more flow control

Author: LukeAVanDrie

pkg/epp/flowcontroller/config.go

@@ -20,8 +20,14 @@ import (
 	"fmt"
 	"time"
 
+	"github.com/go-logr/logr"
 	"sigs.k8s.io/controller-runtime/pkg/log"
 	v1alpha2 "sigs.k8s.io/gateway-api-inference-extension/api/v1alpha2"
+	interd "sigs.k8s.io/gateway-api-inference-extension/pkg/epp/flowcontroller/plugins/dispatch/interflow"
+	intrad "sigs.k8s.io/gateway-api-inference-extension/pkg/epp/flowcontroller/plugins/dispatch/intraflow"
+	interp "sigs.k8s.io/gateway-api-inference-extension/pkg/epp/flowcontroller/plugins/preemption/interflow"
+	intrap "sigs.k8s.io/gateway-api-inference-extension/pkg/epp/flowcontroller/plugins/preemption/intraflow"
+	"sigs.k8s.io/gateway-api-inference-extension/pkg/epp/flowcontroller/plugins/queue"
 	"sigs.k8s.io/gateway-api-inference-extension/pkg/epp/flowcontroller/types"
 	envutil "sigs.k8s.io/gateway-api-inference-extension/pkg/epp/util/env"
 )
@@ -99,6 +105,49 @@ type FlowControllerConfig struct {
 	CustomFairnessPolicies map[v1alpha2.Criticality]types.FairnessPolicy
 	// TODO: Add CustomPreemptionStrategies map[v1alpha2.Criticality]types.PreemptionStrategy
 	// if similar custom injection is desired for preemption strategies.
+
+	PriorityBands []PriorityBandConfig
+}
+
+// PriorityBandConfig defines the configuration for a single priority band.
+type PriorityBandConfig struct {
+	PriorityLevel             uint
+	PriorityName              string
+	InterFlowDispatchPolicy   interd.RegisteredInterFlowDispatchPolicyName
+	InterFlowPreemptionPolicy interp.RegisteredInterFlowPreemptionPolicyName
+	IntraFlowDispatchPolicy   intrad.RegisteredIntraFlowDispatchPolicyName
+	IntraFlowPreemptionPolicy intrap.RegisteredIntraFlowPreemptionPolicyName
+	QueueType                 queue.RegisteredQueueName
+	// TODO: Add MaxBytes for this band here, replacing parts of MaxBytesPerCriticality.
+}
+
+// validateAndApplyDefaults validates and applies defaults for a single PriorityBandConfig.
+func (pbc *PriorityBandConfig) validateAndApplyDefaults(logger logr.Logger) error {
+	if pbc.PriorityName == "" {
+		return fmt.Errorf("PriorityName cannot be empty for priority level %d", pbc.PriorityLevel)
+	}
+	bandLogger := logger.WithValues("priority", pbc.PriorityLevel, "priorityName", pbc.PriorityName)
+	if pbc.InterFlowDispatchPolicy == "" {
+		bandLogger.V(1).Info("InterFlowDispatchPolicy is empty, using default", "defaultPolicy", interd.BestHeadPriorityScoreDispatchPolicyName)
+		pbc.InterFlowDispatchPolicy = interd.BestHeadPriorityScoreDispatchPolicyName
+	}
+	if pbc.InterFlowPreemptionPolicy == "" {
+		bandLogger.V(1).Info("InterFlowPreemptionPolicy is empty, using default", "defaultPolicy", interp.RoundRobinPreemptionPolicyName)
+		pbc.InterFlowPreemptionPolicy = interp.RoundRobinPreemptionPolicyName
+	}
+	if pbc.IntraFlowDispatchPolicy == "" {
+		bandLogger.V(1).Info("IntraFlowDispatchPolicy is empty, using default", "defaultPolicy", intrad.FCFSDispatchPolicyName)
+		pbc.IntraFlowDispatchPolicy = intrad.FCFSDispatchPolicyName
+	}
+	if pbc.IntraFlowPreemptionPolicy == "" {
+		bandLogger.V(1).Info("IntraFlowPreemptionPolicy is empty, using default", "defaultPolicy", intrap.TailPreemptionPolicyName)
+		pbc.IntraFlowPreemptionPolicy = intrap.TailPreemptionPolicyName
+	}
+	if pbc.QueueType == "" {
+		bandLogger.V(1).Info("QueueType is empty, using default", "defaultQueue", queue.ListQueueName)
+		pbc.QueueType = queue.ListQueueName
+	}
+	return nil
 }
 
 // validateAndApplyDefaults validates the provided config and assigns default
@@ -144,6 +193,15 @@ func (cfg *FlowControllerConfig) validateAndApplyDefaults() error {
 		}
 	}
 
+	// Validate and apply defaults for each priority band.
+	// This assumes PriorityBands is the source of truth for band-specific policies.
+	// The top-level policy strings might become deprecated or used as global defaults if a band doesn't specify.
+	logger := log.Log.WithName("flow-controller-config-validation") // Use a local logger for this phase
+	for i := range cfg.PriorityBands {
+		if err := cfg.PriorityBands[i].validateAndApplyDefaults(logger); err != nil {
+			return fmt.Errorf("invalid config for priority band %s (level %d): %w", cfg.PriorityBands[i].PriorityName, cfg.PriorityBands[i].PriorityLevel, err)
+		}
+	}
 	return nil
 }