feat: initial backend service template

src/routes/root.ts

@@ -0,0 +1,39 @@
+import { Router } from "express";
+import { hostname } from "node:os";
+import type { Config } from "../lib/config.js";
+import type { Db } from "../lib/db.js";
+import type { Cache } from "../lib/redis.js";
+
+export function rootRouter(deps: {
+  config: Config;
+  db?: Db;
+  cache?: Cache;
+}): Router {
+  const router = Router();
+
+  router.get("/", async (_req, res, next) => {
+    try {
+      const body: Record<string, unknown> = {
+        service: deps.config.SERVICE_NAME,
+        version: deps.config.GIT_SHA,
+        pod: hostname(),
+      };
+      if (deps.db) {
+        const r = await deps.db.query(
+          "SELECT id, name, created_at FROM service_info ORDER BY id LIMIT 1",
+        );
+        body.db = r.rows[0] ?? null;
+      }
+      if (deps.cache) {
+        body.cacheHits = await deps.cache.incr(
+          `${deps.config.SERVICE_NAME}:hits`,
+        );
+      }
+      res.json(body);
+    } catch (err) {
+      next(err);
+    }
+  });
+
+  return router;
+}