Sentry tunneling is broken in their example

packages/website/src/routes/sntry/_server.ts

@@ -0,0 +1,36 @@
+
+import { SENTRY_HOST, SENTRY_TUNNEL_ALLOWED_IDS } from '$lib/config';
+import { json, type RequestHandler } from '@sveltejs/kit';
+
+export const POST: RequestHandler = async ({ request }) => {
+    try {
+        const envelopeBytes = await request.arrayBuffer();
+        const envelope = new TextDecoder().decode(envelopeBytes);
+        const piece = envelope.split("\n")[0];
+        const header = JSON.parse(piece);
+        // Sometime the DSN header is not set
+        
+        const dsn = new URL(header["dsn"]);
+        const project_id = dsn.pathname?.replace("/", "");
+
+        if (dsn.hostname !== SENTRY_HOST) {
+            throw new Error(`Invalid sentry hostname: ${dsn.hostname}`);
+        }
+
+        if (!project_id || !SENTRY_TUNNEL_ALLOWED_IDS.includes(project_id)) {
+            throw new Error(`Invalid sentry project id: ${project_id}`);
+        }
+
+        const upstream_sentry_url = `https://${SENTRY_HOST}/api/${project_id}/envelope/`;
+
+        await fetch(upstream_sentry_url, {
+            method: "POST",
+            body: envelopeBytes,
+        });
+
+        return json({}, { status: 200 });
+    } catch (e) {
+        console.error("error tunneling to sentry", e);
+        return json({ error: "error tunneling to sentry" }, { status: 500 });
+    }
+};