Introduce plugins.TypedName to be used for Plugin base implementation (kubernetes-sigs#1086)

* introduce TypedName to reduce boilerplate, modify plugins

Signed-off-by: Etai Lev Ran <elevran@gmail.com>

* implement GetTypedName()

Signed-off-by: Etai Lev Ran <elevran@gmail.com>

* Remove Type() and Name() from Plugin interface

Signed-off-by: Etai Lev Ran <elevran@gmail.com>

* use TypedName as private field, not embedded

Signed-off-by: Etai Lev Ran <elevran@gmail.com>

---------

Signed-off-by: Etai Lev Ran <elevran@gmail.com>

Author: elevran

conformance/testing-epp/plugins/filter/request_header_based_filter.go

@@ -20,6 +20,7 @@ import (
 	"context"
 	"strings"
 
+	"sigs.k8s.io/gateway-api-inference-extension/pkg/epp/plugins"
 	"sigs.k8s.io/gateway-api-inference-extension/pkg/epp/scheduling/framework"
 	"sigs.k8s.io/gateway-api-inference-extension/pkg/epp/scheduling/types"
 )
@@ -38,20 +39,19 @@ var _ framework.Filter = &HeaderBasedTestingFilter{}
 // NewHeaderBasedTestingFilter initializes a new HeaderBasedTestingFilter.
 // This should only be used for testing purposes.
 func NewHeaderBasedTestingFilter() *HeaderBasedTestingFilter {
-	return &HeaderBasedTestingFilter{}
+	return &HeaderBasedTestingFilter{
+		tn: plugins.TypedName{Type: "header-based-testing", Name: "header-based-testing-filter"},
+	}
 }
 
 // HeaderBasedTestingFilter filters Pods based on an address specified in the "test-epp-endpoint-selection" request header.
-type HeaderBasedTestingFilter struct{}
-
-// Type returns the type of the filter.
-func (f *HeaderBasedTestingFilter) Type() string {
-	return "header-based-testing"
+type HeaderBasedTestingFilter struct {
+	tn plugins.TypedName
 }
 
-// Name returns the type of the filter.
-func (f *HeaderBasedTestingFilter) Name() string {
-	return "header-based-testing-filter"
+// TypedName returns the type and name tuple of this plugin instance.
+func (f *HeaderBasedTestingFilter) TypedName() plugins.TypedName {
+	return f.tn
 }
 
 // Filter selects pods that match the IP addresses specified in the request header.

pkg/epp/common/config/loader/configloader_test.go

@@ -555,15 +555,18 @@ schedulingProfiles:
 var _ framework.Filter = &test1{}
 
 type test1 struct {
+	tn        plugins.TypedName
 	Threshold int `json:"threshold"`
 }
 
-func (f *test1) Type() string {
-	return test1Type
+func newTest1() *test1 {
+	return &test1{
+		tn: plugins.TypedName{Type: test1Type, Name: "test-1"},
+	}
 }
 
-func (f *test1) Name() string {
-	return "test-1"
+func (f *test1) TypedName() plugins.TypedName {
+	return f.tn
 }
 
 // Filter filters out pods that doesn't meet the filter criteria.
@@ -575,14 +578,18 @@ func (f *test1) Filter(_ context.Context, _ *types.CycleState, _ *types.LLMReque
 var _ framework.Scorer = &test2{}
 var _ framework.PostCycle = &test2{}
 
-type test2 struct{}
+type test2 struct {
+	tn plugins.TypedName
+}
 
-func (f *test2) Type() string {
-	return test2Type
+func newTest2() *test2 {
+	return &test2{
+		tn: plugins.TypedName{Type: test2Type, Name: "test-2"},
+	}
 }
 
-func (f *test2) Name() string {
-	return "test-2"
+func (m *test2) TypedName() plugins.TypedName {
+	return m.tn
 }
 
 func (m *test2) Score(_ context.Context, _ *types.CycleState, _ *types.LLMRequest, _ []types.Pod) map[types.Pod]float64 {
@@ -594,14 +601,18 @@ func (m *test2) PostCycle(_ context.Context, _ *types.CycleState, _ *types.Profi
 // compile-time type validation
 var _ framework.Picker = &testPicker{}
 
-type testPicker struct{}
+type testPicker struct {
+	tn plugins.TypedName
+}
 
-func (p *testPicker) Type() string {
-	return testPickerType
+func newTestPicker() *testPicker {
+	return &testPicker{
+		tn: plugins.TypedName{Type: testPickerType, Name: "test-picker"},
+	}
 }
 
-func (p *testPicker) Name() string {
-	return "test-picker"
+func (p *testPicker) TypedName() plugins.TypedName {
+	return p.tn
 }
 
 func (p *testPicker) Pick(_ context.Context, _ *types.CycleState, _ []*types.ScoredPod) *types.ProfileRunResult {
@@ -611,14 +622,18 @@ func (p *testPicker) Pick(_ context.Context, _ *types.CycleState, _ []*types.Sco
 // compile-time type validation
 var _ framework.ProfileHandler = &testProfileHandler{}
 
-type testProfileHandler struct{}
+type testProfileHandler struct {
+	tn plugins.TypedName
+}
 
-func (p *testProfileHandler) Type() string {
-	return testProfileHandlerType
+func newTestProfileHandler() *testProfileHandler {
+	return &testProfileHandler{
+		tn: plugins.TypedName{Type: testProfileHandlerType, Name: "test-profile-handler"},
+	}
 }
 
-func (p *testProfileHandler) Name() string {
-	return "test-profile-handler"
+func (p *testProfileHandler) TypedName() plugins.TypedName {
+	return p.tn
 }
 
 func (p *testProfileHandler) Pick(_ context.Context, _ *types.CycleState, _ *types.LLMRequest, _ map[string]*framework.SchedulerProfile, _ map[string]*types.ProfileRunResult) map[string]*framework.SchedulerProfile {
@@ -631,28 +646,28 @@ func (p *testProfileHandler) ProcessResults(_ context.Context, _ *types.CycleSta
 
 func registerTestPlugins() {
 	plugins.Register(test1Type,
-		func(name string, parameters json.RawMessage, handle plugins.Handle) (plugins.Plugin, error) {
-			result := test1{}
-			err := json.Unmarshal(parameters, &result)
-			return &result, err
+		func(_ string, parameters json.RawMessage, _ plugins.Handle) (plugins.Plugin, error) {
+			result := newTest1()
+			err := json.Unmarshal(parameters, result)
+			return result, err
 		},
 	)
 
 	plugins.Register(test2Type,
-		func(name string, parameters json.RawMessage, handle plugins.Handle) (plugins.Plugin, error) {
-			return &test2{}, nil
+		func(_ string, _ json.RawMessage, _ plugins.Handle) (plugins.Plugin, error) {
+			return newTest2(), nil
 		},
 	)
 
 	plugins.Register(testPickerType,
-		func(name string, parameters json.RawMessage, handle plugins.Handle) (plugins.Plugin, error) {
-			return &testPicker{}, nil
+		func(_ string, _ json.RawMessage, _ plugins.Handle) (plugins.Plugin, error) {
+			return newTestPicker(), nil
 		},
 	)
 
 	plugins.Register(testProfileHandlerType,
-		func(name string, parameters json.RawMessage, handle plugins.Handle) (plugins.Plugin, error) {
-			return &testProfileHandler{}, nil
+		func(_ string, _ json.RawMessage, _ plugins.Handle) (plugins.Plugin, error) {
+			return newTestProfileHandler(), nil
 		},
 	)
 }

pkg/epp/plugins/plugins.go

@@ -24,10 +24,8 @@ import (
 // Plugin defines the interface for a plugin.
 // This interface should be embedded in all plugins across the code.
 type Plugin interface {
-	// Type returns the type of the plugin.
-	Type() string
-	// Name returns the name of this plugin instance.
-	Name() string
+	// TypedName returns the type and name tuple of this plugin instance.
+	TypedName() TypedName
 }
 
 // Handle provides plugins a set of standard data and tools to work with

pkg/epp/plugins/typedname.go

@@ -0,0 +1,38 @@
+/*
+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 plugins
+
+// TypedName is a utility struct providing a type and a name
+// to plugins.
+// It implements the Plugin interface and can be embedded in
+// plugins across the code to reduce boilerplate.
+type TypedName struct {
+	// Type returns the type of the plugin.
+	Type string
+	// Name returns the name of this plugin instance.
+	Name string
+}
+
+const (
+	Separator = "/"
+)
+
+// String returns the type and name rendered as
+// "<type>/<name>".
+func (tn *TypedName) String() string {
+	return tn.Type + Separator + tn.Name
+}

pkg/epp/requestcontrol/director.go

@@ -650,19 +650,19 @@ func RandomWeightedDraw(logger logr.Logger, model *v1alpha2.InferenceModel, seed
 func (d *Director) runPreRequestPlugins(ctx context.Context, request *schedulingtypes.LLMRequest, schedulingResult *schedulingtypes.SchedulingResult,
 	targetPort int) {
 	for _, plugin := range d.preRequestPlugins {
-		log.FromContext(ctx).V(logutil.DEBUG).Info("Running pre-request plugin", "plugin", plugin.Type())
+		log.FromContext(ctx).V(logutil.DEBUG).Info("Running pre-request plugin", "plugin", plugin.TypedName().Type)
 		before := time.Now()
 		plugin.PreRequest(ctx, request, schedulingResult, targetPort)
-		metrics.RecordRequestControlPluginProcessingLatency(PreRequestPluginType, plugin.Type(), time.Since(before))
+		metrics.RecordRequestControlPluginProcessingLatency(PreRequestPluginType, plugin.TypedName().Type, time.Since(before))
 	}
 }
 
 func (d *Director) runPostResponsePlugins(ctx context.Context, request *schedulingtypes.LLMRequest, response *Response, targetPod *backend.Pod) {
 	for _, plugin := range d.postResponsePlugins {
-		log.FromContext(ctx).V(logutil.DEBUG).Info("Running post-response plugin", "plugin", plugin.Type())
+		log.FromContext(ctx).V(logutil.DEBUG).Info("Running post-response plugin", "plugin", plugin.TypedName().Type)
 		before := time.Now()
 		plugin.PostResponse(ctx, request, response, targetPod)
-		metrics.RecordRequestControlPluginProcessingLatency(PostResponsePluginType, plugin.Type(), time.Since(before))
+		metrics.RecordRequestControlPluginProcessingLatency(PostResponsePluginType, plugin.TypedName().Type, time.Since(before))
 	}
 }
 

pkg/epp/requestcontrol/director_test.go

@@ -40,6 +40,7 @@ import (
 	"sigs.k8s.io/gateway-api-inference-extension/pkg/epp/datastore"
 	"sigs.k8s.io/gateway-api-inference-extension/pkg/epp/handlers"
 	latencypredictor "sigs.k8s.io/gateway-api-inference-extension/pkg/epp/latencypredictorasync"
+	"sigs.k8s.io/gateway-api-inference-extension/pkg/epp/plugins"
 	schedulingtypes "sigs.k8s.io/gateway-api-inference-extension/pkg/epp/scheduling/types"
 	errutil "sigs.k8s.io/gateway-api-inference-extension/pkg/epp/util/error"
 	logutil "sigs.k8s.io/gateway-api-inference-extension/pkg/epp/util/logging"
@@ -894,9 +895,7 @@ func pointer(v int32) *int32 {
 }
 
 func TestDirector_HandleResponse(t *testing.T) {
-	pr1 := &testPostResponse{
-		TypeRes: "pr1",
-	}
+	pr1 := newTestPostResponse("pr1")
 
 	ctx := logutil.NewTestLoggerIntoContext(context.Background())
 	ds := datastore.NewDatastore(t.Context(), nil)
@@ -932,14 +931,25 @@ func TestDirector_HandleResponse(t *testing.T) {
 	}
 }
 
+const (
+	testPostResponseType = "test-post-response"
+)
+
 type testPostResponse struct {
-	TypeRes                 string
+	tn                      plugins.TypedName
 	lastRespOnResponse      *Response
 	lastTargetPodOnResponse string
 }
 
-func (p *testPostResponse) Type() string { return p.TypeRes }
-func (p *testPostResponse) Name() string { return "test-post-response" }
+func newTestPostResponse(name string) *testPostResponse {
+	return &testPostResponse{
+		tn: plugins.TypedName{Type: testPostResponseType, Name: name},
+	}
+}
+
+func (p *testPostResponse) TypedName() plugins.TypedName {
+	return p.tn
+}
 
 func (p *testPostResponse) PostResponse(_ context.Context, _ *schedulingtypes.LLMRequest, response *Response, targetPod *backend.Pod) {
 	p.lastRespOnResponse = response

pkg/epp/scheduling/framework/plugins/filter/decision_tree_filter.go

@@ -36,9 +36,11 @@ const (
 // compile-time type assertion
 var _ framework.Filter = &DecisionTreeFilter{}
 
-// DecisionTreeFilter applies current fitler, and then recursively applies next filters
+// DecisionTreeFilter applies current filter, and then recursively applies next filters
 // depending success or failure of the current filter.
 // It can be used to construct a flow chart algorithm.
+// Since a DecisionTreeFilter takes on the type and name of the current filter,
+// it is not embedding a fixed plugins.TypeName.
 type DecisionTreeFilter struct {
 	Current framework.Filter
 	// NextOnSuccess filter will be applied after successfully applying the current filter.
@@ -131,20 +133,14 @@ func loadDecisionTreeEntry(entry *decisionTreeFilterEntry, handle plugins.Handle
 	return nil, errors.New("either pluginRef or decisionTree must be specified")
 }
 
-// Type returns the type of the filter.
-func (f *DecisionTreeFilter) Type() string {
+func (f *DecisionTreeFilter) TypedName() plugins.TypedName {
 	if f == nil {
-		return "nil"
+		// TODO: this keeps the previous behavior ("nil"/"") - not sure
+		// why done this way.
+		// Change to empty TypedName or some more meaningful values?
+		return plugins.TypedName{Type: "nil", Name: ""}
 	}
-	return f.Current.Type()
-}
-
-// Name returns the name of the filter.
-func (f *DecisionTreeFilter) Name() string {
-	if f == nil {
-		return ""
-	}
-	return f.Current.Name()
+	return f.Current.TypedName()
 }
 
 // Filter filters out pods that doesn't meet the filter criteria.
@@ -161,7 +157,7 @@ func (f *DecisionTreeFilter) Filter(ctx context.Context, cycleState *types.Cycle
 		if f.NextOnSuccess != nil {
 			next = f.NextOnSuccess
 		}
-		loggerTrace.Info("Filter succeeded", "filter", f.Type(), "next", next.Type(), "filteredPodCount", len(filteredPod))
+		loggerTrace.Info("Filter succeeded", "filter", f.TypedName(), "next", next.TypedName(), "filteredPodCount", len(filteredPod))
 		// On success, pass the filtered result to the next filter.
 		return next.Filter(ctx, cycleState, request, filteredPod)
 	} else {
@@ -172,7 +168,7 @@ func (f *DecisionTreeFilter) Filter(ctx context.Context, cycleState *types.Cycle
 		if f.NextOnFailure != nil {
 			next = f.NextOnFailure
 		}
-		loggerTrace.Info("Filter failed", "filter", f.Type(), "next", next.Type())
+		loggerTrace.Info("Filter failed", "filter", f.TypedName(), "next", next.TypedName())
 		// On failure, pass the initial set of pods to the next filter.
 		return next.Filter(ctx, cycleState, request, pods)
 	}