Fix a lock-up of the stats-getter

For some reason, those promises never settle, so we end up stuck
trying to load users. Provide our own timeout on top of it, so that we
bail if this happens.

src/pushStats/users.js

@@ -5,38 +5,45 @@ const SERVER_PORT = parseInt(/** @type {string} */ (process.env.SERVER_PORT), 10
 
 /**
  * Check whether there's a server nearby
- * @returns {Promise<[string, number]>}
+ * @returns {Promise<[string, number] | undefined>}
  */
 async function checkLocalhostServer() {
   const hosts = [
     'localhost',
     'host.docker.internal',
     '172.17.0.1',
   ];
-  /** @type {Promise<[string, number]>[]} */
+  /** @type {Promise<[string, number] | undefined>[]} */
   const promises = [];
   for (const host of hosts) {
     const p = new Promise((resolve, reject) => {
       const sock = new net.Socket();
-      sock.setTimeout(2500);
+      function kill() {
+        sock.removeAllListeners();
+        sock.end();
+        sock.destroy();
+        sock.unref();
+      }
+      sock.setTimeout(200);
       console.log(`[${host}:${SERVER_PORT}] attempting connection`);
       sock
-        .on('connect', () => {
-          sock.destroy();
+        .once('connect', () => {
+          kill();
           resolve([host, SERVER_PORT]);
         })
-        .on('error', () => {
-          sock.destroy();
-          reject();
+        .once('error', () => {
+          kill();
+          reject(new Error('Error connecting to server'));
         })
-        .on('timeout', () => {
-          sock.destroy();
-          reject();
+        .once('timeout', () => {
+          kill();
+          reject(new Error('Timeout connecting to server'));
         })
         .connect(SERVER_PORT, host);
     });
     promises.push(p);
   }
+  promises.push(new Promise((resolve) => { setTimeout(() => resolve(undefined), 1000); }));
   return Promise.any(promises);
 }
 
@@ -78,6 +85,9 @@ export default async function loadUsers() {
     if (!user.host) {
       try {
         if (user.type === 'private') {
+          if (!localServer) {
+            throw new Error('no local server available, and host unspecified');
+          }
           [user.host, user.port] = localServer;
         } else {
           [user.host, user.port] = getHostInfoFromType(user.type);
@@ -101,5 +111,6 @@ export default async function loadUsers() {
     }
     validUsers.push(user);
   }
+  console.log(`Loaded ${validUsers.length} users (out of ${users.length})`);
   return validUsers;
 }