From 5fd91a96e8e45fc6e012cceaead46851b630774f Mon Sep 17 00:00:00 2001
From: Slawomir Koszewski <slawek@koszewscy.waw.pl>
Date: Sun, 19 Apr 2026 23:10:40 +0200
Subject: [PATCH] feat: add health check script and update Dockerfile for
 health check integration

---
 Dockerfile     |  4 +++-
 healthcheck.js | 39 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 42 insertions(+), 1 deletion(-)
 create mode 100644 healthcheck.js

diff --git a/Dockerfile b/Dockerfile
index f345109..98f291a 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -26,7 +26,9 @@ COPY --from=build /app/backend/node_modules dist/backend/node_modules
 
 WORKDIR /app
 COPY entrypoint.sh entrypoint.sh
+COPY healthcheck.js healthcheck.js
 RUN chmod +x entrypoint.sh
 
 EXPOSE 3000
-CMD ["./entrypoint.sh"]
+HEALTHCHECK --interval=30s --timeout=5s --start-period=15s --retries=3 CMD ["node", "/app/healthcheck.js"]
+ENTRYPOINT ["./entrypoint.sh"]
diff --git a/healthcheck.js b/healthcheck.js
new file mode 100644
index 0000000..9febd4a
--- /dev/null
+++ b/healthcheck.js
@@ -0,0 +1,39 @@
+#!/usr/bin/env node
+"use strict";
+
+const http = require("node:http");
+
+const port = Number.parseInt(process.env.PORT || "3000", 10);
+const path = process.env.HEALTHCHECK_PATH || "/api/templates";
+const timeoutMs = Number.parseInt(process.env.HEALTHCHECK_TIMEOUT_MS || "3000", 10);
+
+const req = http.request(
+  {
+    host: "127.0.0.1",
+    port,
+    path,
+    method: "GET",
+    timeout: timeoutMs
+  },
+  (res) => {
+    // Drain the response so the socket can close cleanly.
+    res.resume();
+
+    if (res.statusCode && res.statusCode >= 200 && res.statusCode < 400) {
+      process.exit(0);
+      return;
+    }
+
+    process.exit(1);
+  }
+);
+
+req.on("timeout", () => {
+  req.destroy(new Error("healthcheck timeout"));
+});
+
+req.on("error", () => {
+  process.exit(1);
+});
+
+req.end();