Drydock does not load on mobile anymore

[begunfx]

Drydock version

1.5.1-rc.4

What happened?

I just get a white screen. Running on an Android - Pixel 10 Pro, latest version.

What did you expect?

see above

Steps to reproduce

see above

Relevant configuration

Logs

Installation method

Docker Compose

Docker version

24.0.1

OS / Architecture

Synology DSM 7

[scttbnsn]

Thanks for the report, and sorry for the hassle. I dug into this pretty hard on my end (read through everything that changed in the UI for rc.4) and I can't find a code path that would blank the screen on mobile but not desktop, and our live demo loads fine on a Pixel-sized viewport with no console errors. So the trail points at something about your setup, and I need a bit more to pin it down.

If you get a sec, could you grab a few of these:

1. Is it a literally white screen, or dark/near-black? That tells me whether the app died before painting anything vs. loaded partway.
2. How are you hitting it on the phone? Straight to http://<synology-ip>:<port>, or through a reverse proxy / the DSM app portal / QuickConnect / a domain name? And is it http or https?
3. Does desktop work on that exact same URL? And does the phone work if you hit the raw http://<ip>:<port> directly instead of however you normally reach it?
4. What were you on before rc.4 that worked, rc.3 or the 1.5.0 stable?
5. The gold one if you can manage it: plug the phone into a computer, open chrome://inspect in desktop Chrome, and grab the Console and Network tabs for the phone's tab while it's showing the white screen. Even a screenshot of the console errors would crack this wide open.
6. Are you opening it as a normal browser tab, or did you install it to the home screen as an app?

My working theory is it's about how the app's being served to the phone (a proxy or a plain-http origin) rather than the app code itself, but the console log from your device would tell us for sure. Appreciate you sticking with it.

[begunfx]

Quick high-level updates: It's literally a white screen. I'm hitting drydock via reverse proxy. I've seen this with other apps and believe it's reverse proxy related. I do not know version the problem started but I'm pretty sure it was working prior to 1.5.1. I was on the last rc candidate for 1.5.0 prior. Drydock does work on desktop via the same reverse proxy.

[scttbnsn]

Thanks, that's really helpful and it lines up with what I found digging through the code. Nothing in drydock's actual code or its security headers changed between 1.5.0 and 1.5.1 that would blank mobile-only, so this is almost certainly your phone (or the proxy in front of it) serving a cached copy of the old build.

Here's the mechanism: every release, the app's JS/CSS files get new hashed filenames and the old ones are deleted. drydock already tells browsers not to cache the HTML page (Cache-Control: no-store), but plenty of reverse proxies cache it anyway, so after an upgrade the proxy hands your phone the old HTML, which points at JS bundles that no longer exist. The browser gets nothing to run and you get a white screen. Your desktop most likely pulled the fresh copy, which is why it's fine through the same proxy.

Two things that'd help:

1. Quick one to confirm it: on the phone, clear drydock's site data / cache (or if you added it to your home screen, remove and re-add it), then reload. If you can purge your reverse proxy's cache too, do that. Does it come back?
2. If you get a sec on chrome://inspect → Network while it's white, I'd bet you see a red 404 (or a JS file coming back as text/html) on a /assets/*.js request. That nails it. And which reverse proxy are you running (Nginx Proxy Manager / SWAG / Traefik / Caddy / the DSM built-in)? A couple of them cache HTML by default and that's the usual culprit.

On our end I'm going to (a) add a reverse-proxy page to the docs with the exact cache settings that avoid this, and (b) tighten how drydock answers a request for an asset that no longer exists so a stale page fails cleanly instead of white-screening. Appreciate you sticking with it.

[begunfx]

I tried it again on my phone and now it's working. Like you said it was probably a caching thing and I guess it finally updated. I appreciate you adding a reverse-proxy page to the docs. Otherwise I think you can close this. Thanks!

[scttbnsn]

Closing this out since you confirmed it's working again. Final read: a caching reverse proxy served a stale index.html that pointed at deleted hashed asset files after the upgrade, so the phone got a blank page while a fresh desktop load worked. Not a drydock code bug, but two hardenings ship in v1.6 anyway: the server now returns a 404 for missing hashed assets instead of HTML (so stale pages fail fast instead of white-screening), and the docs get a section on reverse proxy caching. Thanks for sticking with the diagnostics.