Integrate OpenTelemetry into a PHP application without writing any code.

Open Telemetry is a robust framework that offers observability for applications by collecting and exporting telemetry data, and zero-code instrumentation allows you to gain valuable insights into application performance with minimal changes to your existing codebase.

Prerequisites

• AWS Account with Ubuntu machine.

• PHP, PECL, composer installed.

Update the package list.

sudo apt update

Install the command-line interface for PHP 8.3 using the package manager.

sudo apt install php8.3-cli

Ensure the installation is correct.

php -v

Install PECL to get the tools needed for PHP extension development.

sudo apt install php-pear php8.3-dev

Download and install Composer, a dependency manager for PHP that makes managing libraries easier.

curl -sS https://getcomposer.org/installer | php

Move the Composer binary to a directory in /usr/local/bin/ to make it accessible globally.

sudo mv composer.phar /usr/local/bin/composer

Check the Composer version to verify the installation.

composer -v

Install build tools needed for creating PECL extensions.

sudo apt-get install gcc make autoconf

Create a PHP project using the Slim Framework.

Create a new project directory.

mkdir opentelemetry-php-example

Navigate to the directory.

cd opentelemetry-php-example

Initialize a new Composer project and add Slim as a dependency.

composer init --no-interaction --require slim/slim:"^4" --require slim/psr7:"^1"

Install the dependencies defined in composer.json using the following command.

composer update

Create the Application File

Create an index.php file with a basic Slim application.

nano index.php

Add the following code to it.

<?php
use Psr\Http\Message\ResponseInterface as Response;
use Psr\Http\Message\ServerRequestInterface as Request;
use Slim\Factory\AppFactory;

require __DIR__ . '/vendor/autoload.php';

$app = AppFactory::create();

$app->get('/rolldice', function (Request $request, Response $response) {
    $result = random_int(1,6);
    $response->getBody()->write(strval($result));
    return $response;
});

$app->run();

Explanation of the code:

1. The code imports necessary classes and loads dependencies with Composer, then initializes a new Slim application instance using the $app variable to manage routes and handle HTTP requests.

2. Define the /rolldice Route: Sets up a /rolldice route that generates a random number between 1 and 6, adds it to the response, and sends it back to the client.

3. Run the Application Starts the application and listens for incoming requests.

Now, start the built-in PHP server to test your application using the following command..

php -S 0.0.0.0:8080

Open http://<Public-IP-Address>:8080/rolldice in your browser to see a random number between 1 and 6.

Integrate OpenTelemetry into a PHP application without writing any additional code using zero-code instrumentation.

Update the PECL channel to obtain the latest available extensions.

sudo pecl channel-update pecl.php.net

Use PECL to install the OpenTelemetry PHP extension.

sudo pecl install opentelemetry

After installing the OpenTelemetry extension, enable it in your PHP configuration (php.ini).

sudo nano /etc/php/8.3/cli/php.ini

Add the following code to it.

[opentelemetry]
extension=opentelemetry.so

Verify that the extension is installed and enabled.

php --ri opentelemetry

Install necessary packages for automatic instrumentation.

composer config allow-plugins.php-http/discovery false
composer require open-telemetry/sdk open-telemetry/opentelemetry-auto-slim

Start the PHP server with OpenTelemetry enabled.

Start the application with OpenTelemetry environment variables to display trace output in the console.

env OTEL_PHP_AUTOLOAD_ENABLED=true \
    OTEL_TRACES_EXPORTER=console \
    OTEL_METRICS_EXPORTER=none \
    OTEL_LOGS_EXPORTER=none \
    php -S 0.0.0.0:8080

Open http://<Public-IP-Address>:8080/rolldice in your browser and refresh the page.

Accessing the application will display trace information in the console, confirming that OpenTelemetry is capturing telemetry data.