extract pod representation from backend/metrics to backend

pkg/epp/backend/metrics/fake.go

@@ -24,20 +24,21 @@ import (
 	corev1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/types"
 	"sigs.k8s.io/controller-runtime/pkg/log"
+	"sigs.k8s.io/gateway-api-inference-extension/pkg/epp/backend"
 	logutil "sigs.k8s.io/gateway-api-inference-extension/pkg/epp/util/logging"
 )
 
 // FakePodMetrics is an implementation of PodMetrics that doesn't run the async refresh loop.
 type FakePodMetrics struct {
-	Pod     *Pod
+	Pod     *backend.Pod
 	Metrics *Metrics
 }
 
 func (fpm *FakePodMetrics) String() string {
 	return fmt.Sprintf("Pod: %v; Metrics: %v", fpm.GetPod(), fpm.GetMetrics())
 }
 
-func (fpm *FakePodMetrics) GetPod() *Pod {
+func (fpm *FakePodMetrics) GetPod() *backend.Pod {
 	return fpm.Pod
 }
 func (fpm *FakePodMetrics) GetMetrics() *Metrics {
@@ -55,7 +56,7 @@ type FakePodMetricsClient struct {
 	Res   map[types.NamespacedName]*Metrics
 }
 
-func (f *FakePodMetricsClient) FetchMetrics(ctx context.Context, pod *Pod, existing *Metrics, port int32) (*Metrics, error) {
+func (f *FakePodMetricsClient) FetchMetrics(ctx context.Context, pod *backend.Pod, existing *Metrics, port int32) (*Metrics, error) {
 	f.errMu.RLock()
 	err, ok := f.Err[pod.NamespacedName]
 	f.errMu.RUnlock()

pkg/epp/backend/metrics/metrics.go

@@ -26,6 +26,7 @@ import (
 	dto "github.com/prometheus/client_model/go"
 	"github.com/prometheus/common/expfmt"
 	"go.uber.org/multierr"
+	"sigs.k8s.io/gateway-api-inference-extension/pkg/epp/backend"
 )
 
 const (
@@ -39,15 +40,8 @@ type PodMetricsClientImpl struct {
 	MetricMapping *MetricMapping
 }
 
-// FetchMetrics fetches metrics from a given pod, clones the existing metrics object and returns an
-// updated one.
-func (p *PodMetricsClientImpl) FetchMetrics(
-	ctx context.Context,
-	pod *Pod,
-	existing *Metrics,
-	port int32,
-) (*Metrics, error) {
-
+// FetchMetrics fetches metrics from a given pod, clones the existing metrics object and returns an updated one.
+func (p *PodMetricsClientImpl) FetchMetrics(ctx context.Context, pod *backend.Pod, existing *Metrics, port int32) (*Metrics, error) {
 	// Currently the metrics endpoint is hard-coded, which works with vLLM.
 	// TODO(https://github.com/kubernetes-sigs/gateway-api-inference-extension/issues/16): Consume this from InferencePool config.
 	url := "http://" + pod.Address + ":" + strconv.Itoa(int(port)) + "/metrics"

pkg/epp/backend/metrics/metrics_test.go

@@ -30,6 +30,7 @@ import (
 	"google.golang.org/protobuf/proto"
 	"k8s.io/apimachinery/pkg/types"
 
+	"sigs.k8s.io/gateway-api-inference-extension/pkg/epp/backend"
 	logutil "sigs.k8s.io/gateway-api-inference-extension/pkg/epp/util/logging"
 )
 
@@ -486,7 +487,7 @@ func TestPromToPodMetrics(t *testing.T) {
 // there's no server running on the specified port.
 func TestFetchMetrics(t *testing.T) {
 	ctx := logutil.NewTestLoggerIntoContext(context.Background())
-	pod := &Pod{
+	pod := &backend.Pod{
 		Address: "127.0.0.1",
 		NamespacedName: types.NamespacedName{
 			Namespace: "test",

pkg/epp/backend/metrics/pod_metrics.go

@@ -27,6 +27,7 @@ import (
 	corev1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/types"
 
+	"sigs.k8s.io/gateway-api-inference-extension/pkg/epp/backend"
 	logutil "sigs.k8s.io/gateway-api-inference-extension/pkg/epp/util/logging"
 )
 
@@ -35,7 +36,7 @@ const (
 )
 
 type podMetrics struct {
-	pod      atomic.Pointer[Pod]
+	pod      atomic.Pointer[backend.Pod]
 	metrics  atomic.Pointer[Metrics]
 	pmc      PodMetricsClient
 	ds       Datastore
@@ -48,14 +49,14 @@ type podMetrics struct {
 }
 
 type PodMetricsClient interface {
-	FetchMetrics(ctx context.Context, pod *Pod, existing *Metrics, port int32) (*Metrics, error)
+	FetchMetrics(ctx context.Context, pod *backend.Pod, existing *Metrics, port int32) (*Metrics, error)
 }
 
 func (pm *podMetrics) String() string {
 	return fmt.Sprintf("Pod: %v; Metrics: %v", pm.GetPod(), pm.GetMetrics())
 }
 
-func (pm *podMetrics) GetPod() *Pod {
+func (pm *podMetrics) GetPod() *backend.Pod {
 	return pm.pod.Load()
 }
 
@@ -67,8 +68,8 @@ func (pm *podMetrics) UpdatePod(in *corev1.Pod) {
 	pm.pod.Store(toInternalPod(in))
 }
 
-func toInternalPod(in *corev1.Pod) *Pod {
-	return &Pod{
+func toInternalPod(in *corev1.Pod) *backend.Pod {
+	return &backend.Pod{
 		NamespacedName: types.NamespacedName{
 			Name:      in.Name,
 			Namespace: in.Namespace,

pkg/epp/backend/metrics/types.go

@@ -24,8 +24,8 @@ import (
 	"time"
 
 	corev1 "k8s.io/api/core/v1"
-	"k8s.io/apimachinery/pkg/types"
 	"sigs.k8s.io/controller-runtime/pkg/log"
+	"sigs.k8s.io/gateway-api-inference-extension/pkg/epp/backend"
 )
 
 func NewPodMetricsFactory(pmc PodMetricsClient, refreshMetricsInterval time.Duration) *PodMetricsFactory {
@@ -58,38 +58,13 @@ func (f *PodMetricsFactory) NewPodMetrics(parentCtx context.Context, in *corev1.
 }
 
 type PodMetrics interface {
-	GetPod() *Pod
+	GetPod() *backend.Pod
 	GetMetrics() *Metrics
 	UpdatePod(*corev1.Pod)
 	StopRefreshLoop()
 	String() string
 }
 
-type Pod struct {
-	NamespacedName types.NamespacedName
-	Address        string
-}
-
-func (p *Pod) String() string {
-	if p == nil {
-		return ""
-	}
-	return fmt.Sprintf("%+v", *p)
-}
-
-func (p *Pod) Clone() *Pod {
-	if p == nil {
-		return nil
-	}
-	return &Pod{
-		NamespacedName: types.NamespacedName{
-			Name:      p.NamespacedName.Name,
-			Namespace: p.NamespacedName.Namespace,
-		},
-		Address: p.Address,
-	}
-}
-
 type Metrics struct {
 	// ActiveModels is a set of models(including LoRA adapters) that are currently cached to GPU.
 	ActiveModels  map[string]int

pkg/epp/backend/pod.go

@@ -0,0 +1,45 @@
+/*
+Copyright 2025 The Kubernetes Authors.
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+    http://www.apache.org/licenses/LICENSE-2.0
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package backend
+
+import (
+	"fmt"
+
+	"k8s.io/apimachinery/pkg/types"
+)
+
+type Pod struct {
+	NamespacedName types.NamespacedName
+	Address        string
+}
+
+func (p *Pod) String() string {
+	if p == nil {
+		return ""
+	}
+	return fmt.Sprintf("%+v", *p)
+}
+
+func (p *Pod) Clone() *Pod {
+	if p == nil {
+		return nil
+	}
+	return &Pod{
+		NamespacedName: types.NamespacedName{
+			Name:      p.NamespacedName.Name,
+			Namespace: p.NamespacedName.Namespace,
+		},
+		Address: p.Address,
+	}
+}

pkg/epp/handlers/server.go

@@ -34,7 +34,7 @@ import (
 	"google.golang.org/protobuf/types/known/structpb"
 	"sigs.k8s.io/controller-runtime/pkg/log"
 	"sigs.k8s.io/gateway-api-inference-extension/api/v1alpha2"
-	backendmetrics "sigs.k8s.io/gateway-api-inference-extension/pkg/epp/backend/metrics"
+	"sigs.k8s.io/gateway-api-inference-extension/pkg/epp/backend"
 	"sigs.k8s.io/gateway-api-inference-extension/pkg/epp/datastore"
 	"sigs.k8s.io/gateway-api-inference-extension/pkg/epp/metrics"
 	schedulingtypes "sigs.k8s.io/gateway-api-inference-extension/pkg/epp/scheduling/types"
@@ -447,7 +447,7 @@ func RandomWeightedDraw(logger logr.Logger, model *v1alpha2.InferenceModel, seed
 	return ""
 }
 
-func GetRandomPod(ds datastore.Datastore) *backendmetrics.Pod {
+func GetRandomPod(ds datastore.Datastore) *backend.Pod {
 	pods := ds.PodGetAll()
 	if len(pods) == 0 {
 		return nil

pkg/epp/scheduling/plugins/filter/filter_test.go

@@ -22,6 +22,7 @@ import (
 
 	"github.com/google/go-cmp/cmp"
 	k8stypes "k8s.io/apimachinery/pkg/types"
+	"sigs.k8s.io/gateway-api-inference-extension/pkg/epp/backend"
 	backendmetrics "sigs.k8s.io/gateway-api-inference-extension/pkg/epp/backend/metrics"
 	"sigs.k8s.io/gateway-api-inference-extension/pkg/epp/scheduling/config"
 	"sigs.k8s.io/gateway-api-inference-extension/pkg/epp/scheduling/types"
@@ -227,7 +228,7 @@ func TestLoRASoftAffinityDistribution(t *testing.T) {
 	// Test setup: One affinity pod and one available pod
 	pods := []types.Pod{
 		&types.PodMetrics{
-			Pod: &backendmetrics.Pod{NamespacedName: k8stypes.NamespacedName{Name: "affinity-pod"}},
+			Pod: &backend.Pod{NamespacedName: k8stypes.NamespacedName{Name: "affinity-pod"}},
 			Metrics: &backendmetrics.Metrics{
 				MaxActiveModels: 2,
 				ActiveModels: map[string]int{
@@ -236,7 +237,7 @@ func TestLoRASoftAffinityDistribution(t *testing.T) {
 			},
 		},
 		&types.PodMetrics{
-			Pod: &backendmetrics.Pod{NamespacedName: k8stypes.NamespacedName{Name: "available-pod"}},
+			Pod: &backend.Pod{NamespacedName: k8stypes.NamespacedName{Name: "available-pod"}},
 			Metrics: &backendmetrics.Metrics{
 				MaxActiveModels: 2,
 				ActiveModels:    map[string]int{},