Add middleware to check database connection, handle errors from conne…

…ction pool

src/daily-do-it.ts

@@ -23,6 +23,7 @@ import {
 import { configureHandlebars } from "./helpers/configure-handlebars.js";
 import { configureProxySupport } from "./helpers/proxy.js";
 import { configureErrorMonitoring } from "./helpers/configure-error-monitoring.js";
+import { dbConnectionTest } from "./middleware/db-connection-test.js";
 
 configureErrorMonitoring();
 
@@ -38,6 +39,7 @@ app.use(Sentry.Handlers.requestHandler());
 app.use(
   express.static(fileURLToPath(new URL(".", import.meta.url) + "public")),
 );
+app.use(dbConnectionTest);
 app.use(sessionMiddleware);
 app.use(passport.session());
 app.use(helmetMiddleware);

src/lib/db.ts

@@ -8,3 +8,7 @@ export const pool = new pg.Pool({
   password: ENV.DB_PASSWORD,
   port: ENV.DB_PORT,
 });
+
+pool.on("error", (err) => {
+  console.error(err);
+});

src/middleware/db-connection-test.ts

@@ -0,0 +1,20 @@
+import type { Request, Response, NextFunction } from "express";
+import { pool } from "../lib/db.js";
+
+/**
+ * A Simple database connection checker middleware, tests the
+ * database can be connected to and handles connection errors.
+ */
+export async function dbConnectionTest(
+  req: Request<{}, {}, {}, { async?: "true" | "false" }>,
+  res: Response,
+  next: NextFunction,
+) {
+  try {
+    const connection = await pool.connect();
+    connection.release();
+    next();
+  } catch {
+    next(new Error("Unable to connect to Database"));
+  }
+}