Building a Health Check Endpoint

A health endpoint reports whether a process is alive and whether its required dependencies are ready.

What It Does

A health endpoint reports whether a process is alive and whether its required dependencies are ready. The following examples distinguish a normal use case, a boundary case and a practical application.

Requirements and Compatibility

PHP 8.x and a local test environment. Apply input validation, correct error handling and the requirements of any optional libraries.

The code focuses on the core concept. Production implementation may also need routes, validation, persistence, authorization or deployment tooling.

Example 1: Basic Behavior

Understand the primary operation and its inputs.

<?php
function liveness(): array { return ['status' => 'ok']; }
echo json_encode(liveness(), JSON_THROW_ON_ERROR);

Example 2: Another Case

Check failure behavior or a different execution path.

<?php
$checks = ['database' => true, 'queue' => false];
$ready = !in_array(false, $checks, true);
echo $ready ? 'ready' : 'not ready';

Practical Example: Putting It to Use

Apply the behavior in a small, controlled scenario.

<?php
$status = ['ready' => true, 'timestamp' => gmdate('c')];
http_response_code($status['ready'] ? 200 : 503);
echo json_encode($status, JSON_THROW_ON_ERROR);

Important Behavior and Edge Cases

Do not expose secrets, full environment dumps or privileged database diagnostics through health URLs.

Comparison with Related Functions or Approaches

Common Beginner Mistakes

Key Takeaways

• A health endpoint reports whether a process is alive and whether its required dependencies are ready.
• Do not expose secrets, full environment dumps or privileged database diagnostics through health URLs.
• Separate liveness checks from readiness checks for deployment orchestrators.

Before adapting these examples, verify the return values, test the failure paths and confirm that your application meets its security and environment requirements.