Read metrics Datasource configuration from config file

config/charts/epplib/templates/_config.yaml

@@ -12,6 +12,12 @@ data:
     - type: queue-scorer
     - type: kv-cache-utilization-scorer
     - type: prefix-cache-scorer
+    - type: metrics-data-source
+      parameters:
+        scheme: {{ .Values.inferenceExtension.metricsDataSource.scheme | default "http" | quote }}
+        path: {{ .Values.inferenceExtension.metricsDataSource.path | default "/metrics" | quote }}
+        insecureSkipVerify: {{ .Values.inferenceExtension.metricsDataSource.insecureSkipVerify | default true }}
+    - type: core-metrics-extractor
     {{- if .Values.inferenceExtension.latencyPredictor.enabled }}
     - type: predicted-latency-scorer
       parameters:

config/charts/inferencepool/values.yaml

@@ -81,6 +81,16 @@ inferenceExtension:
     # common latencyPredictor setting exists in config/charts/inference-extension/values.yaml
     enabled: false
 
+  # Metrics DataSource Configuration
+  # These values configure how the EPP scrapes metrics from model server pods.
+  metricsDataSource:
+    # scheme is the HTTP scheme used to scrape metrics (http or https).
+    scheme: "http"
+    # path is the URL path on the model server pod that exposes Prometheus metrics.
+    path: "/metrics"
+    # insecureSkipVerify disables TLS certificate verification when scheme is https.
+    insecureSkipVerify: true
+
 inferencePool:
   targetPorts:
     - number: 8000

config/charts/standalone/values.yaml

@@ -301,6 +301,16 @@ inferenceExtension:
     # common latencyPredictor setting exists in config/charts/inference-extension/values.yaml
     enabled: false
 
+  # Metrics DataSource Configuration
+  # These values configure how the EPP scrapes metrics from model server pods.
+  metricsDataSource:
+    # scheme is the HTTP scheme used to scrape metrics (http or https).
+    scheme: "http"
+    # path is the URL path on the model server pod that exposes Prometheus metrics.
+    path: "/metrics"
+    # insecureSkipVerify disables TLS certificate verification when scheme is https.
+    insecureSkipVerify: true
+
 # Options: ["gke"]
 provider:
   name: none

pkg/epp/backend/metrics/podmetrics_parity_test.go

@@ -18,6 +18,7 @@ package metrics
 
 import (
 	"context"
+	"encoding/json"
 	"errors"
 	"fmt"
 	"net/http"
@@ -30,7 +31,6 @@ import (
 	"github.com/google/go-cmp/cmp/cmpopts"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
-	"github.com/spf13/pflag"
 	"github.com/stretchr/testify/assert"
 
 	fwkdl "sigs.k8s.io/gateway-api-inference-extension/pkg/epp/framework/interface/datalayer"
@@ -316,15 +316,13 @@ func parseWithDatalayerMetrics(t *testing.T, ctx context.Context, urlStr string)
 		return nil, fmt.Errorf("failed to parse URL: %w", err)
 	}
 
-	cleanup := setupTestFlags(t) // set-up test flags and restore on cleanup
-	defer cleanup()
-
-	// CLI flags to match the test server URL
-	if err := pflag.CommandLine.Set("model-server-metrics-scheme", parsedURL.Scheme); err != nil {
-		return nil, fmt.Errorf("failed to set scheme flag: %w", err)
-	}
-	if err := pflag.CommandLine.Set("model-server-metrics-path", parsedURL.Path); err != nil {
-		return nil, fmt.Errorf("failed to set path flag: %w", err)
+	// Pass scheme and path directly as plugin parameters — no CLI flags needed.
+	params, err := json.Marshal(map[string]any{
+		"scheme": parsedURL.Scheme,
+		"path":   parsedURL.Path,
+	})
+	if err != nil {
+		return nil, fmt.Errorf("failed to marshal datasource parameters: %w", err)
 	}
 
 	mapping, err := metricextractor.NewMapping(
@@ -350,8 +348,8 @@ func parseWithDatalayerMetrics(t *testing.T, ctx context.Context, urlStr string)
 
 	plugin, err := sourcemetrics.MetricsDataSourceFactory(
 		"test-metrics-source",
-		nil, // use default parameters from flags
-		nil, // no plugin handle needed for test
+		params, // configure scheme and path via parameters
+		nil,    // no plugin handle needed for test
 	)
 	if err != nil {
 		return nil, fmt.Errorf("failed to create data source: %w", err)
@@ -381,22 +379,6 @@ func parseWithDatalayerMetrics(t *testing.T, ctx context.Context, urlStr string)
 	return endpoint.GetMetrics(), nil
 }
 
-// setupTestFlags creates a temporary FlagSet for testing and returns a cleanup function
-func setupTestFlags(t *testing.T) func() {
-	t.Helper()
-	originalFlags := pflag.CommandLine
-	testFlags := pflag.NewFlagSet("test", pflag.ContinueOnError)
-	pflag.CommandLine = testFlags
-
-	testFlags.String("model-server-metrics-scheme", "http", "Protocol scheme used in scraping metrics from endpoints")
-	testFlags.String("model-server-metrics-path", "/metrics", "URL path used in scraping metrics from endpoints")
-	testFlags.Bool("model-server-metrics-https-insecure-skip-verify", false, "Skip TLS verification for HTTPS metrics endpoints")
-
-	return func() {
-		pflag.CommandLine = originalFlags
-	}
-}
-
 // createMockServer creates an HTTP test server that serves Prometheus metrics
 func createMockServer(metrics []MetricMock) *httptest.Server {
 	reg := prometheus.NewRegistry()

pkg/epp/framework/plugins/datalayer/extractor/metrics/factories.go

@@ -25,7 +25,7 @@ import (
 )
 
 const (
-	MetricsExtractorType = "model-server-protocol-metrics"
+	MetricsExtractorType = "core-metrics-extractor"
 )
 
 // Configuration parameters for metrics data source and extractor.

pkg/epp/framework/plugins/datalayer/source/metrics/datasource.go

@@ -24,15 +24,23 @@ import (
 
 	"github.com/prometheus/common/expfmt"
 	"github.com/prometheus/common/model"
-	"github.com/spf13/pflag"
+	flag "github.com/spf13/pflag"
 
 	fwkplugin "sigs.k8s.io/gateway-api-inference-extension/pkg/epp/framework/interface/plugin"
 	"sigs.k8s.io/gateway-api-inference-extension/pkg/epp/framework/plugins/datalayer/source/http"
 )
 
 const MetricsDataSourceType = "metrics-data-source"
 
-// Data source configuration parameters
+// Default values for the metrics data source configuration.
+const (
+	defaultMetricsScheme             = "http"
+	defaultMetricsPath               = "/metrics"
+	defaultMetricsInsecureSkipVerify = true
+)
+
+// metricsDatasourceParams holds the configuration parameters for the metrics data source plugin.
+// These values can be specified in the EndpointPickerConfig under the plugin's `parameters` field.
 type metricsDatasourceParams struct {
 	// Scheme defines the protocol scheme used in metrics retrieval (e.g., "http").
 	Scheme string `json:"scheme"`
@@ -60,68 +68,72 @@ func MetricsDataSourceFactory(name string, parameters json.RawMessage, handle fw
 		name, parseMetrics, PrometheusMetricType)
 }
 
-// Names of CLI flags in main
+// These flags are registered in options.go (server package) and marked as deprecated there.
+// They are kept for one release cycle to give users time to migrate their configuration
+// to the EndpointPickerConfig `parameters` field (metricsDatasourceParams).
+// They will be removed in a future release.
 //
-// TODO:
-//
-//  1. Consider having a cli package with all flag names and constants?
-//     Can't use values from runserver as this creates an import cycle with datalayer.
-//     Given that relevant issues/PRs have been closed so may be able to remove the cycle?
-//     Comment from runserver package (regarding TestPodMetricsClient *backendmetrics.FakePodMetricsClient)
-//     This should only be used in tests. We won't need this once we do not inject metrics in the tests.
-//     TODO:(https://github.com/kubernetes-sigs/gateway-api-inference-extension/issues/432) Cleanup
-//
-//  2. Deprecation notice on these flags being moved to the configuration file
+// TODO: Remove these constants and defaultDataSourceConfigParams() once the deprecated flags
+// are removed from options.go.
+// Note: these flag names are duplicated here (rather than imported from the server package)
+// to avoid an import cycle between the datalayer plugin and the server/runserver packages.
 const (
 	modelServerMetricsPathFlag               = "model-server-metrics-path"
 	modelServerMetricsSchemeFlag             = "model-server-metrics-scheme"
 	modelServerMetricsInsecureSkipVerifyFlag = "model-server-metrics-https-insecure-skip-verify"
 )
 
-// return the default configuration state. The defaults are populated from
-// existing command line flags.
+// DataSource parameters values - Priority (lowest → highest):
+//  1. Built-in defaults (defaultMetricsScheme / defaultMetricsPath / defaultMetricsInsecureSkipVerify)
+//  2. Deprecated CLI flag value (when the flag is registered and has been set by the operator)
+//  3. Explicit plugin `parameters` in EndpointPickerConfig
 func defaultDataSourceConfigParams() (*metricsDatasourceParams, error) {
-	cfg := &metricsDatasourceParams{}
+	cfg := &metricsDatasourceParams{
+		Scheme:             defaultMetricsScheme,
+		Path:               defaultMetricsPath,
+		InsecureSkipVerify: defaultMetricsInsecureSkipVerify,
+	}
 
-	scheme, err := fromStringFlag(modelServerMetricsSchemeFlag)
-	if err != nil {
-		return nil, err
+	if scheme, ok := fromStringFlag(modelServerMetricsSchemeFlag); ok {
+		cfg.Scheme = scheme
 	}
-	cfg.Scheme = scheme
 
-	path, err := fromStringFlag(modelServerMetricsPathFlag)
-	if err != nil {
-		return nil, err
+	if path, ok := fromStringFlag(modelServerMetricsPathFlag); ok {
+		cfg.Path = path
 	}
-	cfg.Path = path
 
-	insecure, err := fromBoolFlag(modelServerMetricsInsecureSkipVerifyFlag)
-	if err != nil {
+	if insecure, ok, err := fromBoolFlag(modelServerMetricsInsecureSkipVerifyFlag); err != nil {
 		return nil, err
+	} else if ok {
+		cfg.InsecureSkipVerify = insecure
 	}
-	cfg.InsecureSkipVerify = insecure
 
 	return cfg, nil
 }
 
-func fromStringFlag(name string) (string, error) {
-	f := pflag.Lookup(name)
+// fromStringFlag returns the value of a registered pflag string flag.
+// The second return value is false when the flag is not registered; no error is returned in that case.
+func fromStringFlag(name string) (string, bool) {
+	f := flag.Lookup(name)
 	if f == nil {
-		return "", fmt.Errorf("flag not found: %s", name)
+		return "", false
 	}
-	return f.Value.String(), nil
+	return f.Value.String(), true
 }
 
-func fromBoolFlag(name string) (bool, error) {
-	f := pflag.Lookup(name)
+// fromBoolFlag returns the value of a registered pflag bool flag.
+// The second return value is false when the flag is not registered; no error is returned in that case.
+// An error is returned only when the flag exists but its value cannot be parsed as a bool.
+func fromBoolFlag(name string) (bool, bool, error) {
+	f := flag.Lookup(name)
 	if f == nil {
-		return false, fmt.Errorf("flag not found: %s", name)
+		return false, false, nil
 	}
 	b, err := strconv.ParseBool(f.Value.String())
 	if err != nil {
-		return false, fmt.Errorf("invalid bool flag %q: %w", name, err)
+		return false, false, fmt.Errorf("invalid bool flag %q: %w", name, err)
 	}
-	return b, nil
+	return b, true, nil
 }
 
 func parseMetrics(data io.Reader) (any, error) {

pkg/epp/server/options.go

@@ -147,13 +147,16 @@ func (opts *Options) AddFlags(fs *pflag.FlagSet) {
 		"Disables respecting the x-gateway-destination-endpoint-subset metadata for dispatching requests in EPP.")
 	fs.StringVar(&opts.ModelServerMetricsScheme, "model-server-metrics-scheme", opts.ModelServerMetricsScheme,
 		"Protocol scheme used in scraping metrics from endpoints.")
+	_ = fs.MarkDeprecated("model-server-metrics-scheme", "This flag is deprecated. Configure via EndpointPickerConfig data layer plugin parameters instead.")
 	fs.StringVar(&opts.ModelServerMetricsPath, "model-server-metrics-path", opts.ModelServerMetricsPath,
 		"URL path used in scraping metrics from endpoints.")
+	_ = fs.MarkDeprecated("model-server-metrics-path", "This flag is deprecated. Configure via EndpointPickerConfig data layer plugin parameters instead.")
 	fs.IntVar(&opts.ModelServerMetricsPort, "model-server-metrics-port", opts.ModelServerMetricsPort,
 		"Port to scrape metrics from endpoints. Set to the InferencePool.Spec.TargetPorts[0].Number if not defined.")
 	_ = fs.MarkDeprecated("model-server-metrics-port", "This flag is deprecated and will be removed in a future release.")
 	fs.BoolVar(&opts.ModelServerMetricsHTTPSInsecure, "model-server-metrics-https-insecure-skip-verify", opts.ModelServerMetricsHTTPSInsecure,
 		"Disable certificate verification when using 'https' scheme for 'model-server-metrics-scheme'.")
+	_ = fs.MarkDeprecated("model-server-metrics-https-insecure-skip-verify", "This flag is deprecated. Configure via EndpointPickerConfig data layer plugin parameters instead.")
 	fs.DurationVar(&opts.RefreshMetricsInterval, "refresh-metrics-interval", opts.RefreshMetricsInterval, "Interval to refresh metrics.")
 	fs.DurationVar(&opts.RefreshPrometheusMetricsInterval, "refresh-prometheus-metrics-interval", opts.RefreshPrometheusMetricsInterval,
 		"Interval to flush Prometheus metrics.")

site-src/implementations/model-servers.md

@@ -80,8 +80,8 @@ kind: EndpointPickerConfig
 featureGates:
 - dataLayer
 plugins:
-- name: model-server-protocol-metrics
-  type: model-server-protocol-metrics
+- name: core-metrics-extractor
+  type: core-metrics-extractor
   parameters:
     defaultEngine: "sglang"  # Pods without engine label will use SGLang metrics
 ```
@@ -96,8 +96,8 @@ kind: EndpointPickerConfig
 featureGates:
 - dataLayer
 plugins:
-- name: model-server-protocol-metrics
-  type: model-server-protocol-metrics
+- name: core-metrics-extractor
+  type: core-metrics-extractor
   parameters:
     engineLabelKey: "inference.networking.k8s.io/engine-type"  # Pod label key (optional, this is the default)
     defaultEngine: "vllm"  # Which engine to use for Pods without engine label