Commit d9fdbea1 authored by vertighel's avatar vertighel
Browse files

Fix uvicorn ws-backend fallback: only trigger on Config.load() failure 



The previous fallback caught any exception from the whole server.run()
call, including ones raised late during Ctrl-C shutdown (the same
websocket close-race, this time from inside uvicorn's own teardown code).
That misread a shutdown-time error as "backend unavailable" and silently
restarted the entire server on the other ws implementation — re-running
every device's startup — right when the operator was trying to stop it.

Now the ws implementation is resolved via Config.load() (which only
imports/resolves protocol classes, no socket bound, no before_serving
hooks touched) before Server(config).run() is ever called. Only a
Config.load() failure triggers the next backend in the list; anything
after that point behaves as before (KeyboardInterrupt handled, anything
else propagates).

Also includes minor UI tweaks (control.html/init.html widget ordering
and defaults).

Co-Authored-By: default avatarClaude Sonnet 5 <noreply@anthropic.com>
parent f89b4c0b

noctua/app.py

+28 −14
Original line number Diff line number Diff line
@@ -54,15 +54,6 @@ class _WebSocketCloseRaceMiddleware: 
app = _WebSocketCloseRaceMiddleware(app)





def _serve(ws):

    """Run uvicorn with the given websocket implementation until Ctrl-C."""



    try:

        uvicorn.run(app, host="0.0.0.0", port=5533, ws=ws)

    except KeyboardInterrupt as e:

        print(f"Shutting down: {e}")





def run():

    """

    Server run using uvicorn.
@@ -76,6 +67,18 @@ def run(): 
    cleanly (e.g. a page reload) can wedge the connection into an

    unrecoverable state instead of raising — see

    https://github.com/Kludex/uvicorn/issues/997.



    The fallback decision is made by calling Config.load() ourselves —

    which is where the ws implementation actually gets imported — before

    the server ever starts serving. That's deliberate: Config.load() only

    resolves protocol classes/settings, it doesn't bind a socket or touch

    the app's before_serving hooks, so a failure there can only mean "this

    backend isn't usable". Catching exceptions from server.run() instead

    would also catch anything raised late during Ctrl-C shutdown (e.g.

    that same close-race, from inside uvicorn's own teardown) and

    misread it as "backend unavailable" — restarting the whole server,

    and every device's startup with it, in the middle of shutting down.

    That's exactly what the previous version of this function did.

    """



    # Only the long-lived noctua-app process should survive an
@@ -84,11 +87,22 @@ def run(): 
    # noctua-guider never call this, so they keep failing loudly.

    check.set_recoverable(True)



    for ws in ("websockets-sansio", "websockets"):

        config = uvicorn.Config(app, host="0.0.0.0", port=5533, ws=ws)

        try:

        _serve(ws="websockets-sansio")

            config.load()

        except Exception as e:

        log.warning(f"uvicorn ws='websockets-sansio' unavailable ({e}), falling back to 'websockets'")

        _serve(ws="websockets")

            log.warning(f"uvicorn ws={ws!r} unavailable ({e}), trying next")

            continue



        try:

            uvicorn.Server(config).run()

        except KeyboardInterrupt as e:

            print(f"Shutting down: {e}")

        return



    raise RuntimeError(

        "No usable uvicorn websocket implementation (tried websockets-sansio, websockets)")





if __name__ == "__main__":

noctua/web/pages/control.html

+2 −2
Original line number Diff line number Diff line
@@ -78,8 +78,8 @@ 
      {{ w.widget_standard({

         "label": "Offsets",

         "inputs": [

         {"label": "Zd", "value": -300},

            {"label": "Az", "value": -300}

         {"label": "Zd", "value": 0},

            {"label": "Az", "value": 0}

            ],

             "unit": "″",

             "buttons": [{"label": "Set", "endpoint": "/telescope/coordinates/offset", "method": "PUT"}],

noctua/web/pages/init.html

+28 −28
Original line number Diff line number Diff line
@@ -191,16 +191,6 @@ 
                ],

            }) }}



            {{ w.widget_standard({

                "label": "Cooling",

                "info": "scicam1-cooler",

                "map": "bool_yesno",

                "buttons": [

                    {"label": "On",  "endpoint": "/scicam1/cooler", "val": true,  "method": "PUT"},

                    {"label": "Off", "endpoint": "/scicam1/cooler", "val": false, "method": "PUT"}

                ],

            }) }}



            {{ w.widget_standard({

                "label": "Temp_1",

                "inputs": [{"value": -10}],
@@ -212,6 +202,16 @@ 
                    {"label": "T",   "status": "scicam1-settings-temperature", "transform": "round_1"}

                ]

            }) }}



            {{ w.widget_standard({

                "label": "Cooling",

                "info": "scicam1-cooler",

                "map": "bool_yesno",

                "buttons": [

                    {"label": "On",  "endpoint": "/scicam1/cooler", "val": true,  "method": "PUT"},

                    {"label": "Off", "endpoint": "/scicam1/cooler", "val": false, "method": "PUT"}

                ],

            }) }}

        </section>



        <section>
@@ -227,16 +227,6 @@ 
                ],

            }) }}



            {{ w.widget_standard({

                "label": "Cooling",

                "info": "scicam2-cooler",

                "map": "bool_yesno",

                "buttons": [

                    {"label": "On",  "endpoint": "/scicam2/cooler", "val": true,  "method": "PUT"},

                    {"label": "Off", "endpoint": "/scicam2/cooler", "val": false, "method": "PUT"}

                ],

            }) }}



            {{ w.widget_standard({

                "label": "Temp_2",

                "inputs": [{"value": -10}],
@@ -248,21 +238,21 @@ 
                    {"label": "T",   "status": "scicam2-settings-temperature", "transform":"round_1"}

                ]

            }) }}

        </section>





        <section>

            <h4 class="mt-2 mb-2">Camera - Échelle</h4>



            {{ w.widget_standard({

                "label": "Cooling",

                "info": "scicam3-cooler",

                "info": "scicam2-cooler",

                "map": "bool_yesno",

                "buttons": [

                    {"label": "On",  "endpoint": "/scicam3/cooler", "val": true,  "method": "PUT"},

                    {"label": "Off", "endpoint": "/scicam3/cooler", "val": false, "method": "PUT"}

                    {"label": "On",  "endpoint": "/scicam2/cooler", "val": true,  "method": "PUT"},

                    {"label": "Off", "endpoint": "/scicam2/cooler", "val": false, "method": "PUT"}

                ],

            }) }}

        </section>





        <section>

            <h4 class="mt-2 mb-2">Camera - Échelle</h4>



            {{ w.widget_standard({

                "label": "Temp_3",
@@ -275,6 +265,16 @@ 
                    {"label": "T",   "status": "scicam3-settings-temperature", "transform": "round_1"}

                ]

            }) }}



            {{ w.widget_standard({

                "label": "Cooling",

                "info": "scicam3-cooler",

                "map": "bool_yesno",

                "buttons": [

                    {"label": "On",  "endpoint": "/scicam3/cooler", "val": true,  "method": "PUT"},

                    {"label": "Off", "endpoint": "/scicam3/cooler", "val": false, "method": "PUT"}

                ],

            }) }}

        </section>

        

    </article>