fix(client): fix client Get call done in BD update (#648)

* fix(client): fix client Get call done in BD update

use empty object instead of deepcopy object in Get() call. This
is done so that empty fields returned from API server are not filled
in from the deepcopy object

Signed-off-by: Akhil Mohan <akhil.mohan@mayadata.io>

* Update pkg/epoll/epoll.go

Use logging level 4

Signed-off-by: Aditya Jain <aditya.jainadityajain.jain@gmail.com>

Co-authored-by: Aditya Jain <aditya.jainadityajain.jain@gmail.com>

Author: akhilerm

changelogs/unreleased/648-akhilerm

@@ -0,0 +1 @@
+update get call to use empty object instead of deepcopy object while updating the resources

cmd/ndm_daemonset/controller/blockdevicestore.go

@@ -88,15 +88,15 @@ func (c *Controller) UpdateBlockDevice(blockDevice apis.BlockDevice, oldBlockDev
 
 	blockDeviceCopy := blockDevice.DeepCopy()
 	if oldBlockDevice == nil {
-		oldBlockDevice = blockDevice.DeepCopy()
+		oldBlockDevice = &apis.BlockDevice{}
 		err = c.Clientset.Get(context.TODO(), client.ObjectKey{
-			Namespace: oldBlockDevice.Namespace,
-			Name:      oldBlockDevice.Name}, oldBlockDevice)
+			Namespace: blockDeviceCopy.Namespace,
+			Name:      blockDeviceCopy.Name}, oldBlockDevice)
 		if err != nil {
 			klog.Errorf("eventcode=%s msg=%s : %v, err:%v rname=%v",
 				"ndm.blockdevice.update.failure",
 				"Failed to update block device : unable to get blockdevice object",
-				oldBlockDevice.ObjectMeta.Name, err, blockDeviceCopy.ObjectMeta.Name)
+				blockDeviceCopy.ObjectMeta.Name, err, blockDeviceCopy.ObjectMeta.Name)
 			return err
 		}
 	}
@@ -327,6 +327,9 @@ func mergeMetadata(newMetadata, oldMetadata metav1.ObjectMeta) metav1.ObjectMeta
 
 	// Patch older label with new label. If there is a new key then it will be added
 	// if it is an existing key then value will be overwritten with value from new label
+	if oldMetadata.Labels == nil {
+		oldMetadata.Labels = make(map[string]string)
+	}
 	for key, value := range newMetadata.Labels {
 		oldMetadata.Labels[key] = value
 	}

pkg/epoll/epoll.go

@@ -20,6 +20,8 @@ import (
 	"errors"
 	"os"
 	"syscall"
+
+	"k8s.io/klog"
 )
 
 const (
@@ -189,6 +191,7 @@ func (e *Epoll) dispatchEvent(ev *syscall.EpollEvent) {
 	if !ok {
 		return
 	}
+	klog.V(4).Infof("epoll event for file %s dispatched", w.FileName)
 
 	e.eventChan <- Event{
 		fileName: w.FileName,
@@ -200,7 +203,9 @@ func (e *Epoll) listen() {
 	events := make([]syscall.EpollEvent, 2)
 	for e.active {
 		// TODO: Handle errors here
+		klog.V(4).Info("waiting for epoll events...")
 		count, _ := syscall.EpollWait(e.epfd, events, timeout)
+		klog.V(4).Infof("received %d events from epoll. dispatching...", count)
 		for i := 0; e.active && i < count; i++ {
 			e.dispatchEvent(&events[i])
 		}