Ismael Celis ismasan

How to set up a basic Sinatra + React webapp in 2025

Let's say you want to use Ruby for the backend of a basic webapp but React on the frontend. Here's how.

(Note: All tested on January 13, 2025 with Ruby 3.3, Sinatra 4.1.1, and React 18.3. Configs may change over time.)

First, create the app folder and set up Sinatra:

mkdir my-sinatra-react-app

A few lines of Ruby with pg driver is a simple alternative to a job queuing library. Job queues are defined as database tables and workers are defined in one Ruby file.

queuea: bundle exec ruby queue/a.rb
queueb: bundle exec ruby queue/b.rb

Let's Encrypt on Ubuntu 14.04, nginx with webroot auth

This document details how I setup LE on my server. Firstly, install the client as described on http://letsencrypt.readthedocs.org/en/latest/using.html and make sure you can execute it. I put it in /root/letsencrypt.

As it is not possible to change the ports used for the standalone authenticator and I already have a nginx running on port 80/443, I opted to use the webroot method for each of my domains (note that LE does not issue wildcard certificates by design, so you probably want to get a cert for www.example.com and example.com).

Configuration

For this, I placed config files into etc/letsencrypt/configs, named after <domain>.conf. The files are simple:

	/*
	This example demonstrates how a product price change can be rolled out with grace period for customers to order it for the previous price
	*/


	// little helper function to generate dates X minutes ago
	const minutesAgo = (minutes) => new Date((new Date).getTime() - minutes * (1000 * 60));

	const events = [
	{

	// 3D Dom viewer, copy-paste this into your console to visualise the DOM as a stack of solid blocks.
	// You can also minify and save it as a bookmarklet (https://www.freecodecamp.org/news/what-are-bookmarklets/)
	(() => {
	const SHOW_SIDES = false; // color sides of DOM nodes?
	const COLOR_SURFACE = true; // color tops of DOM nodes?
	const COLOR_RANDOM = false; // randomise color?
	const COLOR_HUE = 190; // hue in HSL (https://hslpicker.com)
	const MAX_ROTATION = 180; // set to 360 to rotate all the way round
	const THICKNESS = 20; // thickness of layers
	const DISTANCE = 10000; // ¯\\_(ツ)_/¯

	defmodule Client do
	def main(pid) do
	cmd = IO.gets("Enter a command: ") \|> String.trim()

	case String.split(cmd) do
	["show"] ->
	key = self()

	Task.async(fn ->
	send(pid, {:list, key, self()})

	/*
	* MIT License
	*
	* Copyright (c) 2023 Fabio Lima
	*
	* Permission is hereby granted, free of charge, to any person obtaining a copy
	* of this software and associated documentation files (the "Software"), to deal
	* in the Software without restriction, including without limitation the rights
	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	* copies of the Software, and to permit persons to whom the Software is

	module Commands
	module Meeting
	AcceptSchema = Dry::Validation.Schema do
	required(:user_id).filled
	required(:status).value(eql?: :scheduled)
	end

	class Accept < Command
	def call
	return validate if validate.failure?

	require 'result/ok'
	require 'result/error'

	#
	# A generic representation of success and failure.
	#
	# Styled after the Result monad of Elm and Rust
	# (or the Either monad of Haskell).
	#
	# The `#and_then` method can be used to chain functions that

	-- Enable pl/v8:
	CREATE EXTENSION plv8;

	-- Create json history table:
	CREATE TABLE json_history (id BIGSERIAL PRIMARY KEY, tstamp timestamp DEFAULT now(), table_name text, column_name text, target_id bigint, transform json);

	-- Create test table:
	CREATE TABLE test_json (id BIGSERIAL PRIMARY KEY, data JSON);

	-- Enable history tracking on test_json.data: