ROS2 Image subscriber

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Hello i'm pretty new to ROS2, i would like to make a simple Image subscriber of a ROS2 topic which come from a camera (which is on a drone) in a Gazebo simulation.

I'm using ROS2 foxy and Gazebo11.

First i launch the Gazebo simulator with : gzserver --verbose -s libgazebo_ros_factory.so in a first terminal. Then i spawn a model of a drone with : ros2 run gazebo_ros spawn_entity.py -entity TITI -x 0 -y 0 -z 0.5 -file ~/src_sitl_gazebo/sitl_gazebo/models/typhoon_h480/typhoon_h480.sdf I have modify the .sdf file in order to make it communicate with ROS2 here is the modification

<sensor name="camera" type="camera">
    <pose>0.0 0 -0.162 0 0 0</pose>
    <camera>
      <horizontal_fov>2.0</horizontal_fov>
      <image>
        <format>R8G8B8</format>
        <width>640</width>
        <height>360</height>
      </image>
      <clip>
        <near>0.05</near>
        <far>15000</far>
      </clip>
    </camera>
    <always_on>1</always_on>
    <update_rate>30</update_rate>
    <visualize>true</visualize>
    <plugin name="camera_controller" filename="libgazebo_ros_camera.so">
        <alwaysOn>true</alwaysOn>
        <updateRate>0.0</updateRate>
        <cameraName>camera</cameraName>
        <imageTopicName>image_raw</imageTopicName>
        <cameraInfoTopicName>camera_info</cameraInfoTopicName>
        <frameName>camera_link</frameName>
        <hackBaseline>0.07</hackBaseline>
        <distortionK1>0.0</distortionK1>
        <distortionK2>0.0</distortionK2>
        <distortionK3>0.0</distortionK3>
        <distortionT1>0.0</distortionT1>
        <distortionT2>0.0</distortionT2>
    </plugin>
  </sensor>

I tried to use the ROS2 migration syntax that I found here https://github.com/ros-simulation/gaz... but it gave me some errors.

After that I use :

ros2 topic list

and it gave me this output :

/camera/camera_info
/camera/image_raw
/clock
/parameter_events
/rosout

So I guess the Image Publisher is created but maybe I'm wrong there. Then I wrote a script which is a simple subscriber :

import rclpy
from rclpy.node import Node
from sensor_msgs.msg import Image

class MinimalSubscriber(Node):

    def __init__(self):
        super().__init__('minimal_subscriber')
        self.subscription = self.create_subscription(
            Image,
            '/camera/image_raw',
            self.listener_callback,
            10)
        self.subscription  # prevent unused variable warning

    def listener_callback(self):
        print("In callback")

    def main(args=None):
        rclpy.init(args=args)
        minimal_subscriber = MinimalSubscriber()
        rclpy.spin(minimal_subscriber)
       # Destroy the node explicitly
       # (optional - otherwise it will be done automatically
       # when the garbage collector destroys the node object)
       minimal_subscriber.destroy_node()
       rclpy.shutdown()

if __name__ == '__main__':
    main()

So in the callback I just print a message to see if the callback is working but i don't receive any message in the terminal.

Thank you in advance for helping me feel free to tell me if you need additional information my post is already long i don't want to overload it.