Get an object's ACL

View the access control list (ACL) for an object in a Cloud Storage bucket.

Explore further

For detailed documentation that includes this code sample, see the following:

• Create and manage access control lists (ACLs)

Code sample

C++

For more information, see the Cloud Storage C++ API reference documentation.

To authenticate to Cloud Storage, set up Application Default Credentials. For more information, see Set up authentication for client libraries.

namespace gcs = ::google::cloud::storage;
using ::google::cloud::StatusOr;
[](gcs::Client client, std::string const& bucket_name,
   std::string const& object_name) {
  StatusOr<std::vector<gcs::ObjectAccessControl>> items =
      client.ListObjectAcl(bucket_name, object_name);

  if (!items) throw std::move(items).status();
  std::cout << "ACLs for object=" << object_name << " in bucket "
            << bucket_name << "\n";
  for (gcs::ObjectAccessControl const& acl : *items) {
    std::cout << acl.role() << ":" << acl.entity() << "\n";
  }
}

C#

For more information, see the Cloud Storage C# API reference documentation.

To authenticate to Cloud Storage, set up Application Default Credentials. For more information, see Set up authentication for client libraries.

using Google.Apis.Storage.v1.Data;
using Google.Cloud.Storage.V1;
using System;
using System.Collections.Generic;

public class PrintFileAclSample
{
    public IEnumerable<ObjectAccessControl> PrintObjectAcl(
        string bucketName = "your-unique-bucket-name",
        string objectName = "your-object-name")
    {
        var storage = StorageClient.Create();
        var storageObject = storage.GetObject(bucketName, objectName, new GetObjectOptions
        {
            Projection = Projection.Full
        });

        foreach (var acl in storageObject.Acl)
        {
            Console.WriteLine($"{acl.Role}:{acl.Entity}");
        }

        return storageObject.Acl;
    }
}

Go

For more information, see the Cloud Storage Go API reference documentation.

To authenticate to Cloud Storage, set up Application Default Credentials. For more information, see Set up authentication for client libraries.

import (
	"context"
	"fmt"
	"io"

	"cloud.google.com/go/storage"
)

// printFileACL lists ACL of the specified object.
func printFileACL(w io.Writer, bucket, object string) error {
	// bucket := "bucket-name"
	// object := "object-name"
	ctx := context.Background()
	client, err := storage.NewClient(ctx)
	if err != nil {
		return fmt.Errorf("storage.NewClient: %w", err)
	}
	defer client.Close()

	rules, err := client.Bucket(bucket).Object(object).ACL().List(ctx)
	if err != nil {
		return fmt.Errorf("ACLHandle.List: %w", err)
	}
	for _, rule := range rules {
		fmt.Fprintf(w, "ACL rule: %v\n", rule)
	}
	return nil
}

Java

For more information, see the Cloud Storage Java API reference documentation.

To authenticate to Cloud Storage, set up Application Default Credentials. For more information, see Set up authentication for client libraries.

import com.google.cloud.storage.Acl;
import com.google.cloud.storage.Blob;
import com.google.cloud.storage.BlobId;
import com.google.cloud.storage.Storage;
import com.google.cloud.storage.StorageOptions;
import java.util.List;

public class PrintFileAcl {

  public static void printFileAcl(String bucketName, String blobName) {

    // The ID to give your GCS bucket
    // String bucketName = "your-unique-bucket-name";

    // The name of the blob/file that you wish to view Acls of
    // String blobName = "your-blob-name";

    Storage storage = StorageOptions.newBuilder().build().getService();
    Blob blob = storage.get(BlobId.of(bucketName, blobName));
    List<Acl> blobAcls = blob.getAcl();

    for (Acl acl : blobAcls) {

      // This will give you the role.
      // See https://cloud.google.com/storage/docs/access-control/lists#permissions
      String role = acl.getRole().name();

      // This will give you the Entity type (i.e. User, Group, Project etc.)
      // See https://cloud.google.com/storage/docs/access-control/lists#scopes
      String entityType = acl.getEntity().getType().name();

      System.out.printf("%s: %s %n", role, entityType);
    }
  }
}

Node.js

For more information, see the Cloud Storage Node.js API reference documentation.

To authenticate to Cloud Storage, set up Application Default Credentials. For more information, see Set up authentication for client libraries.

/**
 * TODO(developer): Uncomment the following lines before running the sample.
 */
// The ID of your GCS bucket
// const bucketName = 'your-unique-bucket-name';

// The ID of your GCS file
// const fileName = 'your-file-name';

// Imports the Google Cloud client library
const {Storage} = require('@google-cloud/storage');

// Creates a client
const storage = new Storage();

async function printFileAcl() {
  // Gets the ACL for the file
  const [acls] = await storage.bucket(bucketName).file(fileName).acl.get();

  acls.forEach(acl => {
    console.log(`${acl.role}: ${acl.entity}`);
  });
}

printFileAcl().catch(console.error);

PHP

For more information, see the Cloud Storage PHP API reference documentation.

To authenticate to Cloud Storage, set up Application Default Credentials. For more information, see Set up authentication for client libraries.

use Google\Cloud\Storage\StorageClient;

/**
 * Print all entities and roles for an object's ACL.
 *
 * @param string $bucketName The name of your Cloud Storage bucket.
 *        (e.g. 'my-bucket')
 * @param string $objectName The name of your Cloud Storage object.
 *        (e.g. 'my-object')
 */
function get_object_acl(string $bucketName, string $objectName): void
{
    $storage = new StorageClient();
    $bucket = $storage->bucket($bucketName);
    $object = $bucket->object($objectName);
    $acl = $object->acl();
    foreach ($acl->get() as $item) {
        printf('%s: %s' . PHP_EOL, $item['entity'], $item['role']);
    }
}

Python

For more information, see the Cloud Storage Python API reference documentation.

To authenticate to Cloud Storage, set up Application Default Credentials. For more information, see Set up authentication for client libraries.

from google.cloud import storage


def print_blob_acl(bucket_name, blob_name):
    """Prints out a blob's access control list."""

    storage_client = storage.Client()
    bucket = storage_client.bucket(bucket_name)
    blob = bucket.blob(blob_name)

    for entry in blob.acl:
        print(f"{entry['role']}: {entry['entity']}")

Ruby

For more information, see the Cloud Storage Ruby API reference documentation.

To authenticate to Cloud Storage, set up Application Default Credentials. For more information, see Set up authentication for client libraries.

# The ID of your GCS bucket
# bucket_name = "your-unique-bucket-name"
# file_name   = "Name of a file in the Storage bucket"
# email       = "Google Cloud Storage ACL Entity email"

require "google/cloud/storage"

storage = Google::Cloud::Storage.new
bucket  = storage.bucket bucket_name
file    = bucket.file file_name

puts "ACL for #{file_name} in #{bucket_name}:"

file.acl.owners.each do |owner|
  puts "OWNER #{owner}"
end

file.acl.readers.each do |reader|
  puts "READER #{reader}"
end

What's next

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