ops(relay): bridge production traffic to Fly

packages/relay/src/cutover-proxy.ts

@@ -0,0 +1,17 @@
+interface CutoverProxy {
+  fetch(request: Request): Promise<Response>;
+}
+
+export function createCutoverProxy(origin: string): CutoverProxy {
+  const originUrl = new URL(origin);
+
+  return {
+    async fetch(request: Request): Promise<Response> {
+      const upstreamUrl = new URL(request.url);
+      upstreamUrl.protocol = originUrl.protocol;
+      upstreamUrl.host = originUrl.host;
+
+      return fetch(new Request(upstreamUrl, request));
+    },
+  };
+}