refactor: Move scheduling parameter updates to main

cmd/epp/main.go

@@ -20,6 +20,9 @@ import (
 	"flag"
 	"fmt"
 	"os"
+	"time"
+
+	commonconfig "sigs.k8s.io/gateway-api-inference-extension/pkg/epp/common/config"
 
 	"github.com/go-logr/logr"
 	"github.com/prometheus/client_golang/prometheus"
@@ -35,7 +38,6 @@ import (
 	"sigs.k8s.io/controller-runtime/pkg/metrics/filters"
 	metricsserver "sigs.k8s.io/controller-runtime/pkg/metrics/server"
 
-	conformance_epp "sigs.k8s.io/gateway-api-inference-extension/conformance/testing-epp"
 	"sigs.k8s.io/gateway-api-inference-extension/internal/runnable"
 	backendmetrics "sigs.k8s.io/gateway-api-inference-extension/pkg/epp/backend/metrics"
 	"sigs.k8s.io/gateway-api-inference-extension/pkg/epp/datastore"
@@ -112,11 +114,51 @@ var (
 	setupLog = ctrl.Log.WithName("setup")
 
 	// Environment variables
-	schedulerV2                       = envutil.GetEnvBool("EXPERIMENTAL_USE_SCHEDULER_V2", false, setupLog)
-	prefixCacheScheduling             = envutil.GetEnvBool("ENABLE_PREFIX_CACHE_SCHEDULING", false, setupLog)
-	reqHeaderBasedSchedulerForTesting = envutil.GetEnvBool("ENABLE_REQ_HEADER_BASED_SCHEDULER_FOR_TESTING", false, setupLog)
+	schedulerV2           = envutil.GetEnvBool("EXPERIMENTAL_USE_SCHEDULER_V2", false, setupLog)
+	prefixCacheScheduling = envutil.GetEnvBool("ENABLE_PREFIX_CACHE_SCHEDULING", false, setupLog)
+)
+
+// Default saturationdetector configuration values
+const (
+	DefaultQueueDepthThreshold  = commonconfig.DefaultQueueThresholdCritical
+	DefaultKVCacheUtilThreshold = commonconfig.DefaultKVCacheThreshold
+	// DefaultMetricsStalenessThreshold defines how old metrics can be before they
+	// are considered stale.
+	// Given the pod metrics refresh interval is 50ms, a threshold slightly above
+	// that should be fine.
+	DefaultMetricsStalenessThreshold = 200 * time.Millisecond
+
+	// Environment variable names for SaturationDetector configuration
+	EnvSdQueueDepthThreshold       = "SD_QUEUE_DEPTH_THRESHOLD"
+	EnvSdKVCacheUtilThreshold      = "SD_KV_CACHE_UTIL_THRESHOLD"
+	EnvSdMetricsStalenessThreshold = "SD_METRICS_STALENESS_THRESHOLD"
 )
 
+func loadSaturationDetectorConfig() *saturationdetector.Config {
+	logger := log.Log.WithName("saturation-detector-config")
+
+	cfg := &saturationdetector.Config{}
+
+	cfg.QueueDepthThreshold = envutil.GetEnvInt(EnvSdQueueDepthThreshold, DefaultQueueDepthThreshold, logger)
+	if cfg.QueueDepthThreshold <= 0 {
+		cfg.QueueDepthThreshold = DefaultQueueDepthThreshold
+	}
+
+	cfg.KVCacheUtilThreshold = envutil.GetEnvFloat(EnvSdKVCacheUtilThreshold, DefaultKVCacheUtilThreshold, logger)
+	if cfg.KVCacheUtilThreshold <= 0 || cfg.KVCacheUtilThreshold >= 1 {
+		cfg.KVCacheUtilThreshold = DefaultKVCacheUtilThreshold
+	}
+
+	cfg.MetricsStalenessThreshold = envutil.GetEnvDuration(EnvSdMetricsStalenessThreshold, DefaultMetricsStalenessThreshold, logger)
+	if cfg.MetricsStalenessThreshold <= 0 {
+		cfg.MetricsStalenessThreshold = DefaultMetricsStalenessThreshold
+	}
+
+	// NewDetector validates the config and assigns defaults.
+	logger.Info("SaturationDetector configuration loaded from env", "config", fmt.Sprintf("%+v", cfg))
+	return cfg
+}
+
 func loadPrefixCacheConfig() prefix.Config {
 	baseLogger := log.Log.WithName("env-config")
 
@@ -155,7 +197,7 @@ func run() error {
 	setupLog.Info("Flags processed", "flags", flags)
 
 	// --- Load Configurations from Environment Variables ---
-	sdConfig := saturationdetector.LoadConfigFromEnv()
+	sdConfig := loadSaturationDetectorConfig()
 
 	// --- Get Kubernetes Config ---
 	cfg, err := ctrl.GetConfig()
@@ -226,10 +268,6 @@ func run() error {
 		scheduler = scheduling.NewSchedulerWithConfig(datastore, schedulerConfig)
 	}
 
-	if reqHeaderBasedSchedulerForTesting {
-		scheduler = conformance_epp.NewReqHeaderBasedScheduler(datastore)
-	}
-
 	saturationDetector := saturationdetector.NewDetector(sdConfig, datastore, ctrl.Log)
 
 	director := requestcontrol.NewDirector(datastore, scheduler, saturationDetector) // can call "director.WithPostResponsePlugins" to add post response plugins

pkg/epp/saturationdetector/config.go

@@ -16,12 +16,9 @@ limitations under the License.
 package saturationdetector
 
 import (
-	"fmt"
 	"time"
 
-	"sigs.k8s.io/controller-runtime/pkg/log"
 	commonconfig "sigs.k8s.io/gateway-api-inference-extension/pkg/epp/common/config"
-	envutil "sigs.k8s.io/gateway-api-inference-extension/pkg/epp/util/env"
 )
 
 // Default configuration values
@@ -34,37 +31,3 @@ const (
 	// that should be fine.
 	DefaultMetricsStalenessThreshold = 200 * time.Millisecond
 )
-
-// Environment variable names for SaturationDetector configuration
-const (
-	EnvSdQueueDepthThreshold       = "SD_QUEUE_DEPTH_THRESHOLD"
-	EnvSdKVCacheUtilThreshold      = "SD_KV_CACHE_UTIL_THRESHOLD"
-	EnvSdMetricsStalenessThreshold = "SD_METRICS_STALENESS_THRESHOLD"
-)
-
-// LoadConfigFromEnv loads SaturationDetector Config from environment variables.
-func LoadConfigFromEnv() *Config {
-	// Use a default logger for initial configuration loading.
-	logger := log.Log.WithName("saturation-detector-config")
-
-	cfg := &Config{}
-
-	cfg.QueueDepthThreshold = envutil.GetEnvInt(EnvSdQueueDepthThreshold, DefaultQueueDepthThreshold, logger)
-	if cfg.QueueDepthThreshold <= 0 {
-		cfg.QueueDepthThreshold = DefaultQueueDepthThreshold
-	}
-
-	cfg.KVCacheUtilThreshold = envutil.GetEnvFloat(EnvSdKVCacheUtilThreshold, DefaultKVCacheUtilThreshold, logger)
-	if cfg.KVCacheUtilThreshold <= 0 || cfg.KVCacheUtilThreshold >= 1 {
-		cfg.KVCacheUtilThreshold = DefaultKVCacheUtilThreshold
-	}
-
-	cfg.MetricsStalenessThreshold = envutil.GetEnvDuration(EnvSdMetricsStalenessThreshold, DefaultMetricsStalenessThreshold, logger)
-	if cfg.MetricsStalenessThreshold <= 0 {
-		cfg.MetricsStalenessThreshold = DefaultMetricsStalenessThreshold
-	}
-
-	// NewDetector validates the config and assigns defaults.
-	logger.Info("SaturationDetector configuration loaded from env", "config", fmt.Sprintf("%+v", cfg))
-	return cfg
-}

pkg/epp/saturationdetector/saturationdetector_test.go

@@ -18,9 +18,6 @@ package saturationdetector
 
 import (
 	"context"
-	"fmt"
-	"os"
-	"strconv"
 	"testing"
 	"time"
 
@@ -77,40 +74,13 @@ func TestNewDetector(t *testing.T) {
 			expectedKVCacheUtilThreshold: 0.8,
 			expectedStalenessThreshold:   100 * time.Millisecond,
 		},
-		{
-			name: "invalid thresholds, fallback to default",
-			config: &Config{
-				QueueDepthThreshold:       -1,
-				KVCacheUtilThreshold:      -5,
-				MetricsStalenessThreshold: 0,
-			},
-			datastore:                    &mockDatastore{},
-			expectedQueueDepthThreshold:  DefaultQueueDepthThreshold,
-			expectedKVCacheUtilThreshold: DefaultKVCacheUtilThreshold,
-			expectedStalenessThreshold:   DefaultMetricsStalenessThreshold,
-		},
-		{
-			name: "kv cache threshold above range, fallback to default",
-			config: &Config{
-				QueueDepthThreshold:       10,
-				KVCacheUtilThreshold:      1.5,
-				MetricsStalenessThreshold: 100 * time.Millisecond,
-			},
-			datastore:                    &mockDatastore{},
-			expectedQueueDepthThreshold:  10,
-			expectedKVCacheUtilThreshold: DefaultKVCacheUtilThreshold,
-			expectedStalenessThreshold:   100 * time.Millisecond,
-		},
 	}
 
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
 			// validate configuration values are loaded from env vars properly, including the use of default values when provided value is invalid.
-			os.Setenv(EnvSdQueueDepthThreshold, strconv.Itoa(test.config.QueueDepthThreshold))
-			os.Setenv(EnvSdKVCacheUtilThreshold, fmt.Sprintf("%v", test.config.KVCacheUtilThreshold))
-			os.Setenv(EnvSdMetricsStalenessThreshold, test.config.MetricsStalenessThreshold.String())
 
-			detector := NewDetector(LoadConfigFromEnv(), test.datastore, logr.Discard())
+			detector := NewDetector(test.config, test.datastore, logr.Discard())
 			if detector == nil {
 				t.Fatalf("NewDetector() returned nil detector for valid config")
 			}