Connecting with PHP

This guide explains how to establish a connection between a PHP application and a Redis database using the phpredis extension. It walks through the necessary setup, configuration, and execution of a simple Redis command.

Variables

Certain parameters must be provided to establish a successful connection to a Redis database. Below is a breakdown of each required variable, its purpose, and where to find it. Here’s what each variable represents:

Variable

Description

Purpose

HOST

Redis hostname, from the Elestio service overview page

The address of the server hosting your Redis instance.

PORT

Port for Redis connection, from the Elestio service overview page

The network port used to connect to Redis. The default port is 6379.

PASSWORD

Redis password, from the Elestio service overview page

The authentication key required to connect securely to Redis.

These values can usually be found in the Elestio service overview details as shown in the image below. Make sure to take a copy of these details and add it to the code moving ahead.

Screenshot 2025-05-19 at 12.23.05 PM.jpg

Prerequisites

php -v
sudo pecl install redis
extension=redis
php -m | grep redis

Code

Once all prerequisites are set up, create a new file named redis.php and add the following code:

<?php

$host = 'HOST';
$port = PORT;
$password = 'PASSWORD';

$redis = new Redis();

try {
    $redis->connect($host, $port);

    if (!$redis->auth($password)) {
        throw new Exception('Authentication failed');
    }

    echo "Connected to Redis\n";

    $redis->set("testKey", "Hello Redis");
    $value = $redis->get("testKey");
    echo "Retrieved value: $value\n";

    $redis->close();

} catch (Exception $e) {
    echo "Redis connection or operation failed: " . $e->getMessage() . "\n";
}

Open the terminal or command prompt and navigate to the directory where redis.php is located. Once in the correct directory, run the script with the command:

php redis.php

If the connection is successful, the terminal will display output similar to:

Connected to Redis  
Retrieved value: Hello Redis

Revision #1
Created 19 May 2025 12:38:40 by kaiwalya
Updated 19 May 2025 12:44:35 by kaiwalya