Built-in credential providers in the Amazon SDK for PHP Version 3

The SDK provides several built-in credential providers that you can use individually or combine in a custom credential provider chain.

When you specify a credential provider during service client creation, the SDK attempts to load credentials by using only the specified credential provider. It does not use the default credential provider chain. If you know that you want a service client to use the instanceProfile provider, you can short-circuit the default chain by specifying the instanceProfile provider in the service client constructor:

use Aws\Credentials\CredentialProvider;
use Aws\S3\S3Client;

$provider = CredentialProvider::instanceProfile();
// Be sure to memoize the credentials
$memoizedProvider = CredentialProvider::memoize($provider);

$client = new S3Client([
    'region'      => 'us-west-2',
    'credentials' => $memoizedProvider  // The default credential provider chain is not used.
]);