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:

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.

Prerequisites

• Install PHP
  • Check if PHP is installed by running:

php -v

• • If not installed, download it from php.net and install.
• Install the phpredis Extension
  • The phpredis extension provides a native PHP interface for Redis. You can install it using:

sudo pecl install redis

• • Then enable it in your php.ini:

extension=redis

• • To verify it’s installed:

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