Add the DisableDrain when running one a single node

Signed-off-by: Sebastian Sch <sebassch@gmail.com>

controllers/sriovoperatorconfig_controller.go

@@ -78,6 +78,11 @@ func (r *SriovOperatorConfigReconciler) Reconcile(ctx context.Context, req ctrl.
 		Name: constants.DEFAULT_CONFIG_NAME, Namespace: namespace}, defaultConfig)
 	if err != nil {
 		if errors.IsNotFound(err) {
+			singleNode, err := utils.IsSingleNodeCluster(r.Client)
+			if err != nil {
+				return reconcile.Result{}, fmt.Errorf("Couldn't check the anount of nodes in the cluster")
+			}
+
 			// Default Config object not found, create it.
 			defaultConfig.SetNamespace(namespace)
 			defaultConfig.SetName(constants.DEFAULT_CONFIG_NAME)
@@ -86,7 +91,9 @@ func (r *SriovOperatorConfigReconciler) Reconcile(ctx context.Context, req ctrl.
 				EnableOperatorWebhook:    func() *bool { b := enableAdmissionController; return &b }(),
 				ConfigDaemonNodeSelector: map[string]string{},
 				LogLevel:                 2,
+				DisableDrain:             singleNode,
 			}
+
 			err = r.Create(context.TODO(), defaultConfig)
 			if err != nil {
 				logger.Error(err, "Failed to create default Operator Config", "Namespace",

main.go

@@ -232,13 +232,20 @@ func createDefaultOperatorConfig(cfg *rest.Config) error {
 	if err != nil {
 		return fmt.Errorf("Couldn't create client: %v", err)
 	}
+
+	singleNode, err := utils.IsSingleNodeCluster(c)
+	if err != nil {
+		return fmt.Errorf("Couldn't check the anount of nodes in the cluster")
+	}
+
 	enableAdmissionController := os.Getenv("ENABLE_ADMISSION_CONTROLLER") == "true"
 	config := &sriovnetworkv1.SriovOperatorConfig{
 		Spec: sriovnetworkv1.SriovOperatorConfigSpec{
 			EnableInjector:           func() *bool { b := enableAdmissionController; return &b }(),
 			EnableOperatorWebhook:    func() *bool { b := enableAdmissionController; return &b }(),
 			ConfigDaemonNodeSelector: map[string]string{},
 			LogLevel:                 2,
+			DisableDrain:             singleNode,
 		},
 	}
 	name := "default"

pkg/daemon/daemon.go

@@ -498,25 +498,27 @@ func (dn *Daemon) nodeStateSyncHandler(generation int64) error {
 	}
 
 	if reqDrain {
-		ctx, cancel := context.WithCancel(context.TODO())
-		defer cancel()
-
-		glog.Infof("nodeStateSyncHandler(): get drain lock for sriov daemon")
-		done := make(chan bool)
-		go dn.getDrainLock(ctx, done)
-		<-done
+		if !dn.disableDrain {
+			ctx, cancel := context.WithCancel(context.TODO())
+			defer cancel()
 
-		glog.Infof("nodeStateSyncHandler(): pause MCP")
-		if err := dn.pauseMCP(); err != nil {
-			return err
+			glog.Infof("nodeStateSyncHandler(): get drain lock for sriov daemon")
+			done := make(chan bool)
+			go dn.getDrainLock(ctx, done)
+			<-done
 		}
 
-		if !dn.disableDrain {
-			glog.Info("nodeStateSyncHandler(): drain node")
-			if err := dn.drainNode(); err != nil {
+		if utils.ClusterType == utils.ClusterTypeOpenshift {
+			glog.Infof("nodeStateSyncHandler(): pause MCP")
+			if err := dn.pauseMCP(); err != nil {
 				return err
 			}
 		}
+
+		glog.Info("nodeStateSyncHandler(): drain node")
+		if err := dn.drainNode(); err != nil {
+			return err
+		}
 	}
 
 	if !reqReboot {
@@ -819,14 +821,9 @@ func (dn *Daemon) getDrainLock(ctx context.Context, done chan bool) {
 }
 
 func (dn *Daemon) pauseMCP() error {
-	glog.Info("pauseMCP(): check if pausing MCP is possible")
+	glog.Info("pauseMCP(): pausing MCP")
 	var err error
 
-	if utils.ClusterType != utils.ClusterTypeOpenshift {
-		glog.Infof("pauseMCP(): skipping MCP pause as the cluster is not an openshift cluster")
-		return nil
-	}
-
 	mcpInformerFactory := mcfginformers.NewSharedInformerFactory(dn.mcClient,
 		time.Second*30,
 	)
@@ -913,6 +910,11 @@ func (dn *Daemon) pauseMCP() error {
 }
 
 func (dn *Daemon) drainNode() error {
+	if dn.disableDrain {
+		glog.Info("drainNode(): disable drain is true skipping drain")
+		return nil
+	}
+
 	glog.Info("drainNode(): Update prepared")
 	var err error
 

pkg/utils/cluster.go

@@ -0,0 +1,26 @@
+package utils
+
+import (
+	"context"
+
+	"github.com/golang/glog"
+
+	corev1 "k8s.io/api/core/v1"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+)
+
+func IsSingleNodeCluster(c client.Client) (bool, error) {
+	nodeList := &corev1.NodeList{}
+	err := c.List(context.TODO(), nodeList)
+	if err != nil {
+		glog.Errorf("IsSingleNodeCluster(): Failed to list nodes: %v", err)
+		return false, err
+	}
+
+	if len(nodeList.Items) == 1 {
+		glog.Infof("IsSingleNodeCluster(): one node found in the cluster")
+		return true, nil
+	}
+
+	return false, nil
+}