update README

README.md

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-# helloworld
-simple helloworld example build on NodeJS & Kubernetes
+
+# Node.js Express Server
+
+This is a simple Node.js application using the Express framework, Docker and Kubernetes. It provides basic health-check routes and retrieves system information such as IP addresses and hostname.
+
+## Features
+
+- **Health check endpoint** to verify the status of the application.
+- **System information endpoint** that returns the namespace, hostname, IP address, and a timestamp.
+- **Logging** with `morgan` to monitor HTTP requests.
+- Uses `os` module to retrieve network interface details.
+
+## Prerequisites
+
+- Node.js (v12.x or higher)
+- npm (v6.x or higher)
+
+## Installation
+
+1. Clone this repository.
+
+   ```bash
+   git clone <repository_url>
+   ```
+
+2. Navigate to the project directory.
+
+   ```bash
+   cd <project_directory>
+   ```
+
+3. Install the dependencies.
+
+   ```bash
+   npm install
+   ```
+
+## Environment Variables
+
+The application can use the following environment variables:
+
+- `PORT`: Port on which the server will listen (default is `9000`).
+- `MY_POD_NAMESPACE`: The namespace for the pod (defaults to `docker`).
+- `MY_POD_NAME`: The hostname of the pod (defaults to system hostname).
+- `MY_POD_IP`: The IP address of the pod (defaults to the machine's network interface addresses).
+
+## Usage
+
+1. To start the server, run the following command:
+
+   ```bash
+   node index.js
+   ```
+
+2. The application will be running on the port specified by the `PORT` environment variable (or `9000` by default).
+
+## API Endpoints
+
+### GET `/health`
+
+This endpoint returns the health status of the server.
+
+**Response:**
+
+```json
+{
+  "status": "ok",
+  "message": "we are up and running 😘"
+}
+```
+
+### GET `/`
+
+This endpoint returns system information such as the namespace, hostname, IP addresses, and a timestamp.
+
+**Response:**
+
+```json
+{
+  "status": "ok",
+  "namespace": "docker",
+  "hostname": "<hostname>",
+  "ip": [
+    { "eth0": "192.168.1.100" }
+  ],
+  "timestamp": 1684567890123
+}
+```
+
+## Logging
+
+The server uses the `morgan` library for request logging. Logs are printed in the console in the "dev" format.