add support for deploying on cloudflare pages

.gitignore

@@ -3,7 +3,8 @@ dist
 packages/website/tools/.fusebox
 packages/backend/data
 packages/backend/target
-packages/exporter/data
+packages/exporter/data/*
+!packages/exporter/data/output
 packages/exporter/target
 packages/lua-runtime/tools/emsdk
 packages/lua-runtime/tools/cache

functions/corsproxy.js

@@ -0,0 +1,26 @@
+export async function onRequest({ request }) {
+    const url = new URL(request.url)
+    let apiUrl = url.searchParams.get('url')
+
+    if (apiUrl == null) {
+        return new Response()
+    }
+
+    // Rewrite request to point to API url. This also makes the request mutable
+    // so we can add the correct Origin header to make the API server think
+    // that this request isn't cross-site.
+    const proxyRequest = new Request(apiUrl, request)
+    proxyRequest.headers.set('Origin', new URL(apiUrl).origin)
+    let response = await fetch(proxyRequest, { redirect: 'follow' })
+
+    // Recreate the response so we can modify the headers
+    response = new Response(response.body, response)
+
+    // Set CORS headers
+    response.headers.set('Access-Control-Allow-Origin', url.origin)
+
+    // Append to/Add Vary header so browser will cache response correctly
+    response.headers.append('Vary', 'Origin')
+
+    return response
+}