fractalliter · April 28, 2024 19:31 · Apr 28, 2024 · Apr 28, 2024 · Apr 28, 2024
diff --git a/README.md b/README.md
@@ -71,4 +71,12 @@ We can easily check logs for the service in real-time via [journalctl](https://w
 journalctl -u hello-world.service -f
 ```
 
+You should see something like bellow if you send `curl localhost:3000/elias?github=fractalliter`:
+
+```text
+Apr 28 20:36:44 user-something systemd[1]: Started Hello world server.
+Apr 28 20:36:46 user-something ts-node[21800]: Server running at PORT:  3000
+Apr 28 20:36:57 user-something ts-node[21800]: request received param elias that queries {"github":"fractalliter"}
+```
+
 JournalCTL enables us to query the logs between dates and for specific log level like `error` or `info`.
diff --git a/index.ts b/index.ts
@@ -4,12 +4,12 @@ import express, { Request, Response } from "express";
 
 const app = express();
 
-app.use(express.json()) // for parsing application/json
-//
+app.use(express.json())
+
 const PORT = process.env.PORT;
 
 app.get("/:name", (request: Request, response: Response) => {
-    console.log(`request received param ${request.params.name} that queries ${JSON.stringify(request.query)}`);
+  console.log(`request received param ${request.params.name} that queries ${JSON.stringify(request.query)}`);
   response.status(200).send("Hello World");
 }); 
 

diff --git a/README.md b/README.md
@@ -0,0 +1,74 @@
+# Description
+
+[Systemd](https://systemd.io/) is a suite of basic building blocks for a Linux system. 
+It provides a system and service manager that runs as PID 1 and starts the rest of the system.
+There are cases that you want to run a script or job on a Linux server and keep track of the logs without an external library
+and also get the benfit of seamless control over the application lifecycle on the server. Systemd provides all of this out of the box.
+In this simple example I tried to demonstrate the use case with a simple [Express](https://expressjs.com/en/starter/hello-world.html) 
+hello world server that is developed in [Typescript](https://www.typescriptlang.org/) and [TS-Node](https://github.com/TypeStrong/ts-node).
+
+## Prerequisites
+
+- Nodejs
+- NPM
+
+## How to create systemd service
+
+You need to install Node in your Linux server and then install [ts-node](https://github.com/TypeStrong/ts-node) package:
+
+```bash
+# Or globally with TypeScript.
+npm install -g typescript
+npm install -g ts-node
+```
+
+Create a directory at `/usr/local/` for your app. you may need admin permission:
+
+```bash
+mkdir /usr/local/hello-world
+```
+Then change your direcotry to:
+
+```bash
+cd /usr/local/hello-world
+```
+
+You need to initialize your node project and install express library:
+
+```bash
+npm init -y
+
+npm i express
+npm i -D @types/express
+```
+
+you need to create `index.ts` file and copy/paste the content of the file into it. we are set with the script but
+we also need to create systemd service:
+
+```bash
+touch /etc/systemd/system/hello-world.service
+```
+
+and then copy/paste the content of `hello-server.service` file into it.
+
+We are also set with systemd service configruation.
+
+## How to run
+
+You are now able to execute the server under systemd services and control the status with systemd commands.
+
+```bash
+systemctl daemon-reload
+systemctl enable hello-world.service
+systemctl start hello-world.service
+```
+
+## How to see logs
+
+We can easily check logs for the service in real-time via [journalctl](https://www.freedesktop.org/software/systemd/man/latest/journalctl.html):
+
+```bash
+journalctl -u hello-world.service -f
+```
+
+JournalCTL enables us to query the logs between dates and for specific log level like `error` or `info`.
diff --git a/hello-server.service b/hello-server.service
@@ -0,0 +1,14 @@
+[Unit]
+Description=Hello world server
+After=network.target
+StartLimitIntervalSec=0
+
+[Service]
+Type=simple
+Restart=on-failure
+RestartSec=1
+ExecStart=/usr/bin/ts-node /usr/local/hello-world/index.ts
+Environment=PORT=3000
+
+[Install]
+WantedBy=multi-user.target
diff --git a/index.ts b/index.ts
@@ -0,0 +1,18 @@
+#!/usr/bin/ts-node
+
+import express, { Request, Response } from "express";
+
+const app = express();
+
+app.use(express.json()) // for parsing application/json
+//
+const PORT = process.env.PORT;
+
+app.get("/:name", (request: Request, response: Response) => {
+    console.log(`request received param ${request.params.name} that queries ${JSON.stringify(request.query)}`);
+  response.status(200).send("Hello World");
+}); 
+
+app.listen(PORT, () => { 
+  console.log("Server running at PORT: ", PORT); 
+})