Embeding: share doc across tornado and bokeh app

Community Support
1

Dear all,

I am working on embeding a bokeh app inside of an already existing tornado app. I saw that it was possible to share the same ioloop, so I have a main that looks like this:

if __name__ == '__main__':
    # First instantiate main tornado infrastructure
    http_server = tornado.httpserver.HTTPServer(TornadoApplication())
    http_server.listen(tornado.options.options.port)
    io_loop = tornado.ioloop.IOLoop.current()

    # Now instantiate bokeh app
    bokeh_server = Server({'/bokeh_app': bokeh_app},
                          io_loop=io_loop,
                          allow_websocket_origin=['localhost:8888'])

    # Launch the whole thing
    io_loop.start()

And somwhere in my tornado handler, I get the generated bokeh script with:
script = server_document('http://localhost:5006/bokeh_app')

The problem is that, I would like to modify (like add points on user post, or add new data upon database update, or any event that might come from tornado).
The only way I found up to now, was to keep a dictionary of existing documents created per each user as a global variable shared both by the tornado handlers and bokeh_app.

As soon as certain event arise within tornado, I fetch the bokeh document with the right key within the dictionary and update it with:

document.add_next_tick_callback(update)

Now the problem that I have no way to share a unique identifier for each user, that would be shared in between tornado (like a cookie) and bokeh like a session id.
My main leads are:

  • Try to read a secure cookie from bokeh app ?
  • Try to force a session_id when including bokeh inside tornado handler with server_session instead of server_document for instance with a session_id that would be equal to the cookie value

What is in you opinion to do something like this ?

Thank you very much for your help

2

I would create a session ID outside of Bokeh, yes. That’s exactly what I’m doing in my app.
More than that, it’s just the current user session ID - throughout the whole app, not just for Bokeh. And I don’t use Bokeh auth as well, if that matters - Bokeh just manages plots and bidirectional communication, everything else is managed by the rest of the app.

1 Like
3

Tank you for your feedback.
As I was checking the documentation: bokeh.embed — Bokeh 3.3.2 Documentation
for
``server_session ( *model=None* , *session_id=None* , *url='default'* , *relative_urls=False* , *resources='default'* , *headers={}* )

I see:

Return a script tag that embeds content from a specific existing session on a Bokeh server.
This function is typically only useful for serving from a a specific session that was previously created using the bokeh.client API.

Do you know of any example about how to create a document explicitly, to get the session_id from there ?

4

Do you know of any example about how to create a document explicitly, to get the session_id from there ?

You would have to re-implement quite a bit a the code that’s already written in Bokeh. That’s why generating your own session ID is a much simpler approach.

1 Like
5

Great ! I ignored it was possible just to provide an arbitrary number to server_session, I’ll try that asap

6

It worked perfectly, thank you very much !!!

7

Don’t provide it just some small number though. Use UUID or something like that if you use nothing but session ID for authentication.