Revert "Replace EndpointSlice reconciler with pod list backed by informer (kubernetes-sigs#271)"

This reverts commit 9298849.

Author: kfswain

.golangci.yml

@@ -14,6 +14,7 @@ linters:
     - dupword
     - durationcheck
     - fatcontext
+    - gci
     - ginkgolinter
     - gocritic
     - govet

pkg/ext-proc/backend/datastore.go

@@ -1,36 +1,22 @@
 package backend
 
 import (
-	"context"
 	"errors"
 	"math/rand"
 	"sync"
-	"time"
 
-	"github.com/google/go-cmp/cmp"
 	"inference.networking.x-k8s.io/gateway-api-inference-extension/api/v1alpha1"
 	logutil "inference.networking.x-k8s.io/gateway-api-inference-extension/pkg/ext-proc/util/logging"
 	corev1 "k8s.io/api/core/v1"
-	v1 "k8s.io/api/core/v1"
-	"k8s.io/apimachinery/pkg/api/meta"
-	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
-	"k8s.io/apimachinery/pkg/labels"
-	"k8s.io/client-go/informers"
-	informersv1 "k8s.io/client-go/informers/core/v1"
-	"k8s.io/client-go/kubernetes"
-	clientset "k8s.io/client-go/kubernetes"
-	listersv1 "k8s.io/client-go/listers/core/v1"
-	"k8s.io/client-go/tools/cache"
 	"k8s.io/klog/v2"
 )
 
 func NewK8sDataStore(options ...K8sDatastoreOption) *K8sDatastore {
 	store := &K8sDatastore{
 		poolMu:          sync.RWMutex{},
 		InferenceModels: &sync.Map{},
+		pods:            &sync.Map{},
 	}
-
-	store.podListerFactory = store.createPodLister
 	for _, opt := range options {
 		opt(store)
 	}
@@ -39,68 +25,29 @@ func NewK8sDataStore(options ...K8sDatastoreOption) *K8sDatastore {
 
 // The datastore is a local cache of relevant data for the given InferencePool (currently all pulled from k8s-api)
 type K8sDatastore struct {
-	client kubernetes.Interface
 	// poolMu is used to synchronize access to the inferencePool.
-	poolMu           sync.RWMutex
-	inferencePool    *v1alpha1.InferencePool
-	podListerFactory PodListerFactory
-	podLister        *PodLister
-	InferenceModels  *sync.Map
+	poolMu          sync.RWMutex
+	inferencePool   *v1alpha1.InferencePool
+	InferenceModels *sync.Map
+	pods            *sync.Map
 }
 
 type K8sDatastoreOption func(*K8sDatastore)
-type PodListerFactory func(*v1alpha1.InferencePool) *PodLister
 
 // WithPods can be used in tests to override the pods.
-func WithPodListerFactory(factory PodListerFactory) K8sDatastoreOption {
+func WithPods(pods []*PodMetrics) K8sDatastoreOption {
 	return func(store *K8sDatastore) {
-		store.podListerFactory = factory
+		store.pods = &sync.Map{}
+		for _, pod := range pods {
+			store.pods.Store(pod.Pod, true)
+		}
 	}
 }
 
-type PodLister struct {
-	Lister         listersv1.PodLister
-	sharedInformer informers.SharedInformerFactory
-}
-
-func (l *PodLister) listEverything() ([]*corev1.Pod, error) {
-	return l.Lister.List(labels.Everything())
-
-}
-
-func (ds *K8sDatastore) SetClient(client kubernetes.Interface) {
-	ds.client = client
-}
-
 func (ds *K8sDatastore) setInferencePool(pool *v1alpha1.InferencePool) {
 	ds.poolMu.Lock()
 	defer ds.poolMu.Unlock()
-
-	if ds.inferencePool != nil && cmp.Equal(ds.inferencePool.Spec.Selector, pool.Spec.Selector) {
-		// Pool updated, but the selector stayed the same, so no need to change the informer.
-		ds.inferencePool = pool
-		return
-	}
-
-	// New pool or selector updated.
 	ds.inferencePool = pool
-
-	if ds.podLister != nil && ds.podLister.sharedInformer != nil {
-		// Shutdown the old informer async since this takes a few seconds.
-		go func() {
-			ds.podLister.sharedInformer.Shutdown()
-		}()
-	}
-
-	if ds.podListerFactory != nil {
-		// Create a new informer with the new selector.
-		ds.podLister = ds.podListerFactory(ds.inferencePool)
-		if ds.podLister != nil && ds.podLister.sharedInformer != nil {
-			ctx := context.Background()
-			ds.podLister.sharedInformer.Start(ctx.Done())
-			ds.podLister.sharedInformer.WaitForCacheSync(ctx.Done())
-		}
-	}
 }
 
 func (ds *K8sDatastore) getInferencePool() (*v1alpha1.InferencePool, error) {
@@ -112,58 +59,13 @@ func (ds *K8sDatastore) getInferencePool() (*v1alpha1.InferencePool, error) {
 	return ds.inferencePool, nil
 }
 
-func (ds *K8sDatastore) createPodLister(pool *v1alpha1.InferencePool) *PodLister {
-	if ds.client == nil {
-		return nil
-	}
-	klog.V(logutil.DEFAULT).Infof("Creating informer for pool %v", pool.Name)
-	selectorSet := make(map[string]string)
-	for k, v := range pool.Spec.Selector {
-		selectorSet[string(k)] = string(v)
-	}
-
-	newPodInformer := func(cs clientset.Interface, resyncPeriod time.Duration) cache.SharedIndexInformer {
-		informer := informersv1.NewFilteredPodInformer(cs, pool.Namespace, resyncPeriod, cache.Indexers{}, func(options *metav1.ListOptions) {
-			options.LabelSelector = labels.SelectorFromSet(selectorSet).String()
-		})
-		err := informer.SetTransform(func(obj interface{}) (interface{}, error) {
-			// Remove unnecessary fields to improve memory footprint.
-			if accessor, err := meta.Accessor(obj); err == nil {
-				if accessor.GetManagedFields() != nil {
-					accessor.SetManagedFields(nil)
-				}
-			}
-			return obj, nil
-		})
-		if err != nil {
-			klog.Errorf("Failed to set pod transformer: %v", err)
-		}
-		return informer
-	}
-	// 0 means we disable resyncing, it is not really useful to resync every hour (the controller-runtime default),
-	// if things go wrong in the watch, no one will wait for an hour for things to get fixed.
-	// As precedence, kube-scheduler also disables this since it is expensive to list all pods from the api-server regularly.
-	resyncPeriod := time.Duration(0)
-	sharedInformer := informers.NewSharedInformerFactory(ds.client, resyncPeriod)
-	sharedInformer.InformerFor(&v1.Pod{}, newPodInformer)
-
-	return &PodLister{
-		Lister:         sharedInformer.Core().V1().Pods().Lister(),
-		sharedInformer: sharedInformer,
-	}
-}
-
-func (ds *K8sDatastore) getPods() ([]*corev1.Pod, error) {
-	ds.poolMu.RLock()
-	defer ds.poolMu.RUnlock()
-	if !ds.HasSynced() {
-		return nil, errors.New("InferencePool is not initialized in datastore")
-	}
-	pods, err := ds.podLister.listEverything()
-	if err != nil {
-		return nil, err
-	}
-	return pods, nil
+func (ds *K8sDatastore) GetPodIPs() []string {
+	var ips []string
+	ds.pods.Range(func(name, pod any) bool {
+		ips = append(ips, pod.(*corev1.Pod).Status.PodIP)
+		return true
+	})
+	return ips
 }
 
 func (s *K8sDatastore) FetchModelData(modelName string) (returnModel *v1alpha1.InferenceModel) {

pkg/ext-proc/backend/endpointslice_reconciler.go

@@ -0,0 +1,109 @@
+package backend
+
+import (
+	"context"
+	"strconv"
+	"time"
+
+	"inference.networking.x-k8s.io/gateway-api-inference-extension/api/v1alpha1"
+	logutil "inference.networking.x-k8s.io/gateway-api-inference-extension/pkg/ext-proc/util/logging"
+	discoveryv1 "k8s.io/api/discovery/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/client-go/tools/record"
+	klog "k8s.io/klog/v2"
+	ctrl "sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/builder"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+	"sigs.k8s.io/controller-runtime/pkg/predicate"
+)
+
+var (
+	serviceOwnerLabel = "kubernetes.io/service-name"
+)
+
+type EndpointSliceReconciler struct {
+	client.Client
+	Scheme      *runtime.Scheme
+	Record      record.EventRecorder
+	ServiceName string
+	Zone        string
+	Datastore   *K8sDatastore
+}
+
+func (c *EndpointSliceReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ctrl.Result, error) {
+	inferencePool, err := c.Datastore.getInferencePool()
+	if err != nil {
+		klog.V(logutil.DEFAULT).Infof("Skipping reconciling EndpointSlice because the InferencePool is not available yet: %v", err)
+		return ctrl.Result{Requeue: true, RequeueAfter: time.Second}, nil
+	}
+
+	klog.V(logutil.DEFAULT).Info("Reconciling EndpointSlice ", req.NamespacedName)
+
+	endpointSlice := &discoveryv1.EndpointSlice{}
+	if err := c.Get(ctx, req.NamespacedName, endpointSlice); err != nil {
+		klog.Errorf("Unable to get EndpointSlice: %v", err)
+		return ctrl.Result{}, err
+	}
+	c.updateDatastore(endpointSlice, inferencePool)
+
+	return ctrl.Result{}, nil
+}
+
+// TODO: Support multiple endpointslices for a single service
+func (c *EndpointSliceReconciler) updateDatastore(
+	slice *discoveryv1.EndpointSlice,
+	inferencePool *v1alpha1.InferencePool) {
+	podMap := make(map[Pod]bool)
+
+	for _, endpoint := range slice.Endpoints {
+		klog.V(logutil.DEFAULT).Infof("Zone: %v \n endpoint: %+v \n", c.Zone, endpoint)
+		if c.validPod(endpoint) {
+			pod := Pod{
+				Name:    endpoint.TargetRef.Name,
+				Address: endpoint.Addresses[0] + ":" + strconv.Itoa(int(inferencePool.Spec.TargetPortNumber)),
+			}
+			podMap[pod] = true
+			klog.V(logutil.DEFAULT).Infof("Storing pod %v", pod)
+			c.Datastore.pods.Store(pod, true)
+		}
+	}
+
+	removeOldPods := func(k, v any) bool {
+		pod, ok := k.(Pod)
+		if !ok {
+			klog.Errorf("Unable to cast key to Pod: %v", k)
+			return false
+		}
+		if _, ok := podMap[pod]; !ok {
+			klog.V(logutil.DEFAULT).Infof("Removing pod %v", pod)
+			c.Datastore.pods.Delete(pod)
+		}
+		return true
+	}
+	c.Datastore.pods.Range(removeOldPods)
+}
+
+func (c *EndpointSliceReconciler) SetupWithManager(mgr ctrl.Manager) error {
+	ownsEndPointSlice := func(object client.Object) bool {
+		// Check if the object is an EndpointSlice
+		endpointSlice, ok := object.(*discoveryv1.EndpointSlice)
+		if !ok {
+			return false
+		}
+
+		gotLabel := endpointSlice.ObjectMeta.Labels[serviceOwnerLabel]
+		wantLabel := c.ServiceName
+		return gotLabel == wantLabel
+	}
+
+	return ctrl.NewControllerManagedBy(mgr).
+		For(&discoveryv1.EndpointSlice{},
+			builder.WithPredicates(predicate.NewPredicateFuncs(ownsEndPointSlice))).
+		Complete(c)
+}
+
+func (c *EndpointSliceReconciler) validPod(endpoint discoveryv1.Endpoint) bool {
+	validZone := c.Zone == "" || c.Zone != "" && *endpoint.Zone == c.Zone
+	return validZone && *endpoint.Conditions.Ready
+
+}