feat: uptime monitor

src/app.js

@@ -52,11 +52,13 @@ const mongo = mongoose.createConnection(String(process.env.MONGO_URL), {
 
 // Fork processes
 const hackernewsFork = fork(pathTo(import.meta.url, "./hackernews.js"), { detached: true });
+const uptimeFork = fork(pathTo(import.meta.url, "./uptime.js", { detached: true }));
 
 async function terminate(caller) {
   const t = Date.now();
   bot.stop(caller);
   hackernewsFork.kill();
+  uptimeFork.kill();
   await mongo.close();
   await Sentry.flush();
   terminal.info(`${caller}: ${Date.now() - t}ms`);

src/uptime.js

@@ -0,0 +1,51 @@
+import dotenv from "dotenv";
+import got from "got";
+import * as Sentry from "@sentry/node";
+import { pathTo } from "#utils/path.js";
+
+dotenv.config({ path: pathTo(import.meta.url, "../.env") });
+
+const UPTIME_MONITOR_URL = process.env.UPTIME_MONITOR_URL;
+
+function sleep(ms) {
+  return new Promise((resolve) => setTimeout(resolve, ms));
+}
+
+async function run(url) {
+  const searchParams = new URLSearchParams();
+  searchParams.set("msg", "OK");
+  searchParams.set("ping", "0");
+  searchParams.set("status", "up");
+
+  await got.post(url + "?" + searchParams.toString());
+}
+
+for (;;) {
+  // Don't start the uptime service if the monitor url is empty.
+  if (!UPTIME_MONITOR_URL) {
+    break;
+  }
+
+  let done = false;
+
+  // eslint-disable-next-line no-await-in-loop
+  await run(UPTIME_MONITOR_URL)
+    .catch((error) => {
+      Sentry.captureException(error);
+    })
+    .finally(() => {
+      done = true;
+    });
+
+  while (!done) {
+    // wait
+    await sleep(1000);
+  }
+
+  // How long do we need to sleep
+  const now = new Date();
+  const nextTime = new Date(now.getUTCFullYear(), now.getUTCMonth(), now.getUTCDate(), now.getUTCHours(), now.getUTCMinutes() + 1, now.getUTCSeconds(), 0);
+
+  // eslint-disable-next-line no-await-in-loop
+  await sleep(nextTime.getTime() - now.getTime());
+}