README

PHP library for correlation ids guzzle middleware based on the correlation ids library.

Table of contents

• Installation
• Principles
• Usage
• Tests

Installation

$ composer require oat-sa/lib-correlation-ids-guzzle

Principles

This library provides a ready to use guzzle middleware that forwards, as request headers, the correlation ids fetched from the correlation ids registry.

Notes

• the current process correlation id will be forwarded as the parent one,
• the root correlation id will be also forwarded.

More details about calls chaining available on the correlation ids library documentation.

Usage

With the provided factory

The GuzzleClientFactory creates for you a guzzle client with the middleware already enabled:

<?php declare(strict_types=1);

use OAT\Library\CorrelationIds\Registry\CorrelationIdsRegistry;
use OAT\Library\CorrelationIds\Registry\CorrelationIdsRegistryInterface;
use OAT\Library\CorrelationIdsGuzzle\Factory\GuzzleClientFactory;
use OAT\Library\CorrelationIdsGuzzle\Middleware\CorrelationIdsGuzzleMiddleware;

/** @var CorrelationIdsRegistryInterface $registry */
$registry = new CorrelationIdsRegistry(...);

$clientFactory = new GuzzleClientFactory(new CorrelationIdsGuzzleMiddleware($registry)));

$client = $clientFactory->create(['some' => 'options']);

...

$client->request('GET', 'http://example.com'); // Will forward correlation ids as request headers automatically.

Manually

You need to push the CorrelationIdsGuzzleMiddleware to your handler stack as follow:

<?php declare(strict_types=1);

use GuzzleHttp\Client;
use GuzzleHttp\HandlerStack;
use GuzzleHttp\Middleware;
use OAT\Library\CorrelationIds\Registry\CorrelationIdsRegistry;
use OAT\Library\CorrelationIds\Registry\CorrelationIdsRegistryInterface;
use OAT\Library\CorrelationIdsGuzzle\Middleware\CorrelationIdsGuzzleMiddleware;

/** @var CorrelationIdsRegistryInterface $registry */
$registry = new CorrelationIdsRegistry(...);

$handlerStack = HandlerStack::create();
$handlerStack->push(Middleware::mapRequest(new CorrelationIdsGuzzleMiddleware($registry)));

$client = new Client(['handler' => $handlerStack]);

...

$client->request('GET', 'http://example.com'); // Will forward correlation ids as request headers automatically.

Note: you can customize the log context key names by providing you own CorrelationIdsHeaderNamesProviderInterface implementation and pass it to the CorrelationIdsGuzzleMiddleware constructor.

Tests

To run tests:

$ vendor/bin/phpunit

Note: see phpunit.xml.dist for available test suites.