Raspberry Pi Web Server

This is a simple Raspberry Pi-hosted web server written in Express and Node.js. The server serves a single-page application written in React and provides RESTful APIs for functionalities including:

• New user registration and user authentication
• Reading system information in real time
• Controlling GPIO pins and reading their states in real time

This project is the result of my ongoing effort to learn various web development technologies with emphasis on servers hosted on embedded Linux devices.

Installation & Setup

• Prerequisites

  • Make sure Node.js and npm are installed on the Raspberry Pi

  # 1. Clone the repository
  
  cd <project_dir>
  git clone https://github.com/Kadinata/raspi_web_server.git .
  
  
  # 2. If the project was cloned to a personal machine,
  # push the project contents to a Raspberry Pi
  
  rsync -avz --delete --exclude=node_modules --exclude=public --exclude=db --exclude=*.sh --exclude=coverage --exclude=__tests__ --exclude=app_data --exclude=.git -e ssh . <your raspberry pi>:<project dir>
  
  
  # 3. Login to the Raspberry Pi and install Node modules
  
  ssh <your raspberry pi>
  cd <project dir>
  node install
  
  
  # 4. Copy the single page app build 
  # Clone the web app from this repository: https://github.com/Kadinata/raspi_web_app
  # Run "npm run build" to build it and copy the contents of the build directory into this repo's public directory
  
  
  # 5. Launch the server
  node index.js

The final step should have launched a web server listening on port 3000 which serves the single page application. The page can be viewed at raspberrypi.local:3000

Tests

Use the following command to run all tests:

npm run test

Or to run tests on a specific file

npm run test -- <path to test file>

APIs

With the exception of the single page application, all API endpoints share the common /api/v1 root path. For example, the API endpoint for a new user registration is /api/v1/auth/register.

Auth Endpoints

Endpoint	Method	Body (JSON)	Requires Authentication?	Description
/auth/register	POST	username password	NO	Create a new user with the provided username and password and stores it in the database.
/auth/login	POST	username password	NO	Authenticate a user with the provided username and password. If authentication is successfull, a JSON Web Token bearing the user information is returned in the response.
/auth/user	GET	None	YES	Returns the current user information.
/auth/update_password	POST	username password newPassword	YES	Update the user's current password to the new password.

System Resources Information Endpoints

Endpoint	Method	Body (JSON)	Requires Authentication?	Description
/sysinfo	GET	None	YES	Returns a comprehensive snapshot of system resources information
/sysinfo/stream	GET	None	YES	Subscribe to a real-time system resources information stream

GPIO Endpoints

Endpoint	Method	Body (JSON)	Requires Authentication?	Description
/gpio	GET	None	YES	Returns the current state (logic level and direction) of all GPIO pins
/gpio	POST	*See notes	YES	Send commands to change the logic levels and/or directions of one or more GPIO pins
/gpio/usable_pins	GET	None	YES	Returns a list of controllable GPIO pin numbers
/gpio/stream	GET	None	YES	Subscribe to a real-time system GPIO pins status update stream

Notes:

• The /gpio POST endpoint takes an object with GPIO pin numbers as the key and control flag as the values. The first LSB of the control flag determines the logic level of the GPIO pin, and the second LSB determines the pin's direction. For example, { "2": 3, "4":2 } configures GPIO pin 2 to output and HIGH and GPIO pin 4 to output and LOW while leaving the other GPIO pins as they are.

Heartbeat (Keep Alive) Endpoints

Endpoint	Method	Body (JSON)	Requires Authentication?	Description
/heartbeat	GET	None	YES	Used by the SPA to detect connection loss

Technologies

Tools, frameworks, and libraries used in this project

Domain	Library / Framework
HTTP Server	Express, Node.js
Authentication	Passport.js, JSON Web Token
Database	SQLite3
Password Hashing	BCrypt
GPIO Control	onoff
Logging	Winston, Morgan
Testing	Jest.js, Supertest