Response logging in AWS PHP SDK v3 - php

Question

In v2 of the AWS PHP SDK, I was able to setup logging of request and response information by simply doing this:
<?php
use Monolog\Logger;
use Guzzle\Log\MonologLogAdapter;
use Guzzle\Plugin\Log\LogPlugin;
use Aws\S3\S3Client;
$monolog = new Logger('main');
$monolog_adapter = new MonologLogAdapter($monolog);
$log_plugin = new LogPlugin($monolog_adapter);
$s3_client = S3Client::factory(['region' => 'us-east-1']);
$s3_client->addSubscriber($log_plugin);
var_dump($s3_client->doesObjectExist('my-bucket', 'object-that-doesnt-exist'));
# This is the log entry I want in the v3 version:
# [2015-10-30 14:47:20] main.ERROR: myhostname aws-sdk-php2/2.8.20 Guzzle/3.9.3 curl/7.43.0 PHP/5.5.23 - [2015-10-30T14:47:20+00:00] "HEAD /my-bucket/object-that-doesnt-exist HTTP/1.1" 404 ...
# bool(false)
In v3, I cannot seem to find the solution. Middlewares do not seem helpful as they only fire before the request is sent, and thus I cannot access the response HTTP code.
Guzzle v6 has this feature built into its Middlewares, but I do not know how to get it to work with the aws-php-sdk. https://github.com/guzzle/guzzle/blob/master/src/Middleware.php#L180
The closest I got was this:
<?php
use Monolog\Logger;
use GuzzleHttp\MessageFormatter;
use GuzzleHttp\Middleware;
use GuzzleHttp\HandlerStack;
use Aws\S3\S3Client;
$monolog = new Logger('main');
$guzzle_formatter = new MessageFormatter(MessageFormatter::CLF);
$guzzle_log_middleware = Middleware::log($monolog, $guzzle_formatter);
$guzzle_stack = HandlerStack::create();
$guzzle_stack->push($guzzle_log_middleware);
$s3_client = new S3Client([
'region' => 'us-east-1',
'version' => '2006-03-01',
'http_handler' => $guzzle_stack,
]);
var_dump($s3_client->doesObjectExist('my-bucket', 'object-that-doesnt-exist'));
# [2015-10-30 15:10:12] main.INFO: myhostname aws-sdk-php/3.9.2 - [30/Oct/2015:15:10:12 +0000] "HEAD /my-bucket/object-that-doesnt-exist HTTP/1.1" 404 [] []
# bool(true)
However, while the logging works, doesObjectExist() now returns the incorrect value because this handler does not throw an exception for 404, which the aws-php-sdk expects to happen. Some other simple requests like uploading to S3 seemed to work at first glance. Not sure where else there could be issues with this method.

Answer 1

The handler used in the SDK is a bit different from the one used in Guzzle. You're creating a Guzzle handler correctly, and to pass that into the SDK, you would need to create an adapter like so:
<?php
use Aws\Handler\GuzzleV6\GuzzleHandler;
use Aws\S3\S3Client;
use Monolog\Logger;
use GuzzleHttp\Client;
use GuzzleHttp\MessageFormatter;
use GuzzleHttp\Middleware;
use GuzzleHttp\HandlerStack;
$guzzle_stack = HandlerStack::create();
$guzzle_stack->push(Middleware::log(
new Logger('main'),
new MessageFormatter(MessageFormatter::CLF)
));
$handler = new GuzzleHandler(new Client(['handler' => $guzzle_stack]));
$s3_client = new S3Client([
'region' => 'us-east-1',
'version' => '2006-03-01',
'http_handler' => $handler,
]);
var_dump($s3_client->doesObjectExist('my-bucket', 'object-that-doesnt-exist'));
The GuzzleHandler object converts HTTP errors to exceptions.

Answer 2

With aws/aws-sdk-php 3.212.7, registering a custom logger as shown by #giaour did not work for me.
The configuration supports a debug key now:
$s3_client = new S3Client([
'region' => 'us-east-1',
'version' => '2006-03-01',
'debug' => true,
]);
This shows the data transferred, but not the URLs used.