Connecting with Node.js

This guide explains how to establish a connection between a Node.js application and a Redis database using the redis package. It walks through the necessary setup, configuration, and execution of a simple Redis command.

Variables

To successfully connect to a Redis instance, you’ll need to provide the following parameters. These can typically be found on the Elestio service overview page.

Variable	Description	Purpose
`HOST`	Redis hostname (from Elestio service overview)	The address of the server hosting your Redis instance.
`PORT`	Redis port (from Elestio service overview)	The port used for the Redis connection. The default Redis port is 6379.
`PASSWORD`	Redis password (from Elestio service overview)	Authentication key used to connect securely to the Redis instance.

Make sure to copy these values from the Elestio Redis service details and plug them into your code.

Prerequisites

Install Node.js and NPM

Check if Node.js is installed by running:

node -v

If not installed, download and install it from nodejs.org.
Confirm npm is installed by running:

npm -v

Install the redis Package

The redis package enables communication between Node.js applications and Redis.

npm install redis --save

Code

Create a new file named redis.js and add the following code:

const redis = require("redis");

// Redis connection configuration
const config = {
  socket: {
    host: "HOST",
    port: PORT,
  },
  password: "PASSWORD",
};

// Create a Redis client
const client = redis.createClient(config);

// Handle connection errors
client.on("error", (err) => {
  console.error("Redis connection error:", err);
});

// Connect and run a test command
(async () => {
  try {
    await client.connect();
    console.log("Connected to Redis");

    // Set and retrieve a test key
    await client.set("testKey", "Hello Redis");
    const value = await client.get("testKey");
    console.log("Retrieved value:", value);

    // Disconnect from Redis
    await client.disconnect();
  } catch (err) {
    console.error("Redis operation failed:", err);
  }
})();

To execute the script, open the terminal or command prompt and navigate to the directory where redis.js is located. Once in the correct directory, run the script with the command:

node redis.js

If the connection is successful, the output should resemble:

Connected to Redis  
Retrieved value: Hello Redis