Update Google Map Server code/instructions

[potto216]

I'm having problems using the Google Map Server example. It is warning me that the keyless option will soon be deprecated and what is worse I cannot get the detected tracks to show up. If the project is still being maintained I would be happy to debug the issue and submit a PR.

[mhostetter]

Help here would be very welcome. A while back I did notice a similar issue. At the time of development, operation worked well without an API key. I think users received N free uses (tile queries, etc) per day. It seems Google is cracking down a bit.

[mhostetter]

Also, full disclosure, this was my first foray into web development of any kind. So, the javascript and Flask webserver surely could be improved. 😆

[potto216]

Thanks for the info, I was planning on forking the repo and creating a branch PR unless you rather I make the changes on master.

[mhostetter]

Yes, that sounds good. I would make the changes on a separate branch.

[mhostetter]

I am testing now with my setup. The Google Maps webpage gives me "For development purposes only" watermarks and a Google Maps JavaScript API warning: NoApiKeys https://developers.google.com/maps/documentation/javascript/error-messages#no-api-keys warning, but I do see the plane tracks.

Can you provide me any more diagnostics (webserver stdout, webpage console, etc) on your setup. I might be able to help you debug why you aren't seeing planes on the webpage.

[potto216]

I was getting

(ads_b_app) user@sdr:~/src/ads_b_app/web$ python ./webserver.py
Waiting for zmq socket to connect.
Exception in thread Thread-1:
Traceback (most recent call last):
  File "/home/user/.pyenv/versions/3.7.4/lib/python3.7/threading.py", line 926, in _bootstrap_inner
    self.run()
  File "/home/user/.pyenv/versions/3.7.4/lib/python3.7/threading.py", line 870, in run
    self._target(*self._args, **self._kwargs)
  File "./webserver.py", line 42, in background_thread
    socket.setsockopt(zmq.SUBSCRIBE, "")
  File "zmq/backend/cython/socket.pyx", line 426, in zmq.backend.cython.socket.Socket.set
TypeError: unicode not allowed, use setsockopt_string

 * Restarting with stat
 * Debugger is active!
Waiting for zmq socket to connect.
Exception in thread Thread-1:
Traceback (most recent call last):
  File "/home/user/.pyenv/versions/3.7.4/lib/python3.7/threading.py", line 926, in _bootstrap_inner
    self.run()
  File "/home/user/.pyenv/versions/3.7.4/lib/python3.7/threading.py", line 870, in run
    self._target(*self._args, **self._kwargs)
  File "/home/user/src/ads_b_app/web/webserver.py", line 42, in background_thread
    socket.setsockopt(zmq.SUBSCRIBE, "")
  File "zmq/backend/cython/socket.pyx", line 426, in zmq.backend.cython.socket.Socket.set
TypeError: unicode not allowed, use setsockopt_string

Which went away when I forced a binary string in
socket.setsockopt(zmq.SUBSCRIBE, b"")
in webserver.py. I'll try it with live data shortly and add a comment with my result.

[mhostetter]

The python webserver needs to run with Python 2.7. I probably should make that more clear in the docs. It's very likely the zmq and flask packages are different for Python 3. It appears your python symlink is referencing Python 3.7.

[potto216]

Oh okay my bad, I'll try it with Python 2.7. That will be an easy issue to close:)

[potto216]

I was able to get the map server code to work without problems when I had properly set my environment to Python 2.7. Therefore this is not an issue an I am closing it.