Combine reallink and label for cameras on linux (#311)

pkg/driver/camera/camera.go

@@ -1 +1,16 @@
+/*
+Package camera provides a video camera driver.
+
+Device Label Generation Rules
+
+On Linux, the device label will be in the format of:
+	/dev/video0;/dev/v4l/by-path/pci-0000:00:00.0-usb-0:0:0.0-video-index0
+If /dev/v4l/by-path/* is not available (for example in a docker container without
+bindings in /dev/v4l/by-path/), it will be:
+	/dev/video0;/dev/video0
+*/
 package camera
+
+// LabelSeparator is used to separate labels for a driver that
+// is found from multiple locations on a host.
+const LabelSeparator = ";"

pkg/driver/camera/camera_linux.go

@@ -96,11 +96,11 @@ func init() {
 			discovered[reallink] = struct{}{}
 			cam := newCamera(device)
 			priority := driver.PriorityNormal
-			if label == prioritizedDevice {
+			if reallink == prioritizedDevice {
 				priority = driver.PriorityHigh
 			}
 			driver.GetManager().Register(cam, driver.Info{
-				Label:      label,
+				Label:      label + LabelSeparator + reallink,
 				DeviceType: driver.Camera,
 				Priority:   priority,
 			})