Serve both UI assets and REST API from handler

ui/src/api.ts

@@ -5,7 +5,7 @@ import queryString from "query-string";
 // the static file server.
 // In developement, we assume that the API server is listening on port 8080.
 const BASE_URL =
-  process.env.NODE_ENV === "production" ? "/api" : "http://localhost:8080/api";
+  process.env.NODE_ENV === "production" ? `${window.ROOT_PATH}/api` : `http://localhost:8080${window.ROOT_PATH}/api`;
 
 export interface ListQueuesResponse {
   queues: Queue[];

ui/src/global.d.ts

@@ -0,0 +1,5 @@
+interface Window {
+  // Root URL path for asynqmon app.
+  // ROOT_PATH should not have the tailing slash.
+  ROOT_PATH: string;
+}

ui/src/paths.ts

@@ -1,11 +1,11 @@
 export const paths = {
-  HOME: "/",
-  SETTINGS: "/settings",
-  SERVERS: "/servers",
-  SCHEDULERS: "/schedulers",
-  QUEUE_DETAILS: "/queues/:qname",
-  REDIS: "/redis",
-  TASK_DETAILS: "/queues/:qname/tasks/:taskId",
+  HOME: `${window.ROOT_PATH}/`,
+  SETTINGS: `${window.ROOT_PATH}/settings`,
+  SERVERS: `${window.ROOT_PATH}/servers`,
+  SCHEDULERS: `${window.ROOT_PATH}/schedulers`,
+  QUEUE_DETAILS: `${window.ROOT_PATH}/queues/:qname`,
+  REDIS: `${window.ROOT_PATH}/redis`,
+  TASK_DETAILS: `${window.ROOT_PATH}/queues/:qname/tasks/:taskId`,
 };
 
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