readsb-protobuf
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Mictronics
Sometimes the UI shows no planes
More conversation over at a Docker container that uses this tool.
The main symptom is that the UI loads but there's a script load failure due to the wrong URL being passed to the server. The more I experience it, the more I wonder if it's some kind of weird race condition in the base URL.
I stumbled on the problem again today on a browser that was working fine before. This time was an error attempting to load aircraftCollection.js. I will note that the readsb UI is running behind a reverse proxy that adds a layer to the path, so the UI is at https://hostname/planes. The script at uiBody.ts (line 44) was attempting to load "./script/readsb/backend/aircraftCollection.js" which was, for some reason, resolving to https://hostname/script/readsb/backend/aircraftCollection.js instead of https://hostname/planes/script/readsb/backend/aircraftCollection.js.
While I was experiencing the bug I loaded the page in an incognito window. It worked fine! I went back to the normal browser and it was still broken. I pressed Ctrl-Shift-R, I browsed through the code in the Chrome DevTools, I reloaded a few times, went back and forth ... eventually it magically started working again in the normal browser and I don't know why. Now it's working again. The browser asks for the correct URL for aircraftCollection.js.
Note that my original bug report on the other page was not running behind a reverse proxy.
pretty sure that's a caching issue ... because the location of that js file changed.
I've tried Ctrl-Shift-R and that didn't work. Is there another form of storage in use that isn't cleared by Ctrl-Shift-R?
i think that might be a problem with the container, i don't think it's related to this project.
well this project doesn't have any cache busting but .... can't have everything.
So i'm pretty sure the described issue has to do with lighttpd.
When mod_deflate is enabled, lighttpd will sometimes cause an internal 404 for aircraftCollection.js which leads to an automatic redirect to aircraftCollection.js/ .... this changes all relative paths and causes the issue. Further that redirect is a 301 which seems to persist even a Ctrl - shift -R .... you need to clear all cache for that page to remove it in chrome.
Oooh, that sounds like a very reasonable possibility. I will relay this suggestion to the Docker container team and see if we can track it down there. Thanks!