run checks periodically, auto restart services

src/index.ts

@@ -2,10 +2,11 @@ import Revolt from 'revolt.js';
 import Discord from 'discord.js';
 import Express from 'express';
 import { config } from 'dotenv';
+import { exec } from 'child_process';
 
 config();
 
-const { DISCORD_TOKEN, REVOLT_TOKEN, DISCORD_CHANNEL, REVOLT_CHANNEL, PORT } = process.env;
+const { DISCORD_TOKEN, REVOLT_TOKEN, DISCORD_CHANNEL, REVOLT_CHANNEL, PORT, RESTART_COMMAND_BOT, RESTART_COMMAND_BRIDGE } = process.env;
 
 if (!DISCORD_TOKEN) throw '$DISCORD_TOKEN not set';
 if (!REVOLT_TOKEN) throw '$REVOLT_TOKEN not set';
@@ -20,6 +21,9 @@ const clients = {
     revolt: new Revolt.Client({ autoReconnect: true, pongTimeout: 30, onPongTimeout: 'RECONNECT' }),
 }
 
+let currentValue: Awaited<ReturnType<typeof periodicCheck>>|null = null;
+let restarting = { bot: false, bridge: false };
+
 const app = Express();
 app.listen(PORT, () => console.log('Listening on :' + PORT));
 
@@ -30,15 +34,32 @@ clients.discord.on('ready', () => console.log('Discord ready'));
 clients.revolt.on('ready', () => console.log('Revolt ready'));
 
 app.get('/healthcheck', async (req: Express.Request, res: Express.Response) => {
+    console.log('Health check request received');
+
+    if (!currentValue) {
+        console.log('No health check result stored yet, running checks');
+        await periodicCheck();
+    }
+
+    res.status(currentValue!.status).send(currentValue);
+});
+
+const periodicCheck = async () => {
+    console.log('Running periodic check');
+    const now = new Date().toISOString();
     const [ botStatus, bridgeStatusDiscord, bridgeStatusRevolt ] = await Promise.all([
         retry(checkBot, 3),
         retry(checkBridgeDiscord, 3),
         retry(checkBridgeRevolt, 3),
     ]);
 
-    let statusCode = (botStatus && bridgeStatusDiscord && bridgeStatusRevolt) ? 200 : 503;
-    let response = {
+    if (botStatus) restarting.bot = false;
+    if (bridgeStatusDiscord && bridgeStatusRevolt) restarting.bridge = false;
+
+    const statusCode = (botStatus && bridgeStatusDiscord && bridgeStatusRevolt) ? 200 : 503;
+    const response = {
         status: statusCode,
+        checkedOn: now,
         ready: {
             discord: !!clients.discord.readyAt,
             revolt: !!clients.revolt.websocket.ready,
@@ -50,8 +71,43 @@ app.get('/healthcheck', async (req: Express.Request, res: Express.Response) => {
         },
     };
 
-    res.status(statusCode).send(response);
-});
+    currentValue = response;
+    runRestarts(response).catch(e => console.log(e)); // Explicitly do not await this
+    return response;
+}
+
+const runRestarts = async (status: Awaited<ReturnType<typeof periodicCheck>>) => {
+    if (!status.watchdog.bot && !restarting.bot && RESTART_COMMAND_BOT) {
+        console.log('Restarting bot');
+        try {
+            restarting.bot = true;
+            const result = exec(RESTART_COMMAND_BOT!);
+            result.stdout?.on('data', data => console.log(data));
+            result.stderr?.on('data', data => console.log(data));
+        } catch(e) {
+            console.log(e);
+        }
+    }
+
+    if ((!status.watchdog.bridgeDiscord || !status.watchdog.bridgeRevolt) && !restarting.bridge && RESTART_COMMAND_BRIDGE) {
+        console.log('Restarting bridge');
+        try {
+            restarting.bridge = true;
+            const result = exec(RESTART_COMMAND_BRIDGE!);
+            result.stdout?.on('data', data => console.log(data));
+            result.stderr?.on('data', data => console.log(data));
+        } catch(e) {
+            console.log(e);
+        }
+    }
+}
+
+setInterval(async () => {
+    if (clients.discord.readyAt && clients.revolt.user) {
+        await periodicCheck();
+    }
+    else console.log('Cannot run periodic check as clients aren\'t ready yet');
+}, 30000);
 
 const checkBot = (): Promise<boolean> => new Promise(async (resolve, _reject) => {
     const id = Math.round(Math.random() * 1000000);