By Redis Team

Learn how to build with Redis Stack and Node.js 

This tutorial will show you how to build an API using Node.js and Redis Stack. 

We'll be using Express and Redis OM to do this, and we assume that you have a basic understanding of Express. 

The API we'll be building is a simple and relatively RESTful API that reads, writes, and finds data on persons: first name, last name, age, etc. We'll also add a simple location tracking feature just for a bit of extra interest. 

But before we start with the coding, let's start with a description of what Redis OM is.

Redis OM (pronounced REDiss OHM) is a library that provides object mapping for Redis—that's what the OM stands for... object mapping. It maps Redis data types — specifically Hashes and JSON documents — to JavaScript objects. And it allows you to search over these Hashes and JSON documents. It uses RedisJSON and RediSearch to do this.

RedisJSON and RediSearch are two of the modules included in Redis Stack. Modules are extensions to Redis that add new data types and new commands. RedisJSON adds a JSON document data type and the commands to manipulate it. RediSearch adds various search commands to index the contents of JSON documents and Hashes.

Redis OM comes in four different versions. We'll be working with Redis OM for Node.js in this tutorial, but there are also flavors and tutorials for Python, .NET, and Spring.

This tutorial will get you started with Redis OM for Node.js, covering the basics. But if you want to dive deep into all of Redis OM's capabilities, check out the README over on GitHub.

Prerequisites 

Like anything software-related, you need to have some dependencies installed before you can get started: 

Node.js 14.8+: In this tutorial, we're using JavaScript's top-level await feature which was introduced in Node 14.8. So, make sure you are using that version or later. 

Redis Stack: You need a version of Redis Stack, either running locally on your machine or in the cloud. 

RedisInsight: We'll use this to look inside Redis and make sure our code is doing what we think it's doing.

Starter code

We're not going to code this completely from scratch. Instead, we've provided some starter code for you. Go ahead and clone it to a folder of your convenience:

git clone git@github.com:redis-developer/express-redis-om-workshop.git

Now that you have the starter code, let's explore it a bit. Opening up server.js in the root we see that we have a simple Express app that uses Dotenv for configuration and Swagger UI Express for testing our API:

import 'dotenv/config'

import express from 'express'
import swaggerUi from 'swagger-ui-express'
import YAML from 'yamljs'

/* create an express app and use JSON */
const app = new express()
app.use(express.json())

/* set up swagger in the root */
const swaggerDocument = YAML.load('api.yaml')
app.use('/', swaggerUi.serve, swaggerUi.setup(swaggerDocument))

/* start the server */
app.listen(8080)

Alongside this is api.yaml, which defines the API we're going to build and provides the information Swagger UI Express needs to render its UI. You don't need to mess with it unless you want to add some additional routes. 

The persons folder has some JSON files and a shell script. The JSON files are sample persons—all musicians because fun—that you can load into the API to test it. The shell script—load-data.sh—will load all the JSON files into the API using curl. 

There are two empty folders, om and routers. The om folder is where all the Redis OM code will go. The routers folder will hold code for all of our Express routes.