can't subscribe or publish messages without bebop_autonomy driver running

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Hey guys, I am new to ROS and I encountered problems in subscribing and publishing messages into topics. I try to subscribe and publishing them to Parrot Bebop2 drone.

I face this problem in different code files I try to execute, one simple example:

#! /usr/bin/python
# Copyright (c) 2015, Rethink Robotics, Inc.
# Using this CvBridge Tutorial for converting
# ROS images to OpenCV2 images

import rospy
from sensor_msgs.msg import Image
from cv_bridge import CvBridge, CvBridgeError
import cv2

bridge = CvBridge()

def image_callback(msg):
  print("Received an image!")
  try:
    cv2_img = bridge.imgmsg_to_cv2(msg, "bgr8")
  except CvBridgeError, e:
    print(e)
  else:
    cv2.imwrite('camera_image.jpeg', cv2_img)

def main():
  rospy.init_node('image_listener')
  image_topic = "/bebop/image_raw"
  rospy.Subscriber(image_topic, Image, image_callback)
  rospy.spin()

 if __name__ == '__main__':
  main()

However, when I execute this code while I run the bebop_autonomy driver nodelet, this code runs fine. I can see in the rqt_graph that when I run the driver nodelet there is a subscription, and otherwise the node "Image_listener" stands alone. So I guess the problem is related to the connection to the bebop2.

To mention, I use ROS Kinetic and I run Ubuntu 16.04 OS.

What am I missing? :(

and thx in advance, Oren