Running PHP, Nginx, and MySQL with Docker Compose

Run separate web, PHP-FPM and database services with explicit service discovery and persistent database storage.

The objective is to understand the behavior and operational limits, not only the method name.

What It Does

Run separate web, PHP-FPM and database services with explicit service discovery and persistent database storage.

Prerequisites

Use a dedicated development environment and sample data. Where a snippet uses an injected connection, repository, request value or mailer, supply it from your own application setup.

Example 1: Basic Use

A focused working pattern for this topic. Names such as $pdo, $authContext and $repo represent dependencies provided by the application unless initialized in the snippet.

<?php
$dsn = 'mysql:host=' . (getenv('DB_HOST') ?: 'db') . ';dbname=app;charset=utf8mb4';
$db = new PDO($dsn, getenv('DB_USER'), getenv('DB_PASSWORD'));
echo $db->query('SELECT VERSION()')->fetchColumn();

Example 2: A Second Scenario

A second use case that adds a different operation or data flow specific to this topic.

<?php
$dbHost = getenv('DB_HOST') ?: 'db';
$dsn = "mysql:host=$dbHost;port=3306;dbname=app;charset=utf8mb4";
$pdo = new PDO($dsn, getenv('DB_USER'), getenv('DB_PASSWORD'));
echo $pdo->getAttribute(PDO::ATTR_DRIVER_NAME);

Example 3: Practical Checks

A practical validation, failure or deployment concern specific to this topic.

<?php
$trustedHost = getenv('DB_HOST');
if (!$trustedHost || $trustedHost === 'localhost') throw new RuntimeException('Use the Compose database service hostname');
$db = new PDO("mysql:host=$trustedHost;dbname=app;charset=utf8mb4", getenv('DB_USER'), getenv('DB_PASSWORD'));

Important Behavior and Edge Cases

Use Docker secrets or environment injection for credentials and never publish the database port unnecessarily.

For production use, also account for error handling, data validation, resource limits and environment-specific driver behavior.

Comparison with Related Approaches

Common Beginner Mistakes

Key Takeaways

• Run separate web, PHP-FPM and database services with explicit service discovery and persistent database storage.
• Use Docker secrets or environment injection for credentials and never publish the database port unnecessarily.
• Use this workflow as a focused starting point rather than a substitute for application-level tests.

Choose this API or pattern when its exact semantics match your task, and verify the result against the database driver and runtime used by your application.