Covid Monitor Proxy

Covid Monitor Proxy delivers a small patient-monitoring dashboard backed by a lightweight Express proxy. The React interface periodically polls a remote API for the sickest patients, renders their vital signs, and lets clinicians focus on one patient at a time. The Node/Express server serves the production build and forwards API calls when the app is deployed behind a single origin.

Features

• Live polling dashboard – Start and stop continuous polling of the /users/sickest/:limit endpoint with a one-second interval.
• Patient severity list – Display incoming patients ranked by severity, colour-coded by score, and choose a patient to inspect.
• Vital sign cards – Show temperature, heart rate, blood pressure, and respiratory rate for the selected patient with iconography and unit labels.
• Configurable proxy – Express proxy forwards /api requests to the configured backend target, automatically binding to the detected interface if none is supplied.
• Container-ready – Multi-stage Dockerfile builds the React bundle and ships a minimal runtime image that runs the proxy server.

Project structure

.
├── public/           # Static assets consumed by Create React App
├── src/              # React application, contexts, widgets, and API service
├── server.js         # Express server that serves the build and proxies API calls
├── Dockerfile        # Multi-stage image that builds and runs the proxy server
├── package.json      # Dependencies and npm scripts
└── README.md         # Project documentation (this file)

Prerequisites

• Node.js 16+ (Node 18 is used in the Docker image)
• npm 7+

Installation

npm install

Configuration

Create a .env file in the project root (or export the variables in your shell) with the values appropriate for your environment.

Frontend build-time variables

Variable	Description	Example
REACT_APP_API_URL	Base URL for the monitoring API queried by Axios.	http://localhost:8000

Proxy runtime variables

Set these when running npm run server, the Docker container, or any deployment of the Express proxy.

Variable	Description	Default
API_TARGET	Destination base URL for proxied /api requests.	http://localhost:8000
BIND_IP	Local interface IP used by the proxy's HTTP agent. Autodetects a non-internal IPv4 address.	first detected IPv4 / 0.0.0.0
PORT	Port exposed by the Express server.	80

The proxy rewrites paths so that /api/users/sickest/:limit reaches ${API_TARGET}/users/sickest/:limit. Configure the frontend build to point either directly to the backend (via REACT_APP_API_URL) or to the proxy (REACT_APP_API_URL=/api).

Running locally

React development server

npm start

Runs react-scripts in development mode with hot reloading. Make sure REACT_APP_API_URL is reachable from the browser.

Tests

npm test

Launches the Jest test runner provided by Create React App in watch mode.

Production build

npm run build

Generates static assets under build/ that can be served by any static host or the bundled Express proxy.

Express proxy server

REACT_APP_API_URL=/api npm run build
API_TARGET=http://localhost:8000 PORT=8080 npm run server

The proxy serves the build/ directory and forwards /api requests to the backend target. BIND_IP is detected automatically and logged on startup.

API expectations

The React app expects a backend endpoint at /users/sickest/:limit that returns JSON in the following format:

{
  "data": [
    {
      "id": 1,
      "name": "Jane Doe",
      "score": 5,
      "temperature": 38.4,
      "heart_rate": 108,
      "blood_pressure": 120,
      "respiratory_rate": 24
    }
  ]
}

The polling limit is controlled by the numeric input on the dashboard and defaults to 0 until changed.

Docker workflow

Build and run the production image that bundles the compiled React app and proxy server.

docker build -t covid-monitor-proxy .
docker run --rm -p 8080:80 -e API_TARGET=http://backend:8000 covid-monitor-proxy

The runtime image installs common network troubleshooting tools (ping, curl, netstat) to aid diagnostics in constrained environments.

Contributing

1. Fork the repository.
2. Create a feature branch (git checkout -b feature/my-update).
3. Commit your work (git commit -am "Describe the change").
4. Push the branch (git push origin feature/my-update).
5. Open a Pull Request describing your changes.

License

This project is distributed under the MIT License. Update the license text if your organisation requires a different policy.