How to manage the ACL of an object - Object Storage Service

This topic describes how to manage the access control list (ACL) of an Object Storage Service (OSS) object.

Usage notes

In this topic, the public endpoint of the China (Hangzhou) region is used. If you want to access OSS from other Alibaba Cloud services in the same region as OSS, use an internal endpoint. For more information about OSS regions and endpoints, see Regions, endpoints and open ports.
In this topic, an OSSClient instance is created by using an OSS endpoint. If you want to create an OSSClient instance by using custom domain names or Security Token Service (STS), see Create an OSSClient instance.
To configure the ACL of an object, you must have the oss:PutObjectAcl permission. To query the ACL of an object, you must have the oss:GetObjectAcl permission. For more information, see Attach a custom policy to a RAM user.

Types of ACLs

The following table describes the ACLs that you can configure for an object.

ACL	Description	Value
Inherited from bucket	The ACL of the object is the same as the ACL of the bucket in which the object is stored.	default
Private	Only the object owner and authorized users have read and write permissions on the object.	private
Public-read	Only the object owner and authorized users have read and write permissions on the object. Other users have only read permissions on the object. Exercise caution when you set the object ACL to this value.	public-read
Public-read-write	All users have read and write permissions on the object. Exercise caution when you set the object ACL to this value.	public-read-write

The ACL of an object takes precedence over the ACL of the bucket in which the object is stored. For example, if the ACL of a bucket is private and the ACL of an object that is stored in the bucket is public read/write, all users are granted the read and write permissions on the object. If the ACL of an object is not configured, the ACL of the object is the same as the ACL of the bucket in which the object is stored.

Configure the ACL of an object

The following sample code provides an example on how to configure the ACL of an object:

<?php
if (is_file(__DIR__ . '/../autoload.php')) {
    require_once __DIR__ . '/../autoload.php';
}
if (is_file(__DIR__ . '/../vendor/autoload.php')) {
    require_once __DIR__ . '/../vendor/autoload.php';
}
use OSS\Credentials\EnvironmentVariableCredentialsProvider;
use OSS\OssClient;
use OSS\Core\OssException;

// Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured.  
$provider = new EnvironmentVariableCredentialsProvider();
// In this example, the endpoint of the China (Hangzhou) region is used. Specify your actual endpoint. 
$endpoint = "http://oss-cn-hangzhou.aliyuncs.com";
$bucket= "yourBucketName";
$object = "yourObjectName";
// Set the ACL of the object to public-read. If you do not specify the ACL of the object, the ACL of the object inherits the ACL of the bucket in which the object is stored. 
$acl = "public-read";
try {
    $config = array(
        "provider" => $provider,
        "endpoint" => $endpoint,
        "signatureVersion" => OssClient::OSS_SIGNATURE_VERSION_V4,
        "region"=> "cn-hangzhou"
    );
    $ossClient = new OssClient($config);

    $ossClient->putObjectAcl($bucket, $object, $acl);
} catch (OssException $e) {
    printf(__FUNCTION__ . ": FAILED\n");
    printf($e->getMessage() . "\n");
    return;
}
print(__FUNCTION__ . ": OK" . "\n");

Query the ACL of an object

The following sample code provides an example on how to query the ACL of an object:

<?php
if (is_file(__DIR__ . '/../autoload.php')) {
    require_once __DIR__ . '/../autoload.php';
}
if (is_file(__DIR__ . '/../vendor/autoload.php')) {
    require_once __DIR__ . '/../vendor/autoload.php';
}
use OSS\Credentials\EnvironmentVariableCredentialsProvider;
use OSS\OssClient;
use OSS\Core\OssException;

// Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured.  
$provider = new EnvironmentVariableCredentialsProvider();
// In this example, the endpoint of the China (Hangzhou) region is used. Specify your actual endpoint. 
$endpoint = "http://oss-cn-hangzhou.aliyuncs.com";
$bucket= "yourBucketName";
$object = "yourObjectName";
try {
    $config = array(
        "provider" => $provider,
        "endpoint" => $endpoint,
        "signatureVersion" => OssClient::OSS_SIGNATURE_VERSION_V4,
        "region"=> "cn-hangzhou"
    );
    $ossClient = new OssClient($config);

    $objectAcl = $ossClient->getObjectAcl($bucket, $object);
} catch (OssException $e) {
    printf(__FUNCTION__ . ": FAILED\n");
    printf($e->getMessage() . "\n");
    return;
}
print(__FUNCTION__ . ": OK" . "\n");
var_dump($objectAcl);