Add ready endpoint

src/routes/getReady.ts

@@ -0,0 +1,13 @@
+import { Request, Response } from "express";
+import { Server } from "http";
+import { config } from "../config";
+
+export async function getReady(req: Request, res: Response, server: Server): Promise<Response> {
+    const connections = await new Promise((resolve) => server.getConnections((_, count) => resolve(count))) as number;
+
+    if (!connections || connections < config.maxConnections) {
+        return res.sendStatus(200);
+    } else {
+        return res.sendStatus(500);
+    }
+}