500 Server error when deployed to Cloudflare

[MattHeslington]

Good morning,

I have a SvelteKit implementation of Lucia (v2.5) using PlanetScale and deployed to Cloudflare pages. It's just the simple username and password example from the documentation. Everything works well in development, but when deployed I get a 500 server error when a user tries to sign-up, and with it being in a production environment I'm finding it difficult to debug what's happening. The same build deploys correctly to Vercel

I'm just wondering if there are any known issues about this setup I should be aware of which may be causing this problem?

Cheers,
Matt

[pilcrowonpaper]

If you’re using the free plan, there isn’t enough compute resource for password hashing

[MattHeslington]

I will move to the paid plan this afternoon - I'll confirm all is good asap

Edit: And fantastic package by the way - I love it!

[MattHeslington]

Update: On the paid plan now but still having the same issue as before. Trying to sign-up causes the following error:

500
Unexpected token '<', "<!DOCTYPE "... is not valid JSON

which is usually caused by a fetch or JSON parse issue

[pilcrowonpaper]

Client side or server side? Unless you're using the OAuth integration, Lucia doesn't fetch(). It's possible that SvelteKit is trying to make a request but Cloudflare/SvelteKit is sending a generic error page or something.

[hynj]

I had similar issues, I am also using planetscale and sveltekit on CF pages. As Pilcrow mentioned it was due to Sveltekit fetching and CF returning a "resource limit exceeded HTML page". I worked out this was the case by using the streaming log's feature and then I could see the errors and my console.log output.

I was already on the default "paid plan" and using the default "bundled" pricing model. It only allowed 50ms of execution. I have found that the function takes a median of around 200-300ms..

CF would let these requests sporadically go through. I moved to the "unbundled" function pricing model and this has sort of fixed the issue, I am now on the new pricing scheme which also sort of works. It still doesn't really work as expected though..

As you can see from the graph, it quite often takes significantly longer to log in and register, around 4-5seconds of function execution. Which still leads to issues logging in and registering. For example this if I put some console.log's into the login flow like this, you can see "await auth.createSession" takes 4 seconds.

This is the resulting log output

I thought this may be a Planetscale related issue and decided to use CF D1, I had similar issues.. Not sure if using a less resource intensive hashing algorithm would partially fix it? Hope this helps

[MattHeslington]

This is excellent information, many thanks

[mateoroldos]

Any update on this issue @MattHeslington?

We are trying to deploy a SvelteKit application with Lucia / Planetscale on Cloudflare Pages and we are facing very similar issues.

[MattHeslington]

Unfortunately, not. I decided to put it to one side while I worked on other things.
I've just tried it again in case it was some legacy CF issue, but the problem still remains. Not a great experience tbh since it's very difficult to debug. Fortunatelty OAuth seems to be working, though I'll confirm this later.