Work with credential providers

A credential provider is a function that returns a GuzzleHttp\Promise\PromiseInterface that is fulfilled with an Aws\Credentials\CredentialsInterface instance or rejected with an Aws\Exception\CredentialsException. The SDK provides several implementations of credential provider functions or you can implement your own custom logic for creating credentials or to optimize credential loading.

Credential providers are passed into the credentials client constructor option. Credential providers are asynchronous, which forces them to be lazily evaluated each time an API operation is invoked. As such, passing in a credential provider function to an SDK client constructor doesn’t immediately validate the credentials. If the credential provider doesn’t return a credentials object, an API operation will be rejected with an Aws\Exception\CredentialsException.

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

// Use the ECS credential provider. 
$provider = CredentialProvider::ecsCredentials();
// Be sure to memoize the credentials.
$memoizedProvider = CredentialProvider::memoize($provider);

// Pass the provider to the client
$client = new S3Client([
    'region'      => 'us-west-2',
    'version'     => '2006-03-01',
    'credentials' => $memoizedProvider
]);