Multiple flet apps in a nginx proxy_pass subfolder structure - is that at all possible?

[rkleivel]

/

So - I made my awesome dashboard with flet and published it in a docker container called dash. App is started with:
ft.app(name="", port=8850, target=main, view=ft.WEB_BROWSER)

My nginx reverse proxy (in another docker container) is configured like described in the Self Hosting Guide (only adapted proxy_pass to my environment), and calling https://app.mydomain.com/ works like charm. The dashboard works as expected. Nginx config looks like this:

    location / {
      proxy_pass http://dash:8850/;
      proxy_http_version 1.1;
      proxy_set_header   Upgrade $http_upgrade;
      proxy_set_header   Connection keep-alive;
      proxy_set_header   Host $host;
      proxy_cache_bypass $http_upgrade;
      proxy_set_header   X-Forwarded-For $proxy_add_x_forwarded_for;
      proxy_set_header   X-Forwarded-Proto $scheme;
    }


    location /ws {
      proxy_pass http://dash:8850/ws;
      proxy_http_version 1.1;
      proxy_set_header   Upgrade $http_upgrade;
      proxy_set_header   Connection "upgrade";
      proxy_set_header   Host $host;
      proxy_cache_bypass $http_upgrade;
      proxy_set_header   X-Forwarded-For $proxy_add_x_forwarded_for;
      proxy_set_header   X-Forwarded-Proto $scheme;
    }

/dash

Next step is that I don't really want my dashboard under in the root folder / as I plan to have multiple flet dashboards in /dash, /dash2 ..., and maybe a toolbox in plain html in the root folder / with links to the dashboards

To move my first dashboard from / to /dash I found that the nginx config needs to look like this to work (shortened to show changes or important areas only):

    # https://serverfault.com/questions/1101045/nginx-serve-application-under-sub-path
    if ($http_referer ~ ^https?://app.mydomain.com/dash) {
        rewrite ^ /dash:8850$uri;
    }

    location /dash {
      proxy_pass http://dash:8850/;
      .
      .
    }

    location /ws {
      proxy_pass http://dash:8850/ws;
      .
      .
    }

With this config my dashboard works fine on https://app.mydomain.com/dash. The changes I made are 1) adding the rewrite block and 2) change the app location from / to /dash SO FAR SO GOOD

BUT WAIT - why didn't I change the location for websocket from /ws to /dash/ws as you would expect just following the pattern? Because that did not work. And I did try adding another rewrite block like this:

 #   if ($http_referer ~ ^https?://app2.dev.bergenengines.com/dash/ws) {
 #       rewrite ^ /dash:8850/ws$uri;
 #   }

/dash and /dash2

I am by no means any expert on nginx nor websocket. But testing confirms that I cannot add the second dashboard by just adding a second rewrite and location like this

    if ($http_referer ~ ^https?://app.mydomain.com/dash2) {
        rewrite ^ /dash2:8850$uri;
    }

    location /dash2 {
      proxy_pass http://dash2:8850/;
      .
      .
    }

because I would also need to route websocket to the 2 different containers dash and dash2, and that is not possible as long as the websocket locations would be /ws for both of them.

So to the question(s):

• Can someone help me achieve my goal?
• Maybe it is possible to customize the websocket endpoints paths in flet? (I found this commit that I think suggests it should be possible)
• Maybe some other nginx config could manage to distinguish the traffic to each of the websockets?
• Any hint appreciated :)

[FeodorFitsner]

This is exactly the feature I'm working on right now: hosting multiple Flet web apps with production-grade durability!
In this scenario FastAPI is replacing built-in Fletd web server and the entire setup is run by gunicorn/uvicorn. WebSocket connections are managed by Starlette/FastAPI and Flet program "lives" inside it. One of the requirements to a Flet program though - it must be async in order to work with FastAPI.

I'm doing final touches in that PR and hopefully merge it tomorrow, so we all will have a chance to give it a try.
To get prepared start adjusting your app(s) to be async: https://flet.dev/docs/guides/python/async-apps

It's exciting to see Flet handling dozens of sessions/connections while gunicorn has only one thread running! :)

[rkleivel]

Ah - that's great news 😊👍 Looking fwd to that feature!