Getting Started

Get up and running with OpenTelemetry for PHP.

OpenTelemetry for PHP can be used to generate and export traces, metrics and logs.

This page will show you how to get started with OpenTelemetry in PHP. We will create a simple “roll the dice” application, then apply both zero-code and code based instrumentation to generate traces and export them to the console. We will then emit some logs which will also be sent to the console.

Prerequisites

OpenTelemetry requires PHP 8.0+ for zero-code instrumentation, however manual instrumentation will work with PHP 7.4

Ensure that you have the following installed:

Before you get started make sure that you have both available in your shell:

php -v
composer -v

Example Application

The following example uses a basic Slim Framework application. If you are not using Slim, that’s OK — you can use OpenTelemetry PHP with other web frameworks as well, such as WordPress, Symfony and Laravel. For a complete list of libraries for supported frameworks, see the registry.

Dependencies

In an empty directory initialize a minimal composer.json file:

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

Create and launch an HTTP Server

In that same directory, create a file called index.php with the following content:

<?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();

Run the application using the PHP built-in web server:

php -S localhost:8080

Open http://localhost:8080/rolldice in your web browser to ensure it is working.

Add zero-code instrumentation

Next, you’ll use the OpenTelemetry PHP extension to automatically instrument the application.

  1. Since the extension is built from source, you need to install some build tools

    sudo apt-get install gcc make autoconf

    brew install gcc make autoconf

  2. Build the extension with PECL:

    pecl install opentelemetry

  3. Add the extension to your php.ini file:

    [opentelemetry]
extension=opentelemetry.so

  4. Verify that the extension is installed and enabled:

    php --ri opentelemetry

  5. Add additional dependencies to your application, which are required for the automatic instrumentation of your code:

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

With the OpenTelemetry PHP extension set up and an instrumentation library installed, you can now run your application and generate some traces:

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

Open http://localhost:8080/rolldice in your web browser and reload the page a few times. After a while you should see the spans printed to your console:

View example output
[
  {
    "name": "GET /rolldice",
    "context": {
      "trace_id": "16d7c6da7c021c574205736527816eb7",
      "span_id": "268e52331de62e33",
      "trace_state": ""
    },
    "resource": {
      "service.name": "__root__",
      "service.version": "1.0.0+no-version-set",
      "telemetry.sdk.name": "opentelemetry",
      "telemetry.sdk.language": "php",
      "telemetry.sdk.version": "1.0.0beta10",
      "telemetry.auto.version": "1.0.0beta5",
      "process.runtime.name": "cli-server",
      "process.runtime.version": "8.2.6",
      "process.pid": 24435,
      "process.executable.path": "/bin/php",
      "process.owner": "php",
      "os.type": "darwin",
      "os.description": "22.4.0",
      "os.name": "Darwin",
      "os.version": "Darwin Kernel Version 22.4.0: Mon Mar  6 20:59:28 PST 2023; root:xnu-8796.101.5~3/RELEASE_ARM64_T6000",
      "host.name": "OPENTELEMETRY-PHP",
      "host.arch": "arm64"
    },
    "parent_span_id": "",
    "kind": "KIND_SERVER",
    "start": 1684749478068582482,
    "end": 1684749478072715774,
    "attributes": {
      "code.function": "handle",
      "code.namespace": "Slim\\App",
      "code.filepath": "/vendor/slim/slim/Slim/App.php",
      "code.lineno": 197,
      "http.url": "http://localhost:8080/rolldice",
      "http.method": "GET",
      "http.request_content_length": "",
      "http.scheme": "http",
      "http.status_code": 200,
      "http.flavor": "1.1",
      "http.response_content_length": ""
    },
    "status": {
      "code": "Unset",
      "description": ""
    },
    "events": [],
    "links": []
  }
]

Add manual instrumentation

Traces

Manual tracing requires a TracerProvider. There are a number of ways to set one up. In this example we will use the autoloaded TracerProvider, which is globally available.

Replace index.php with the following code:

<?php

use OpenTelemetry\API\Globals;
use Psr\Http\Message\ResponseInterface as Response;
use Psr\Http\Message\ServerRequestInterface as Request;
use Slim\Factory\AppFactory;

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

$tracer = Globals::tracerProvider()->getTracer('demo');

$app = AppFactory::create();

$app->get('/rolldice', function (Request $request, Response $response) use ($tracer) {
    $span = $tracer
        ->spanBuilder('manual-span')
        ->startSpan();
    $result = random_int(1,6);
    $response->getBody()->write(strval($result));
    $span
        ->addEvent('rolled dice', ['result' => $result])
        ->end();
    return $response;
});

$app->run();

Start the built-in web server again, and browse to http://localhost:8080/rolldice. You should see similar output, but with the addition of a new span named manual-span.

Note that the manual span’s parent_span_id contains the same value as the “{closure}” span’s context.span_id. Manual and automatic instrumentation work well together, since under the hood they use the same APIs.

Logging

Now let’s add some logging. We will use the popular monolog logging library to do this, via a handler which will emit the logs in the OpenTelemetry format.

First, let’s install some more dependencies:

composer require \
  monolog/monolog \
  open-telemetry/opentelemetry-logger-monolog

Replace the index.php file with the following code:

<?php

use Monolog\Logger;
use OpenTelemetry\API\Globals;
use OpenTelemetry\Contrib\Logs\Monolog\Handler;
use Psr\Http\Message\ResponseInterface as Response;
use Psr\Http\Message\ServerRequestInterface as Request;
use Psr\Log\LogLevel;
use Slim\Factory\AppFactory;

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

$loggerProvider = Globals::loggerProvider();
$handler = new Handler(
    $loggerProvider,
    LogLevel::INFO
);
$monolog = new Logger('otel-php-monolog', [$handler]);

$app = AppFactory::create();

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

$app->run();

Start the built-in web server with the following command (note the change to OTEL_LOGS_EXPORTER):

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

This time when browsing to http://localhost:8080/rolldice you should see the automatic instrumentation traces as before, and also a log record which was generated from the monolog handler.

Note that trace_id and span_id were added to the log output, and that the values correspond to the active span at the time the log message was generated.

View example output
[
    {
        "name": "{closure}",
        "context": {
            "trace_id": "8b046fc5d43864058b6a5a18e0dfce3f",
            "span_id": "9cf24c78c6868bfe",
            "trace_state": ""
        },
        "resource": {
            "service.name": "__root__",
            "service.version": "1.0.0+no-version-set",
            "telemetry.sdk.name": "opentelemetry",
            "telemetry.sdk.language": "php",
            "telemetry.sdk.version": "1.0.0beta11",
            "telemetry.auto.version": "1.0.0beta6",
            "process.runtime.name": "cli-server",
            "process.runtime.version": "8.0.27",
            "process.pid": 2672,
            "process.executable.path": "\/usr\/local\/bin\/php",
            "process.owner": "root",
            "os.type": "linux",
            "os.description": "5.15.0-75-generic",
            "os.name": "Linux",
            "os.version": "#82-Ubuntu SMP Tue Jun 6 23:10:23 UTC 2023",
            "host.name": "f2c0afe83ea9",
            "host.arch": "x86_64"
        },
        "parent_span_id": "df2199a615085705",
        "kind": "KIND_INTERNAL",
        "start": 1687323704059486500,
        "end": 1687323704060820769,
        "attributes": {
            "code.function": "__invoke",
            "code.namespace": "Slim\\Handlers\\Strategies\\RequestResponse",
            "code.filepath": "\/usr\/src\/myapp\/vendor\/slim\/slim\/Slim\/Handlers\/Strategies\/RequestResponse.php",
            "code.lineno": 28
        },
        "status": {
            "code": "Unset",
            "description": ""
        },
        "events": [],
        "links": []
    }
]
[
    {
        "name": "GET \/rolldice",
        "context": {
            "trace_id": "8b046fc5d43864058b6a5a18e0dfce3f",
            "span_id": "df2199a615085705",
            "trace_state": ""
        },
        "resource": {
            "service.name": "__root__",
            "service.version": "1.0.0+no-version-set",
            "telemetry.sdk.name": "opentelemetry",
            "telemetry.sdk.language": "php",
            "telemetry.sdk.version": "1.0.0beta11",
            "telemetry.auto.version": "1.0.0beta6",
            "process.runtime.name": "cli-server",
            "process.runtime.version": "8.0.27",
            "process.pid": 2672,
            "process.executable.path": "\/usr\/local\/bin\/php",
            "process.owner": "root",
            "os.type": "linux",
            "os.description": "5.15.0-75-generic",
            "os.name": "Linux",
            "os.version": "#82-Ubuntu SMP Tue Jun 6 23:10:23 UTC 2023",
            "host.name": "f2c0afe83ea9",
            "host.arch": "x86_64"
        },
        "parent_span_id": "",
        "kind": "KIND_SERVER",
        "start": 1687323704058191192,
        "end": 1687323704060981779,
        "attributes": {
            "code.function": "handle",
            "code.namespace": "Slim\\App",
            "code.filepath": "\/usr\/src\/myapp\/vendor\/slim\/slim\/Slim\/App.php",
            "code.lineno": 197,
            "http.url": "http:\/\/localhost:8080\/rolldice",
            "http.method": "GET",
            "http.request_content_length": "",
            "http.scheme": "http",
            "http.status_code": 200,
            "http.flavor": "1.1",
            "http.response_content_length": ""
        },
        "status": {
            "code": "Unset",
            "description": ""
        },
        "events": [],
        "links": []
    }
]
{
    "resource": {
        "attributes": {
            "service.name": "__root__",
            "service.version": "1.0.0+no-version-set",
            "telemetry.sdk.name": "opentelemetry",
            "telemetry.sdk.language": "php",
            "telemetry.sdk.version": "1.0.0beta11",
            "telemetry.auto.version": "1.0.0beta6",
            "process.runtime.name": "cli-server",
            "process.runtime.version": "8.0.27",
            "process.pid": 2672,
            "process.executable.path": "\/usr\/local\/bin\/php",
            "process.owner": "root",
            "os.type": "linux",
            "os.description": "5.15.0-75-generic",
            "os.name": "Linux",
            "os.version": "#82-Ubuntu SMP Tue Jun 6 23:10:23 UTC 2023",
            "host.name": "f2c0afe83ea9",
            "host.arch": "x86_64"
        },
        "dropped_attributes_count": 0
    },
    "scope": {
        "name": "monolog",
        "version": null,
        "attributes": [],
        "dropped_attributes_count": 0,
        "schema_url": null,
        "logs": [
            {
                "timestamp": 1687323704059648000,
                "observed_timestamp": 1687323704060784128,
                "severity_number": 9,
                "severity_text": "INFO",
                "body": "dice rolled",
                "trace_id": "8b046fc5d43864058b6a5a18e0dfce3f",
                "span_id": "9cf24c78c6868bfe",
                "trace_flags": 1,
                "attributes": {
                    "channel": "otel-php-monolog",
                    "context": {
                        "result": 4
                    }
                },
                "dropped_attributes_count": 0
            }
        ]
    }
}

What’s next?

For more:


Last modified August 6, 2024: rework php zero-code page (#4952) (291ff16f)