`paths.base` production build routing issue

[inzanez]

Describe the problem

Hi all

I serve a Svelte application through a reverse proxy under a sub-path like http://my-site.com/sub/path. When forwarding the requests, the reverse proxy rewrites the path so that /sub/path gets removed, resulting in requets to the Svelte deployment as if it were hosted at the root.
To make this work, I set paths.base to /sub/path. Using the node adapter, it prepended that paths.base to every static asset URL so that it was correctly fetched.

After upgrading to the most recent version of @sveltejs/kit and @adapter/node things do not seem to work anymore. When setting the paths.base variable, it seems that the resulting node build expects me to hit the server with the routes ${paths.base}/actual-route. Which is not really how it used to work,...

Describe the proposed solution

Fix routing based on paths.base...

Alternatives considered

No response

Importance

nice to have

Additional Information

No response

[dummdidumm]

• from what version did you upgrade?
• please provide a reproducible

[inzanez]

I did upgrade from:

"@sveltejs/adapter-node": "^1.0.0-next.46",
"@sveltejs/kit": "^1.0.0-next.166",
"svelte": "^3.46.4",
...

to

"@sveltejs/adapter-node": "^1.0.0-next.104",
"@sveltejs/kit": "^1.0.0-next.577",
"svelte": "^3.46.4",

I do not see how I could deliver a reproducible as it all depends on the proxy being in place and rewriting URLs,...?

[dummdidumm]

Wow that's ... a big jump 😅 Could you check what happens if you're pinning the version to 1.0.0-next.578 (the last one that uses Vite 3; so you need to pin that to 3 as well)? Want to make sure it's not a result of that.

Re "how": You could provide a GitHub repository with all the necessary things wired up. For the proxy, a thorough explanation how to set it up (maybe there's a way to use a simpler proxy that can also be included in the GitHub repo and setup correctly).

[inzanez]

@dummdidumm Yes, it is quite a jump :-) Well, I will try and put something together, that might take some time though. I have just tried a fresh project and played around with the static adapter,...and I think I have seen some weird routing behavior as well (at least from what I am used to).

I will be back with a repo and more detailed information,...

[inzanez]

@dummdidumm
https://github.com/inzanez/svelte-routing

There are two branches, old-version and new-version. You might register the difference between the two.
Have the final application using only relative paths so that it will fetch the right assets and work wherever it is hosted (path-wise,...so it might be 10 levels deep in a folder structure on an nginx server but it would still run).

All in all, it seems that the behavior changed from the older version to the newer. With the newer, I would have to turn off the path-rewriting in the proxy.

[dummdidumm]

maybe you are seing the changed behavior due to this PR #4448 which fixed the longstanding issue #3726 . If so, then that's expected and you need to adjust your path-rewriting.

[inzanez]

@dummdidumm Yes, that seems to be the case :-) Absolutely agree with that.