OPTIM/MINOR: watch only specific configmaps

Author: oktalz

pkg/k8s/main.go

@@ -33,6 +33,8 @@ import (
 	k8ssync "github.com/haproxytech/kubernetes-ingress/pkg/k8s/sync"
 	"github.com/haproxytech/kubernetes-ingress/pkg/utils"
 	crdclientset "k8s.io/apiextensions-apiserver/pkg/client/clientset/clientset"
+	"k8s.io/apimachinery/pkg/fields"
+
 	errGw "k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"sigs.k8s.io/controller-runtime/pkg/client"
@@ -155,7 +157,7 @@ func (k k8s) MonitorChanges(eventChan chan k8ssync.SyncDataEvent, stop chan stru
 	informersSynced := &[]cache.InformerSynced{}
 	k.runPodInformer(eventChan, stop, informersSynced)
 	for _, namespace := range k.whiteListedNS {
-		k.runInformers(eventChan, stop, namespace, informersSynced)
+		k.runInformers(eventChan, stop, namespace, informersSynced, osArgs)
 		k.runCRInformers(eventChan, stop, namespace, informersSynced, k.crs)
 		if gatewayAPIInstalled {
 			k.runInformersGwAPI(eventChan, stop, namespace, informersSynced)
@@ -206,7 +208,21 @@ func (k k8s) runCRInformers(eventChan chan k8ssync.SyncDataEvent, stop chan stru
 	}
 }
 
-func (k k8s) runInformers(eventChan chan k8ssync.SyncDataEvent, stop chan struct{}, namespace string, informersSynced *[]cache.InformerSynced) {
+func (k k8s) runConfigMapInformers(eventChan chan k8ssync.SyncDataEvent, stop chan struct{}, informersSynced *[]cache.InformerSynced, configMap utils.NamespaceValue) {
+	if configMap.Name != "" {
+		fieldSelector := fields.OneTermEqualSelector("metadata.name", configMap.Name).String()
+		factory := k8sinformers.NewSharedInformerFactoryWithOptions(k.builtInClient, k.cacheResyncPeriod, k8sinformers.WithNamespace(configMap.Namespace),
+			k8sinformers.WithTweakListOptions(func(opts *metav1.ListOptions) {
+				opts.FieldSelector = fieldSelector
+			}))
+
+		cmi := k.getConfigMapInformer(eventChan, factory)
+		go cmi.Run(stop)
+		*informersSynced = append(*informersSynced, cmi.HasSynced)
+	}
+}
+
+func (k k8s) runInformers(eventChan chan k8ssync.SyncDataEvent, stop chan struct{}, namespace string, informersSynced *[]cache.InformerSynced, osArgs utils.OSArgs) {
 	factory := k8sinformers.NewSharedInformerFactoryWithOptions(k.builtInClient, k.cacheResyncPeriod, k8sinformers.WithNamespace(namespace))
 	// Core.V1 Resources
 	nsi := k.getNamespaceInfomer(eventChan, factory)
@@ -215,10 +231,12 @@ func (k k8s) runInformers(eventChan chan k8ssync.SyncDataEvent, stop chan struct
 	go svci.Run(stop)
 	seci := k.getSecretInformer(eventChan, factory)
 	go seci.Run(stop)
-	cmi := k.getConfigMapInformer(eventChan, factory)
-	go cmi.Run(stop)
+	*informersSynced = append(*informersSynced, svci.HasSynced, nsi.HasSynced, seci.HasSynced)
 
-	*informersSynced = append(*informersSynced, svci.HasSynced, nsi.HasSynced, seci.HasSynced, cmi.HasSynced)
+	k.runConfigMapInformers(eventChan, stop, informersSynced, osArgs.ConfigMap)
+	k.runConfigMapInformers(eventChan, stop, informersSynced, osArgs.ConfigMapTCPServices)
+	k.runConfigMapInformers(eventChan, stop, informersSynced, osArgs.ConfigMapErrorFiles)
+	k.runConfigMapInformers(eventChan, stop, informersSynced, osArgs.ConfigMapPatternFiles)
 
 	// Ingress and IngressClass Resources
 	ii, ici := k.getIngressInformers(eventChan, factory)

pkg/store/events.go

@@ -212,7 +212,9 @@ func (k *K8s) EventConfigMap(ns *Namespace, data *ConfigMap) (updateRequired boo
 		}
 		*cm = *data
 		cm.Loaded = true
-		updateRequired = true
+		if !cm.Empty() {
+			updateRequired = true
+		}
 		logger.Debugf("configmap '%s/%s' processed", cm.Namespace, cm.Name)
 	case MODIFIED:
 		if cm.Equal(data) {
@@ -224,7 +226,9 @@ func (k *K8s) EventConfigMap(ns *Namespace, data *ConfigMap) (updateRequired boo
 	case DELETED:
 		cm.Loaded = false
 		cm.Annotations = map[string]string{}
-		updateRequired = true
+		if !cm.Empty() {
+			updateRequired = true
+		}
 		logger.Debugf("configmap '%s/%s' deleted", cm.Namespace, cm.Name)
 	}
 	return updateRequired

pkg/store/types-equal.go

@@ -77,6 +77,17 @@ func (a *ConfigMap) Equal(b *ConfigMap) bool {
 	return true
 }
 
+// Empty checks if configmap is empty
+func (a *ConfigMap) Empty() bool {
+	if a == nil {
+		return true
+	}
+	if len(a.Annotations) == 0 {
+		return true
+	}
+	return false
+}
+
 // Equal compares two secrets, ignores statuses and old values
 func (a *Secret) Equal(b *Secret) bool {
 	if a == nil || b == nil {