add reconcile-reources flag

pkg/config/config.go

@@ -64,6 +64,7 @@ const (
 	flagReconcileDefaultMaxConcurrency  = "reconcile-default-max-concurrent-syncs"
 	flagReconcileResourceMaxConcurrency = "reconcile-resource-max-concurrent-syncs"
 	flagFeatureGates                    = "feature-gates"
+	flagReconcileResources              = "reconcile-resources"
 	envVarAWSRegion                     = "AWS_REGION"
 )
 
@@ -104,6 +105,7 @@ type Config struct {
 	ReconcileResourceResyncSeconds  []string
 	ReconcileDefaultMaxConcurrency  int
 	ReconcileResourceMaxConcurrency []string
+	ReconcileResources              string
 	// TODO(a-hilaly): migrate to k8s.io/component-base and implement a proper parser for feature gates.
 	FeatureGates    featuregate.FeatureGates
 	featureGatesRaw string
@@ -250,6 +252,11 @@ func (cfg *Config) BindFlags() {
 			"Valid keys are feature names and valid values are 'true' or 'false'."+
 			"Available features: "+strings.Join(featuregate.GetDefaultFeatureGates().GetFeatureNames(), ", "),
 	)
+	flag.StringVar(
+		&cfg.ReconcileResources, flagReconcileResources,
+		"",
+		"A comma-separated list of resource kinds to reconcile. If unspecified, all resources will be reconciled.",
+	)
 }
 
 // SetupLogger initializes the logger used in the service controller
@@ -389,6 +396,12 @@ func (cfg *Config) validateReconcileConfigResources(supportedGVKs []schema.Group
 			return fmt.Errorf("invalid value for flag '%s': %v", flagReconcileResourceMaxConcurrency, err)
 		}
 	}
+
+	// Also validate the resource filter settings
+	if err := cfg.validateReconcileResources(validResourceNames); err != nil {
+		return err
+	}
+
 	return nil
 }
 
@@ -564,3 +577,56 @@ func parseFeatureGates(featureGatesRaw string) (map[string]bool, error) {
 
 	return featureGatesMap, nil
 }
+
+// GetReconcileResources returns a slice of resource kinds that should be reconciled.
+func (cfg *Config) GetReconcileResources() ([]string, error) {
+	return parseReconcileResourcesString(cfg.ReconcileResources)
+}
+
+// parseReconcileResourcesString parses the reconcileResources flag and returns a slice
+// of resource kinds to reconcile.
+func parseReconcileResourcesString(resources string) ([]string, error) {
+	resources = strings.TrimSpace(resources)
+	if resources == "" {
+		return nil, nil
+	}
+
+	visited := make(map[string]bool)
+	resourceKinds := []string{}
+
+	for _, kind := range strings.Split(resources, ",") {
+		kind = strings.TrimSpace(kind)
+		if kind == "" {
+			return nil, fmt.Errorf("invalid resource kind: empty kind")
+		}
+		if _, ok := visited[kind]; ok {
+			return nil, fmt.Errorf("duplicate resource kind '%s'", kind)
+		}
+		visited[kind] = true
+		resourceKinds = append(resourceKinds, kind)
+	}
+	return resourceKinds, nil
+}
+
+// validateReconcileResources validates that the specified resource kinds are supported by the controller.
+func (cfg *Config) validateReconcileResources(validResourceNames []string) error {
+	resources, err := cfg.GetReconcileResources()
+	if err != nil {
+		return fmt.Errorf("invalid value for flag '%s': %v", flagReconcileResources, err)
+	}
+	if len(resources) == 0 {
+		return nil
+	}
+
+	for _, resource := range resources {
+		if !ackutil.InStrings(resource, validResourceNames) {
+			return fmt.Errorf(
+				"invalid value for flag '%s': resource kind '%s' is not supported by this controller. Valid resource kinds are: %s",
+				flagReconcileResources,
+				resource,
+				strings.Join(validResourceNames, ", "),
+			)
+		}
+	}
+	return nil
+}

pkg/runtime/service_controller.go

@@ -34,6 +34,7 @@ import (
 	ackmetrics "github.com/aws-controllers-k8s/runtime/pkg/metrics"
 	ackrtcache "github.com/aws-controllers-k8s/runtime/pkg/runtime/cache"
 	acktypes "github.com/aws-controllers-k8s/runtime/pkg/types"
+	ackutil "github.com/aws-controllers-k8s/runtime/pkg/util"
 )
 
 const (
@@ -271,7 +272,33 @@ func (c *serviceController) BindControllerManager(mgr ctrlrt.Manager, cfg ackcfg
 		c.fieldExportReconciler = rec
 	}
 
-	for _, rmf := range c.rmFactories {
+	// Get the list of resources to reconcile from the config
+	reconcileResources, err := cfg.GetReconcileResources()
+	if err != nil {
+		return fmt.Errorf("error parsing reconcile resources: %v", err)
+	}
+
+	if len(reconcileResources) == 0 {
+		c.log.Info("No resources? Did they all go on vacation? Defaulting to reconciling all resources.")
+	}
+	// Filter the resource manager factories
+	filteredRMFs := c.rmFactories
+	if len(reconcileResources) > 0 {
+		filteredRMFs = make(map[string]acktypes.AWSResourceManagerFactory)
+		for key, rmf := range c.rmFactories {
+			rd := rmf.ResourceDescriptor()
+			resourceKind := rd.GroupVersionKind().Kind
+
+			if ackutil.InStrings(resourceKind, reconcileResources) {
+				filteredRMFs[key] = rmf
+				c.log.Info("including reconciler for resource kind", "kind", resourceKind)
+			} else {
+				c.log.Info("excluding reconciler for resource kind", "kind", resourceKind, "reason", "not in reconcile-resources flag")
+			}
+		}
+	}
+
+	for _, rmf := range filteredRMFs {
 		rec := NewReconciler(c, rmf, c.log, cfg, c.metrics, cache)
 		if err := rec.BindControllerManager(mgr); err != nil {
 			return err