a global LevelVar:

	var programLevel = new(slog.LevelVar) // Info by default

Then use the LevelVar to construct a handler, and make it the default:

	h := slog.NewJSONHandler(os.Stderr, &slog.HandlerOptions{Level: programLevel})
	slog.SetDefault(slog.New(h))

Now the program can change its logging level with a single statement:

	programLevel.Set(slog.LevelDebug)

# Groups

			klog.V(4).Infof("%s: write required for target directory %v", w.logContext, w.targetDir)
		}
	}

	if shouldWrite {
		// (5)
		tsDir, err := w.newTimestampDir()
		if err != nil {
			klog.V(4).Infof("%s: error creating new ts data directory: %v", w.logContext, err)
			return err
		}
		tsDirName := filepath.Base(tsDir)

		// (6)
		if err = w.writePayloadToDir(cleanPayload, tsDir); err != nil {

func removeMountDir(plug *csiPlugin, mountPath string) error {
	klog.V(4).Info(log("removing mount path [%s]", mountPath))

	mnt, err := isDirMounted(plug, mountPath)
	if err != nil {
		return err
	}
	if !mnt {
		klog.V(4).Info(log("dir not mounted, deleting it [%s]", mountPath))
		if err := os.Remove(mountPath); err != nil && !os.IsNotExist(err) {
			return errors.New(log("failed to remove dir [%s]: %v", mountPath, err))
		}

		if _, present := spec.VolumeLabels[k]; present {
			klog.Warningf("not saving annotation: %s=%s in spec labels due to an existing key", k, v)
			continue
		}
		spec.VolumeLabels[k] = v
	}

	volumeID, err := driver.Create(locator, source, spec)
	if err != nil {
		klog.Errorf("Error creating Portworx Volume : %v", err)
		return "", 0, nil, err
	}

	return true
}

func (c *Controller) processPVC(ctx context.Context, pvcNamespace, pvcName string) error {
	logger := klog.FromContext(ctx)
	logger.V(4).Info("Processing PVC", "PVC", klog.KRef(pvcNamespace, pvcName))
	startTime := time.Now()
	defer func() {
		logger.V(4).Info("Finished processing PVC", "PVC", klog.KRef(pvcNamespace, pvcName), "duration", time.Since(startTime))
	}()

	for i := 0; i < retries; i++ {
		if i > 0 {
			klog.V(1).Infof("[etcd] Waiting %v until next retry\n", retryInterval)
			time.Sleep(retryInterval)
		}
		klog.V(2).Infof("[etcd] attempting to see if all cluster endpoints (%s) are available %d/%d", c.Endpoints, i+1, retries)
		_, err := c.getClusterStatus()
		if err != nil {
			switch err {
			case context.DeadlineExceeded:
				klog.V(1).Infof("[etcd] Attempt timed out")
			default:

}

func (gcc *PodGCController) gc(ctx context.Context) {
	pods, err := gcc.podLister.List(labels.Everything())
	if err != nil {
		klog.FromContext(ctx).Error(err, "Error while listing all pods")
		return
	}
	nodes, err := gcc.nodeLister.List(labels.Everything())
	if err != nil {
		klog.FromContext(ctx).Error(err, "Error while listing all nodes")
		return
	}
	if gcc.terminatedPodThreshold > 0 {

		// Updates RunContainerOptions.Envs.
		for k, v := range resp.Envs {
			if e, ok := envsMap[k]; ok {
				klog.V(4).InfoS("Skip existing env", "envKey", k, "envValue", v)
				if e != v {
					klog.ErrorS(nil, "Environment variable has conflicting setting", "envKey", k, "expected", v, "got", e)
				}
				continue
			}
			klog.V(4).InfoS("Add env", "envKey", k, "envValue", v)
			envsMap[k] = v

		if err != nil {
			// nolint:logcheck // Not using the result of klog.V inside the
			// if branch is okay, we just use it to determine whether the
			// additional "podStatus" key and its value should be added.
			if klog.V(6).Enabled() {
				klog.ErrorS(err, "Evented PLEG: error generating pod status from the received event", "podUID", podID, "podStatus", status)
			} else {

				return err
			}
			switch {
			case result.Protected && result.Operation != reconciliation.ReconcileNone:
				klog.Warningf("skipped reconcile-protected clusterrole.%s/%s with missing permissions: %v", rbac.GroupName, clusterRole.Name, result.MissingRules)
			case result.Operation == reconciliation.ReconcileUpdate:
				klog.V(2).Infof("updated clusterrole.%s/%s with additional permissions: %v", rbac.GroupName, clusterRole.Name, result.MissingRules)