Get an object ACL that's filtered by user

View the access control list (ACL) for an object in a Cloud Storage bucket that's filtered by user.

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 a local development environment.

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

  if (!acl) throw std::move(acl).status();
  std::cout << "ACL entry for " << acl->entity() << " in object "
            << acl->object() << " in bucket " << acl->bucket() << " is "
            << *acl << "\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 a local development environment.


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

public class PrintFileAclForUserSample
{
    public IEnumerable<ObjectAccessControl> PrintFileAclForUser(
        string bucketName = "your-unique-bucket-name",
        string objectName = "your-object-name",
        string userEmail = "user@iam.gserviceaccount.com")
    {
        var storage = StorageClient.Create();
        var storageObject = storage.GetObject(bucketName, objectName, new GetObjectOptions
        {
            Projection = Projection.Full
        });

        var fileAclForUser = storageObject.Acl.Where((acl) => acl.Entity == $"user-{userEmail}");
        foreach (var acl in fileAclForUser)
        {
            Console.WriteLine($"{acl.Role}:{acl.Entity}");
        }

        return fileAclForUser;
    }
}

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 a local development environment.

import (
	"context"
	"fmt"
	"io"

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

// printFileACLForUser lists ACL of the specified object with filter.
func printFileACLForUser(w io.Writer, bucket, object string, entity storage.ACLEntity) error {
	// bucket := "bucket-name"
	// object := "object-name"
	// entity := storage.AllAuthenticatedUsers
	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).ACL().List(ctx)
	if err != nil {
		return fmt.Errorf("ACLHandle.List: %w", err)
	}
	for _, r := range rules {
		if r.Entity == entity {
			fmt.Fprintf(w, "ACL rule role: %v\n", r.Role)
		}
	}
	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 a local development environment.


import com.google.cloud.storage.Acl;
import com.google.cloud.storage.Acl.User;
import com.google.cloud.storage.Blob;
import com.google.cloud.storage.BlobId;
import com.google.cloud.storage.Storage;
import com.google.cloud.storage.StorageOptions;

public class PrintFileAclForUser {

  public static void printFileAclForUser(String bucketName, String blobName, String userEmail) {

    // 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";

    // The email of the user whose acl is being retrieved.
    // String userEmail = "someuser@domain.com"

    Storage storage = StorageOptions.newBuilder().build().getService();
    Blob blob = storage.get(BlobId.of(bucketName, blobName));
    Acl blobAcl = blob.getAcl(new User(userEmail));
    if (blobAcl != null) {
      String userRole = blobAcl.getRole().name();
      System.out.println("User " + userEmail + " has role " + userRole);
    } else {
      System.out.println("User " + userEmail + " not found");
    }
  }
}

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 a local development environment.

/**
 * 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';

// The email address of the user to check
// const userEmail = 'user-email-to-check';

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

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

async function printFileAclForUser() {
  const options = {
    // Specify the user
    entity: `user-${userEmail}`,
  };

  // Gets the user's ACL for the file
  const [aclObject] = await storage
    .bucket(bucketName)
    .file(fileName)
    .acl.get(options);

  console.log(`${aclObject.role}: ${aclObject.entity}`);
}

printFileAclForUser().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 a local development environment.

use Google\Cloud\Storage\StorageClient;

/**
 * Print an entity role for a file 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')
 * @param string $entity The entity for which to query access controls.
 *        (e.g. 'user-example@domain.com')
 */
function print_file_acl_for_user(
    string $bucketName,
    string $objectName,
    string $entity
): void {
    $storage = new StorageClient();
    $bucket = $storage->bucket($bucketName);
    $object = $bucket->object($objectName);
    $acl = $object->acl();
    $item = $acl->get(['entity' => $entity]);
    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 a local development environment.

from google.cloud import storage


def print_blob_acl_for_user(bucket_name, blob_name, user_email):
    """Prints out a blob's access control list for a given user."""

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

    # Reload fetches the current ACL from Cloud Storage.
    blob.acl.reload()

    # You can also use `group`, `domain`, `all_authenticated` and `all` to
    # get the roles for different types of entities.
    roles = blob.acl.user(user_email).get_roles()

    print(roles)

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 a local development environment.

# 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 "Permissions for #{email}:"
puts "OWNER"  if file.acl.owners.include?  email
puts "READER" if file.acl.readers.include? email

What's next

To search and filter code samples for other Google Cloud products, see the Google Cloud sample browser.