added optional, configurable subscribe options

controller/controller.go

@@ -82,7 +82,7 @@ func initialize() error {
 
 	c.deviceWatcher = nucleus.NewDeviceWatcher(c.pndStore)
 	//TODO: Just an example for testing purposes, remove these calls after complete implementation of subscription handling!
-	c.deviceWatcher.SubToDevices([][]string{{"system", "config", "hostname"}})
+	c.deviceWatcher.SubToDevices([][]string{{"system", "config", "hostname"}}, nil)
 	go func() {
 		time.Sleep(5 * time.Second)
 		c.deviceWatcher.StopAndRemoveAllDeviceSubscriptions()

controller/nucleus/deviceWatcher.go

@@ -42,15 +42,17 @@ func NewDeviceWatcher(pndStore networkdomain.PndStore) *DeviceWatcher {
 	}
 }
 
-// SubToDevices subscribes to every available device in each network domain with fixed gNMI subscription options (streaming in sample mode each second).
+// SubToDevices subscribes to every available device in each network domain according to provided SubscribeOptions.
 // Paths should be provided in the following format [][]string{{"system", "config", "hostname"}}
-func (d *DeviceWatcher) SubToDevices(paths [][]string) {
-	// TODO: think about passing opts as parameter for more configurability
-	opts := &gnmi.SubscribeOptions{
-		Mode:           gNMISubscribeMode,
-		StreamMode:     gNMIStreamMode,
-		Paths:          paths,
-		SampleInterval: subscribeSampleInterval,
+// SubscribeOptions can be nil. Use nil for a fixed, pre-defined set of gNMI subscription options (streaming in sample mode each second).
+func (d *DeviceWatcher) SubToDevices(paths [][]string, opts *gnmi.SubscribeOptions) {
+	if opts == nil {
+		opts = &gnmi.SubscribeOptions{
+			Mode:           gNMISubscribeMode,
+			StreamMode:     gNMIStreamMode,
+			Paths:          paths,
+			SampleInterval: subscribeSampleInterval,
+		}
 	}
 
 	pnds, err := d.pndStore.GetAll()