align depth to color received over ros topics

[alonsnir]

I'm trying to convert https://github.com/IntelRealSense/librealsense/blob/master/wrappers/python/examples/align-depth2color.py, so it will receive depth and color messages coming from the realsense2_camera_node and not from rs.pipeline().
I do not find a way for how to align depth to color. Here is a snippet of the subs
self.color_sub = self.create_subscription(Image, '/color/image_raw', self.color_callback, 10) self.depth_sub = self.create_subscription(Image, '/depth/image_rect_raw', self.depth_callback, 10)
Any idea for how to align?
(please note aligned_depth_to_color topic is not available.)
Thanks