AWS s3 Listing Object Keys Using PHP - php

Question

I'm working on Listing Object Keys Using PHP using AWS s3.
I have the bucket setup with one test file loaded:
Screenshot of my s3 bucket with one test file
Here is the reference that I'm using from AWS documentation:
AWS ListingObjectKeysUsingPHP webpage
Here is the code that I'm using from the page:
<?php
require 'vendor/autoload.php';
use Aws\S3\S3Client;
use Aws\S3\Exception\S3Exception;
$bucket = 'apollos-integrations-public';
// Instantiate the client.
$s3 = new S3Client([
'version' => 'latest',
'region' => 'us-east-1'
]);
// Use the high-level iterators (returns ALL of your objects).
try {
$objects = $s3->getPaginator('ListObjects', [
'Bucket' => $bucket
]);
//var_dump($objects);
echo "Keys retrieved!" . PHP_EOL;
foreach ($objects as $object) {
echo $object['Key'] . PHP_EOL;
}
} catch (S3Exception $e) {
echo $e->getMessage() . PHP_EOL;
}
// Use the plain API (returns ONLY up to 1000 of your objects).
try {
$result = $s3->listObjects([
'Bucket' => $bucket
]);
echo "Keys retrieved!" . PHP_EOL;
foreach ($result['Contents'] as $object) {
echo $object['Key'] . PHP_EOL;
}
} catch (S3Exception $e) {
echo $e->getMessage() . PHP_EOL;
}
?>
When I execute this PHP script, it simply returns: "Keys retrieved!" without the test file listed. It should list the files in the folder.
When I add a "var_dump($objects);" (commented in the script, so when I uncomment it), then it returns a lot of data for the object as shown in this screenshot:
image for the object var dump
For some reason, this part of the code provided by Amazon is not working:
foreach ($objects as $object) {
echo $object['Key'] . PHP_EOL;
}
Why isn't this code provided by AWS working?
Shouldn't the key and secret be required?
Please help

Answer 1

Your problem was most likely caused by PHP AWS SDK not being able to get the credentials from your environment variables --> the credentials are either taken from environment variables, or you should specify them directly in your code like this:
// Instantiate the client.
$credentials = new Aws\Credentials\Credentials('<KEY>', '<SECRET>');
$s3 = new S3Client([
'version' => 'latest',
'region' => 'us-east-1',
'credentials' => $credentials
]);
(Replace '<KEY>' and '<SECRET>' with your credentials.). You can find the whole script bellow.
More information can be found here: https://docs.aws.amazon.com/sdk-for-php/v3/developer-guide/guide_configuration.html
Whole script (notice first two rows, where I enabled debugging info. This will show you error messages in case there is some problem - like in this case with the credentials):
<?php
error_reporting(-1);
ini_set('display_errors', 'On');
require 'vendor/autoload.php';
use Aws\S3\S3Client;
use Aws\S3\Exception\S3Exception;
$bucket = 'apollos-integrations-public';
// Instantiate the client.
$credentials = new Aws\Credentials\Credentials('<KEY>', '<SECRET>');
$s3 = new S3Client([
'version' => 'latest',
'region' => 'us-east-1',
'credentials' => $credentials
]);
// Use the high-level iterators (returns ALL of your objects).
try {
$objects = $s3->getPaginator('ListObjects', [
'Bucket' => $bucket
]);
echo "Keys retrieved!" . PHP_EOL;
foreach ($objects as $object) {
echo $object['Key'] . PHP_EOL;
}
} catch (S3Exception $e) {
echo $e->getMessage() . PHP_EOL;
}
// Use the plain API (returns ONLY up to 1000 of your objects).
try {
$result = $s3->listObjects([
'Bucket' => $bucket
]);
echo "Keys retrieved!" . PHP_EOL;
foreach ($result['Contents'] as $object) {
echo $object['Key'] . PHP_EOL;
}
} catch (S3Exception $e) {
echo $e->getMessage() . PHP_EOL;
}
BTW. this is the error message which you would see if you enable debugging info:
Fatal error: Uncaught Aws\Exception\CredentialsException: Error retrieving credentials from the instance profile metadata server.
Hopefully you find it helpful.