feat: app health endpoint succeeds (E00-S02-T03)

apps/server/Dockerfile

@@ -2,13 +2,14 @@
 
 # @personal-blog/server — EPPP public server application image.
 #
-# [E00-S02-T01] baseline: builds the workspace server package with the pinned
-# toolchain (Node 24.19.0 + pnpm 11.23.0, frozen lockfile) and runs the compiled
-# entrypoint. The server is still a bootstrap placeholder (its module loads and
-# exits cleanly); the Fastify 5 application shell that turns it into a serving
-# process lands in a later story, and the health gate (T02), health endpoint
-# (T03), volume persistence (T04), non-root/read-only hardening and multi-arch
-# targets are later E00-S02 tasks — all out of scope here.
+# [E00-S02-T01/T02/T03] baseline: builds the workspace server package with the
+# pinned toolchain (Node 24.19.0 + pnpm 11.23.0, frozen lockfile) and runs the
+# compiled entrypoint. Since T03 the entrypoint is a minimal Node `node:http`
+# server answering `GET /health` with `{"status":"ok"}` (HTTP 200) on port
+# 3000, so the app container stays up and the health endpoint succeeds. The
+# Fastify 5 application shell (and the real HTTP API) lands in a later story;
+# volume persistence (T04), non-root/read-only hardening (T05) and multi-arch
+# targets remain later E00-S02 tasks — all out of scope here.
 #
 # Image base: node:24.19.0-bookworm-slim (glibc Debian) per Technology-Stack
 # §5.4 — argon2 is a native dependency and musl/Alpine causes native-module

apps/server/package.json

@@ -3,12 +3,15 @@
   "version": "0.0.0",
   "private": true,
   "type": "module",
-  "description": "EPPP public server application. Bootstrap placeholder — the Fastify 5 application shell lands in a later story.",
+  "description": "EPPP public server application. Serves the application health endpoint (E00-S02-T03); the Fastify 5 application shell lands in a later story.",
   "scripts": {
     "build": "tsc -p tsconfig.json",
     "typecheck": "tsc -p tsconfig.json --noEmit",
     "start": "node dist/index.js"
   },
+  "devDependencies": {
+    "@types/node": "24.13.3"
+  },
   "main": "./dist/index.js",
   "types": "./dist/index.d.ts",
   "exports": {

apps/server/src/index.ts

@@ -1,8 +1,69 @@
 /**
  * @personal-blog/server — EPPP public server application.
  *
- * Bootstrap placeholder so apps/ is a real workspace package that compiles
- * under tsconfig.base.json. The Fastify 5 application shell (and its real
- * exports) lands in a later story.
+ * [E00-S02-T03] minimal serving process: a small HTTP server built on Node's
+ * `node:http` (no runtime dependencies yet) that answers the application
+ * health endpoint. `GET /health` reports a healthy application — HTTP 200 with
+ * `{"status":"ok"}` — so the Compose stack's `app` service stays up and the
+ * health endpoint succeeds once the stack is running.
+ *
+ * The Fastify 5 application shell (and the real HTTP API) lands in a later
+ * story; this bootstrap keeps the application health-checkable until then.
  */
-export {};
+
+import { createServer, type IncomingMessage, type ServerResponse } from 'node:http';
+
+/** Port the server listens on; `PORT` overrides the container default (3000). */
+const PORT = resolvePort(process.env.PORT);
+
+/** Health payload — reports a healthy application. */
+const HEALTH_PAYLOAD = JSON.stringify({ status: 'ok' });
+
+/** Payload for any route that is not the health endpoint. */
+const NOT_FOUND_PAYLOAD = JSON.stringify({ error: 'not found' });
+
+/**
+ * Resolves the listen port from `PORT` (default 3000, matching the Dockerfile
+ * `EXPOSE 3000` and the compose `:3000` container port). A non-numeric or
+ * out-of-range override falls back to the default so a bad `PORT` value cannot
+ * crash the process at startup.
+ */
+function resolvePort(raw: string | undefined): number {
+  const port = Number(raw ?? 3000);
+  return Number.isInteger(port) && port > 0 && port <= 65535 ? port : 3000;
+}
+
+/** Writes a JSON response with an explicit content-length. */
+function sendJson(res: ServerResponse, statusCode: number, body: string): void {
+  res.writeHead(statusCode, {
+    'Content-Type': 'application/json; charset=utf-8',
+    'Content-Length': Buffer.byteLength(body),
+  });
+  res.end(body);
+}
+
+/**
+ * Routes one request. The application only serves the health endpoint at this
+ * stage; anything else is a 404 so misconfiguration is loud.
+ */
+function handleRequest(req: IncomingMessage, res: ServerResponse): void {
+  if (req.method === 'GET' && (req.url ?? '/') === '/health') {
+    sendJson(res, 200, HEALTH_PAYLOAD);
+    return;
+  }
+  sendJson(res, 404, NOT_FOUND_PAYLOAD);
+}
+
+const server = createServer(handleRequest);
+
+server.listen(PORT, () => {
+  console.log(`@personal-blog/server listening on http://0.0.0.0:${PORT} (health: GET /health)`);
+});
+
+// `docker stop` (Compose down) and Ctrl-C send SIGTERM/SIGINT — close the
+// server and exit cleanly instead of being killed mid-request.
+for (const signal of ['SIGTERM', 'SIGINT'] as const) {
+  process.on(signal, () => {
+    server.close(() => process.exit(0));
+  });
+}

apps/server/tsconfig.json

@@ -2,7 +2,8 @@
   "extends": "../../tsconfig.base.json",
   "compilerOptions": {
     "rootDir": "src",
-    "outDir": "dist"
+    "outDir": "dist",
+    "types": ["node"]
   },
   "include": ["src"]
 }