README

pkerrigan\xray

A basic PHP instrumentation library for AWS X-Ray

Until Amazon releases an official PHP SDK for AWS X-Ray this library allows you to add basic instrumentation to PHP applications and report traces via the AWS X-Ray daemon.

Please note that no automatic instrumentation of popular libraries is provided. In order to instrument SQL queries, HTTP requests and/or other services you'll be required to create your own wrappers which start and end tracing segments as appropriate.

Installation

The recommended way to install this library is using Composer:

$ composer require pkerrigan/xray ^1

Usage

Starting a trace

The Trace class represents the top-level of an AWS X-Ray trace, and can function as a singleton for easy access from anywhere in your code, including before frameworks and dependency injectors have been initialised.

You should start a trace as early as possible in your request:

use Pkerrigan\Xray\Trace;

Trace::getInstance()
    ->setTraceHeader($_SERVER['HTTP_X_AMZN_TRACE_ID'] ?? null)
    ->setName('app.example.com')
    ->setUrl($_SERVER['REQUEST_URI'])
    ->setMethod($_SERVER['REQUEST_METHOD'])
    ->begin(); 

Adding a segment to a trace

You can add as many segments to your trace as necessary, including nested segments. To add an SQL query to your trace, you'd do the following:

Trace::getInstance()
    ->getCurrentSegment()
    ->addSubsegment(
        (new SqlSegment())
            ->setName('db.example.com')
            ->setDatabaseType('PostgreSQL')
            ->setQuery($mySanitisedQuery)    // Make sure to remove sensitive data before passing in a query
            ->begin()    
    );
    
    
// Run your query here
    
Trace::getInstance()
    ->getCurrentSegment()
    ->end();
    

The getCurrentSegment() method will always return the most recently opened segment, allowing you to nest as deeply as necessary.

Ending a trace

At the end of your request, you'll want to end and submit your trace. By default only submitting via the AWS X-Ray daemon is supported.

Trace::getInstance()
    ->end()
    ->setResponseCode(http_response_code())
    ->submit(new DaemonSegmentSubmitter());

Features not yet implemented

• Exception and stack trace support
• Submission of incomplete segments