Unable to make UI works in K8s cluster with internal redirections

[AlexGacon]

Hello there,

We would like to use the new web UI on our Martin instance but we don't manage to have it working correctly.

Our Martin instance is hosted on a Kubernetes cluster which uses Traefik for ingress. The main enter point for our setup points to a backend written with FastAPI which also routes requests to other components, including Martin.

A request to the root of the martin server reaches martin but the returned HTML contains links to assets which are relative to the root of martin but not to the URL exposed to the end users.

The URL looks like https://mywonderfuldomain/api/martin/, which is intercepted by our FastAPI backend which then do another request to martin inside our cluster.

I hope this is clear enough.

[AlexGacon]

Perhaps using the config https://vite.dev/config/server-options.html#server-origin is a possibility?

[CommanderStorm]

That won't work. The link you posted is for the bite dev server.

On the server side, we don't execute JavaScript. This is done at build time.
We assume that from some path forward the rest of the path belongs to us and routing is not changed here.

I don't quite follow what your exact redirection scheme is and how it breaks.
We allow subpaths if this is what you are asking => https://nav.tum.de/tiles/

Could you share more details on what your scheme is?

[AlexGacon]

Thank you for your quick reply.

My scheme is the following:

• Users connects to https://mywonderfuldomain/ which is our front.
• All the requests from the front to our main backend are done on https://mywonderfuldomain/api (FastAPI backend), to control and limit what we expose.
• Requests for Martin are done on https://mywonderfuldomain/api/martin, with a redirection done from the FastAPI backend to the server hosting Martin.

Is it clearer?

As a workaround, is it possible to deploy a Martin docker image just to deploy the web ui and to connect to my real Martin instance?

[AlexGacon]

On https://aquarepere.banquedesterritoires.fr/territoire/64df477b-cd4e-45b0-b57d-408484726748/Ain/decouvrir, you can find an example with calls to Martin Tile Server.

[nyurik]

Martin already uses URL rewrites provided by proxies -- this way generated tilejson uses the correct externally visible URL rather than the internal one. Perhaps it is not implemented for the UI?

See also

• configuring NGINX -- https://maplibre.org/martin/run-with-nginx.html#rewriting-urls

• martin/martin/tests/pg_server_test.rs

  Lines 883 to 893 in 9395110

  	let req = TestRequest::get()
  	.uri("/function_zxy_query_jsonb?token=martin")
  	.insert_header(("X-Forwarded-Proto", "https"))
  	.insert_header(("X-Forwarded-Host", "example.org:7654"))
  	.insert_header(("X-Rewrite-URL", "/proxy/function_zxy_query_jsonb"))
  	.to_request();
  	let result: TileJSON = call_and_read_body_json(&app, req).await;
  	assert_eq!(
  	result.tiles,
  	&["https://example.org:7654/proxy/function_zxy_query_jsonb/{z}/{x}/{y}?token=martin"]
  	);

[AlexGacon]

Indeed it is not implemented I think. https://vite.dev/guide/build.html#public-base-path could be a solution maybe.

[nyurik]

Could you clarify - does Martin generate incorrect URLs as part of the served javascript or other data sent from the server, or does Javascript incorrectly generates link URLs?

[CommanderStorm]

Your solution does not work as we don't execute JavaScript on the server.

Given that all URLs that the frontend expects are relative to where we are served instead of absolute, this should not be nessesary though.

If you just serve from your /martin prefix and your fastapi step removes the prefix, that works.
I don't quite get where the issue lies.