		var err error
+		client, err = ctrlclient.New(cfg, ctrlclient.Options{
+			Scheme: scheme.Scheme,
+		})
+		require.NoError(t, err)
+	}
+
+	// In tests below we use a deferred cancel to stop the manager and not wait
+	// for its timeout.
+
+	testcases := []struct {
+		subnetC int
+		subnetD int
+	}{
+		{subnetC: 1, subnetD: 100},
+		{subnetC: 1, subnetD: 101},
+		{subnetC: 1, subnetD: 250},
+		{subnetC: 2, subnetD: 250},
+		{subnetC: 5, subnetD: 250},
+	}
+
+	for _, tc := range testcases {
+		tc := tc
+		t.Run(fmt.Sprintf("%dx%d", tc.subnetC, tc.subnetD), func(t *testing.T) {
+			t.Parallel()
+
+			ctx, cancel := context.WithCancel(context.Background())
+			defer cancel()
+
+			var (
+				ns          = envtest.CreateNamespace(ctx, t, client)
+				serviceName = uuid.NewString()
+				service     = types.NamespacedName{
+					Namespace: ns.Name,
+					Name:      serviceName,
+				}
+			)
+
+			for i := 0; i < tc.subnetC; i++ {
+				for j := 0; j < tc.subnetD; j++ {
+					es := discoveryv1.EndpointSlice{
+						ObjectMeta: metav1.ObjectMeta{
+							Name:      uuid.NewString(),
+							Namespace: ns.Name,
+							Labels: map[string]string{
+								"kubernetes.io/service-name": serviceName,
+							},
+						},
+						AddressType: discoveryv1.AddressTypeIPv4,
+						Endpoints: []discoveryv1.Endpoint{
+							{
+								Addresses: []string{fmt.Sprintf("10.0.%d.%d", i, j)},
+								Conditions: discoveryv1.EndpointConditions{
+									Ready:       lo.ToPtr(true),
+									Terminating: lo.ToPtr(false),
+								},
+								TargetRef: testPodReference("pod-1", ns.Name),
+							},
+						},
+						Ports: []discoveryv1.EndpointPort{
+							{
+								Name: lo.ToPtr("admin"),
+								Port: lo.ToPtr(int32(8444)),
+							},
+						},
+					}
+					require.NoError(t, client.Create(ctx, &es))
+				}
+			}
+
+			got, err := adminapi.GetAdminAPIsForService(context.Background(), client, service, sets.New("admin"))
+			require.NoError(t, err)
+			require.Len(t, got, tc.subnetD*tc.subnetC, "GetAdminAPIsForService should return all valid addresses")
+		})
+	}
+}
+
+func testPodReference(name, ns string) *corev1.ObjectReference {
+	return &corev1.ObjectReference{
+		Kind:      "Pod",
+		Namespace: ns,
+		Name:      name,
+	}
+}