Use uniform bucket-level access

Go to concepts

Important: Uniform bucket-level access was known as Bucket Policy Only during Beta. The organization policy and API fields referring to Bucket Policy Only are still supported, but we recommend using the equivalent uniform bucket-level access organization policy and API fields.

This page shows you how to enable, disable and check the status of uniform bucket-level access on a bucket in Cloud Storage.

Prerequisites

Before using this feature in Cloud Storage, you should:

1. Have sufficient permission to view and update buckets in Cloud Storage:

   • If you own the project that contains the bucket, you most likely have the necessary permissions.

   • You should have the storage.buckets.update and storage.buckets.get IAM permissions on the relevant bucket. See Using IAM Permissions for instructions on how to get a role, such as Storage Admin, that has these permissions.

Check for ACL usage

Before you enable uniform bucket-level access, use Cloud Monitoring to ensure your bucket is not using ACLs for any workflows. For more information, see Check object ACL usage.

Console

To use Metrics Explorer to view the metrics for a monitored resource, follow these steps:

1. In the Google Cloud console, go to the Metrics Explorer page within Monitoring.

Go to Metrics Explorer

2. In the toolbar, select the Explorer tab.
3. Select the Configuration tab.
4. Expand the Select a metric menu, enter ACLs usage in the filter bar, and then use the submenus to select a specific resource type and metric:
   1. In the Active resources menu, select GCS Bucket.
   2. In the Active metric categories menu, select Authz.
   3. In the Active metrics menu, select ACLs usage.
   4. Click Apply.
   The fully qualified name for this metric is storage.googleapis.com/authz/acl_operations_count..
5. Optional: To configure how the data is viewed, add filters and use the Group By, Aggregator, and chart-type menus. For example, to group the data by bucket and ACL operation, select acl_operation for Group By and sum for Aggregator. For more information, see Select metrics when using Metrics Explorer.
6. Optional: Change the graph settings:
   • For quota and other metrics that report one sample per day, set the time frame to at least one week and set the plot type to Stacked bar chart.
   • For distribution valued metrics, set the plot type to Heatmap chart.

See storage for a complete list of metrics available for Cloud Storage. For information about time series, see Metrics, time series, and resources.

JSON API

1. Get an authorization access token from the OAuth 2.0 Playground. Configure the playground to use your own OAuth credentials. For instructions, see API authentication.

2. Use cURL to call the Monitoring JSON API:

   curl \
   'https://monitoring.googleapis.com/v3/projects/PROJECT_ID/timeSeries?filter=metric.type%20%3D%20%22storage.googleapis.com%2Fauthz%2Facl_operations_count%22&interval.endTime=END_TIME&interval.startTime=START_TIME' \
   --header 'Authorization: Bearer OAUTH2_TOKEN' \
   --header 'Accept: application/json'
   

   Where:

   • PROJECT_ID is the project ID or number for which you want to view ACL usage. For example, my-project.
   • END_TIME is the end of the time range for which you want to view ACL usage. For example, 2019-11-02T15:01:23.045123456Z.
   • START_TIME is the start of the time range for which you want to view ACL usage. For example, 2016-10-02T15:01:23.045123456Z.
   • OAUTH2_TOKEN is the access token you generated in Step 1.

If the request returns an empty object {}, there is no recent ACL usage for your project.

Set uniform bucket-level access

Important: In order to disable uniform bucket-level access, the following must be true:

• The feature has been enabled for less than 90 consecutive days
• You have removed any IAM conditions from the bucket's IAM policy
• The bucket is not subject to the Require uniform bucket-level access organization policy constraint

To enable or disable uniform bucket-level access on your bucket:

Console

1. In the Google Cloud console, go to the Cloud Storage Buckets page.
   

   Go to Buckets

2. In the list of buckets, click on the name of the desired bucket.

3. Select the Permissions tab near the top of the page.

4. In the text box named Access Control, click the Switch to link. Note that the text box disappears 90 days after you enable uniform bucket-level access.

5. In the pop-up menu that appears, select Uniform or Fine-grained.

6. Click Save.

To learn how to get detailed error information about failed Cloud Storage operations in the Google Cloud console, see Troubleshooting.

gsutil

Use the uniformbucketlevelaccess set command:

gsutil uniformbucketlevelaccess set STATE gs://BUCKET_NAME

Where:

• STATE is either on or off.

• BUCKET_NAME is the name of the relevant bucket. For example, my-bucket.

If successful, the response looks like:

Enabling uniform bucket-level access for gs://test-bucket/...

Code samples

C++

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

The following sample enables uniform bucket-level access on a bucket:

View on GitHub Feedback

namespace gcs = ::google::cloud::storage;
using ::google::cloud::StatusOr;
[](gcs::Client client, std::string const& bucket_name) {
  gcs::BucketIamConfiguration configuration;
  configuration.uniform_bucket_level_access =
      gcs::UniformBucketLevelAccess{true, {}};
  StatusOr<gcs::BucketMetadata> updated_metadata = client.PatchBucket(
      bucket_name, gcs::BucketMetadataPatchBuilder().SetIamConfiguration(
                       std::move(configuration)));

  if (!updated_metadata) {
    throw std::runtime_error(updated_metadata.status().message());
  }

  std::cout << "Successfully enabled Uniform Bucket Level Access on bucket "
            << updated_metadata->name() << "\n";
}

The following sample disables uniform bucket-level access on a bucket:

View on GitHub Feedback

namespace gcs = ::google::cloud::storage;
using ::google::cloud::StatusOr;
[](gcs::Client client, std::string const& bucket_name) {
  gcs::BucketIamConfiguration configuration;
  configuration.uniform_bucket_level_access =
      gcs::UniformBucketLevelAccess{false, {}};
  StatusOr<gcs::BucketMetadata> updated_metadata = client.PatchBucket(
      bucket_name, gcs::BucketMetadataPatchBuilder().SetIamConfiguration(
                       std::move(configuration)));

  if (!updated_metadata) {
    throw std::runtime_error(updated_metadata.status().message());
  }

  std::cout << "Successfully disabled Uniform Bucket Level Access on bucket "
            << updated_metadata->name() << "\n";
}

C#

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

The following sample enables uniform bucket-level access on a bucket:

View on GitHub Feedback

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

public class EnableUniformBucketLevelAccessSample
{
    public Bucket EnableUniformBucketLevelAccess(string bucketName = "your-unique-bucket-name")
    {
        var storage = StorageClient.Create();
        var bucket = storage.GetBucket(bucketName);
        bucket.IamConfiguration.UniformBucketLevelAccess.Enabled = true;
        bucket = storage.UpdateBucket(bucket);

        Console.WriteLine($"Uniform bucket-level access was enabled for {bucketName}.");
        return bucket;
    }
}

The following sample disables uniform bucket-level access on a bucket:

View on GitHub Feedback

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

public class DisableUniformBucketLevelAccessSample
{
    public Bucket DisableUniformBucketLevelAccess(string bucketName = "your-unique-bucket-name")
    {
        var storage = StorageClient.Create();
        var bucket = storage.GetBucket(bucketName);
        bucket.IamConfiguration.UniformBucketLevelAccess.Enabled = false;
        bucket.IamConfiguration.BucketPolicyOnly.Enabled = false;
        bucket = storage.UpdateBucket(bucket);

        Console.WriteLine($"Uniform bucket-level access was disabled for {bucketName}.");
        return bucket;
    }
}

Go

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

The following sample enables uniform bucket-level access on a bucket:

View on GitHub Feedback

ctx := context.Background()

bucket := c.Bucket(bucketName)
enableUniformBucketLevelAccess := storage.BucketAttrsToUpdate{
	UniformBucketLevelAccess: &storage.UniformBucketLevelAccess{
		Enabled: true,
	},
}
ctx, cancel := context.WithTimeout(ctx, time.Second*10)
defer cancel()
if _, err := bucket.Update(ctx, enableUniformBucketLevelAccess); err != nil {
	return err
}

The following sample disables uniform bucket-level access on a bucket:

View on GitHub Feedback

ctx := context.Background()

bucket := c.Bucket(bucketName)
disableUniformBucketLevelAccess := storage.BucketAttrsToUpdate{
	UniformBucketLevelAccess: &storage.UniformBucketLevelAccess{
		Enabled: false,
	},
}
ctx, cancel := context.WithTimeout(ctx, time.Second*10)
defer cancel()
if _, err := bucket.Update(ctx, disableUniformBucketLevelAccess); err != nil {
	return err
}

Java

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

The following sample enables uniform bucket-level access on a bucket:

View on GitHub Feedback

import com.google.cloud.storage.BucketInfo;
import com.google.cloud.storage.Storage;
import com.google.cloud.storage.StorageException;
import com.google.cloud.storage.StorageOptions;

public class EnableUniformBucketLevelAccess {
  public static void enableUniformBucketLevelAccess(String projectId, String bucketName)
      throws StorageException {
    // The ID of your GCP project
    // String projectId = "your-project-id";

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

    Storage storage = StorageOptions.newBuilder().setProjectId(projectId).build().getService();
    BucketInfo.IamConfiguration iamConfiguration =
        BucketInfo.IamConfiguration.newBuilder().setIsUniformBucketLevelAccessEnabled(true).build();

    storage.update(BucketInfo.newBuilder(bucketName).setIamConfiguration(iamConfiguration).build());

    System.out.println("Uniform bucket-level access was enabled for " + bucketName);
  }
}

The following sample disables uniform bucket-level access on a bucket:

View on GitHub Feedback

import com.google.cloud.storage.BucketInfo;
import com.google.cloud.storage.Storage;
import com.google.cloud.storage.StorageException;
import com.google.cloud.storage.StorageOptions;

public class DisableUniformBucketLevelAccess {
  public static void disableUniformBucketLevelAccess(String projectId, String bucketName)
      throws StorageException {
    // The ID of your GCP project
    // String projectId = "your-project-id";

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

    Storage storage = StorageOptions.newBuilder().setProjectId(projectId).build().getService();
    BucketInfo.IamConfiguration iamConfiguration =
        BucketInfo.IamConfiguration.newBuilder()
            .setIsUniformBucketLevelAccessEnabled(false)
            .build();

    storage.update(BucketInfo.newBuilder(bucketName).setIamConfiguration(iamConfiguration).build());

    System.out.println("Uniform bucket-level access was disabled for " + bucketName);
  }
}

Node.js

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

The following sample enables uniform bucket-level access on a bucket:

View on GitHub Feedback

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

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

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

// Enables uniform bucket-level access for the bucket
async function enableUniformBucketLevelAccess() {
  await storage.bucket(bucketName).setMetadata({
    iamConfiguration: {
      uniformBucketLevelAccess: {
        enabled: true,
      },
    },
  });

  console.log(`Uniform bucket-level access was enabled for ${bucketName}.`);
}

enableUniformBucketLevelAccess().catch(console.error);

The following sample disables uniform bucket-level access on a bucket:

View on GitHub Feedback

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

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

// Creates a client
const storage = new Storage();
async function disableUniformBucketLevelAccess() {
  // Disables uniform bucket-level access for the bucket
  await storage.bucket(bucketName).setMetadata({
    iamConfiguration: {
      uniformBucketLevelAccess: {
        enabled: false,
      },
    },
  });

  console.log(`Uniform bucket-level access was disabled for ${bucketName}.`);
}

disableUniformBucketLevelAccess().catch(console.error);

PHP

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

The following sample enables uniform bucket-level access on a bucket:

View on GitHub Feedback

use Google\Cloud\Storage\StorageClient;

/**
 * Enable uniform bucket-level access.
 *
 * @param string $bucketName The name of your Cloud Storage bucket.
 */
function enable_uniform_bucket_level_access($bucketName)
{
    // $bucketName = 'my-bucket';

    $storage = new StorageClient();
    $bucket = $storage->bucket($bucketName);
    $bucket->update([
        'iamConfiguration' => [
            'uniformBucketLevelAccess' => [
                'enabled' => true
            ],
        ]
    ]);
    printf('Uniform bucket-level access was enabled for %s' . PHP_EOL, $bucketName);
}

The following sample disables uniform bucket-level access on a bucket:

View on GitHub Feedback

use Google\Cloud\Storage\StorageClient;

/**
 * Enable uniform bucket-level access.
 *
 * @param string $bucketName The name of your Cloud Storage bucket.
 */
function disable_uniform_bucket_level_access($bucketName)
{
    // $bucketName = 'my-bucket';

    $storage = new StorageClient();
    $bucket = $storage->bucket($bucketName);
    $bucket->update([
        'iamConfiguration' => [
            'uniformBucketLevelAccess' => [
                'enabled' => false
            ],
        ]
    ]);
    printf('Uniform bucket-level access was disabled for %s' . PHP_EOL, $bucketName);
}

Python

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

The following sample enables uniform bucket-level access on a bucket:

View on GitHub Feedback

from google.cloud import storage


def enable_uniform_bucket_level_access(bucket_name):
    """Enable uniform bucket-level access for a bucket"""
    # bucket_name = "my-bucket"

    storage_client = storage.Client()
    bucket = storage_client.get_bucket(bucket_name)

    bucket.iam_configuration.uniform_bucket_level_access_enabled = True
    bucket.patch()

    print(
        f"Uniform bucket-level access was enabled for {bucket.name}."
    )

The following sample disables uniform bucket-level access on a bucket:

View on GitHub Feedback

from google.cloud import storage


def disable_uniform_bucket_level_access(bucket_name):
    """Disable uniform bucket-level access for a bucket"""
    # bucket_name = "my-bucket"

    storage_client = storage.Client()
    bucket = storage_client.get_bucket(bucket_name)

    bucket.iam_configuration.uniform_bucket_level_access_enabled = False
    bucket.patch()

    print(
        f"Uniform bucket-level access was disabled for {bucket.name}."
    )

Ruby

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

The following sample enables uniform bucket-level access on a bucket:

View on GitHub Feedback

def enable_uniform_bucket_level_access bucket_name:
  # The ID of your GCS bucket
  # bucket_name = "your-unique-bucket-name"

  require "google/cloud/storage"

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

  bucket.uniform_bucket_level_access = true

  puts "Uniform bucket-level access was enabled for #{bucket_name}."
end

The following sample disables uniform bucket-level access on a bucket:

View on GitHub Feedback

def disable_uniform_bucket_level_access bucket_name:
  # The ID of your GCS bucket
  # bucket_name = "your-unique-bucket-name"

  require "google/cloud/storage"

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

  bucket.uniform_bucket_level_access = false

  puts "Uniform bucket-level access was disabled for #{bucket_name}."
end

REST APIs

JSON API

1. Get an authorization access token from the OAuth 2.0 Playground. Configure the playground to use your own OAuth credentials. For instructions, see API authentication.

2. Create a JSON file that contains the following information:

   {
     "iamConfiguration": {
         "uniformBucketLevelAccess": {
           "enabled": STATE
         }
     }
   }

   Where STATE is either true or false.

3. Use cURL to call the JSON API with a PATCH Bucket request:

   curl -X PATCH --data-binary @JSON_FILE_NAME \
   -H "Authorization: Bearer OAUTH2_TOKEN" \
   -H "Content-Type: application/json" \
   "https://storage.googleapis.com/storage/v1/b/BUCKET_NAME?fields=iamConfiguration"

   Where:

   • JSON_FILE_NAME is the path for the file that you created in Step 2.
   • OAUTH2_TOKEN is the access token you generated in Step 1.
   • BUCKET_NAME is the name of the relevant bucket. For example, my-bucket.

XML API

The XML API cannot be used to work with uniform bucket-level access. Use one of the other Cloud Storage tools, such as gsutil, instead.

View uniform bucket-level access status

Console

1. In the Google Cloud console, go to the Cloud Storage Buckets page.
   

   Go to Buckets

2. In the Column display options menu (), make sure Access control is checked.

3. In the list of buckets, the uniform bucket-level access status of each bucket is found in the Access control column.

To learn how to get detailed error information about failed Cloud Storage operations in the Google Cloud console, see Troubleshooting.

gsutil

Use the uniformbucketlevelaccess get command:

gsutil uniformbucketlevelaccess get gs://BUCKET_NAME

where BUCKET_NAME is the name of the relevant bucket. For example, my-bucket.

If uniform bucket-level access is enabled, the response looks like:

Uniform bucket-level access setting for gs://my-bucket/:
    Enabled: True
    LockedTime: LOCK_DATE 

Code samples

C++

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

View on GitHub Feedback

namespace gcs = ::google::cloud::storage;
using ::google::cloud::StatusOr;
[](gcs::Client client, std::string const& bucket_name) {
  StatusOr<gcs::BucketMetadata> bucket_metadata =
      client.GetBucketMetadata(bucket_name);

  if (!bucket_metadata) {
    throw std::runtime_error(bucket_metadata.status().message());
  }

  if (bucket_metadata->has_iam_configuration() &&
      bucket_metadata->iam_configuration()
          .uniform_bucket_level_access.has_value()) {
    gcs::UniformBucketLevelAccess uniform_bucket_level_access =
        *bucket_metadata->iam_configuration().uniform_bucket_level_access;

    std::cout << "Uniform Bucket Level Access is enabled for "
              << bucket_metadata->name() << "\n";
    std::cout << "Bucket will be locked on " << uniform_bucket_level_access
              << "\n";
  } else {
    std::cout << "Uniform Bucket Level Access is not enabled for "
              << bucket_metadata->name() << "\n";
  }
}

C#

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

View on GitHub Feedback

using Google.Cloud.Storage.V1;
using System;
using static Google.Apis.Storage.v1.Data.Bucket.IamConfigurationData;

public class GetUniformBucketLevelAccessSample
{
    public UniformBucketLevelAccessData GetUniformBucketLevelAccess(
        string bucketName = "your-unique-bucket-name")
    {
        var storage = StorageClient.Create();
        var bucket = storage.GetBucket(bucketName);
        var uniformBucketLevelAccess = bucket.IamConfiguration.UniformBucketLevelAccess;

        bool uniformBucketLevelAccessEnabled = uniformBucketLevelAccess.Enabled ?? false;
        if (uniformBucketLevelAccessEnabled)
        {
            Console.WriteLine($"Uniform bucket-level access is enabled for {bucketName}.");
            Console.WriteLine(
                $"Uniform bucket-level access will be locked on {uniformBucketLevelAccess.LockedTime}.");
        }
        else
        {
            Console.WriteLine($"Uniform bucket-level access is not enabled for {bucketName}.");
        }
        return uniformBucketLevelAccess;
    }
}

Go

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

View on GitHub Feedback

ctx := context.Background()

ctx, cancel := context.WithTimeout(ctx, time.Second*10)
defer cancel()
attrs, err := c.Bucket(bucketName).Attrs(ctx)
if err != nil {
	return nil, err
}
uniformBucketLevelAccess := attrs.UniformBucketLevelAccess
if uniformBucketLevelAccess.Enabled {
	log.Printf("Uniform bucket-level access is enabled for %q.\n",
		attrs.Name)
	log.Printf("Bucket will be locked on %q.\n",
		uniformBucketLevelAccess.LockedTime)
} else {
	log.Printf("Uniform bucket-level access is not enabled for %q.\n",
		attrs.Name)
}

Java

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

View on GitHub Feedback

import com.google.cloud.storage.Bucket;
import com.google.cloud.storage.BucketInfo;
import com.google.cloud.storage.Storage;
import com.google.cloud.storage.StorageException;
import com.google.cloud.storage.StorageOptions;
import java.util.Date;

public class GetUniformBucketLevelAccess {
  public static void getUniformBucketLevelAccess(String projectId, String bucketName)
      throws StorageException {
    // The ID of your GCP project
    // String projectId = "your-project-id";

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

    Storage storage = StorageOptions.newBuilder().setProjectId(projectId).build().getService();
    Bucket bucket =
        storage.get(
            bucketName, Storage.BucketGetOption.fields(Storage.BucketField.IAMCONFIGURATION));
    BucketInfo.IamConfiguration iamConfiguration = bucket.getIamConfiguration();

    Boolean enabled = iamConfiguration.isUniformBucketLevelAccessEnabled();
    Date lockedTime = new Date(iamConfiguration.getUniformBucketLevelAccessLockedTime());

    if (enabled != null && enabled) {
      System.out.println("Uniform bucket-level access is enabled for " + bucketName);
      System.out.println("Bucket will be locked on " + lockedTime);
    } else {
      System.out.println("Uniform bucket-level access is disabled for " + bucketName);
    }
  }
}

Node.js

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

View on GitHub Feedback

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

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

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

async function getUniformBucketLevelAccess() {
  // Gets Bucket Metadata and checks if uniform bucket-level access is enabled.
  const [metadata] = await storage.bucket(bucketName).getMetadata();

  if (metadata.iamConfiguration) {
    const uniformBucketLevelAccess =
      metadata.iamConfiguration.uniformBucketLevelAccess;
    console.log(`Uniform bucket-level access is enabled for ${bucketName}.`);
    console.log(
      `Bucket will be locked on ${uniformBucketLevelAccess.lockedTime}.`
    );
  } else {
    console.log(
      `Uniform bucket-level access is not enabled for ${bucketName}.`
    );
  }
}

getUniformBucketLevelAccess().catch(console.error);

PHP

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

View on GitHub Feedback

use Google\Cloud\Storage\StorageClient;

/**
 * Enable uniform bucket-level access.
 *
 * @param string $bucketName The name of your Cloud Storage bucket.
 */
function get_uniform_bucket_level_access($bucketName)
{
    // $bucketName = 'my-bucket';

    $storage = new StorageClient();
    $bucket = $storage->bucket($bucketName);
    $bucketInformation = $bucket->info();
    $ubla = $bucketInformation['iamConfiguration']['uniformBucketLevelAccess'];
    if ($ubla['enabled']) {
        printf('Uniform bucket-level access is enabled for %s' . PHP_EOL, $bucketName);
        printf('Uniform bucket-level access will be locked on %s' . PHP_EOL, $ubla['LockedTime']);
    } else {
        printf('Uniform bucket-level access is disabled for %s' . PHP_EOL, $bucketName);
    }
}

Python

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

View on GitHub Feedback

from google.cloud import storage


def get_uniform_bucket_level_access(bucket_name):
    """Get uniform bucket-level access for a bucket"""
    # bucket_name = "my-bucket"

    storage_client = storage.Client()
    bucket = storage_client.get_bucket(bucket_name)
    iam_configuration = bucket.iam_configuration

    if iam_configuration.uniform_bucket_level_access_enabled:
        print(
            f"Uniform bucket-level access is enabled for {bucket.name}."
        )
        print(
            "Bucket will be locked on {}.".format(
                iam_configuration.uniform_bucket_level_locked_time
            )
        )
    else:
        print(
            f"Uniform bucket-level access is disabled for {bucket.name}."
        )

Ruby

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

View on GitHub Feedback

def get_uniform_bucket_level_access bucket_name:
  # The ID of your GCS bucket
  # bucket_name = "your-unique-bucket-name"

  require "google/cloud/storage"

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

  if bucket.uniform_bucket_level_access?
    puts "Uniform bucket-level access is enabled for #{bucket_name}."
    puts "Bucket will be locked on #{bucket.uniform_bucket_level_access_locked_at}."
  else
    puts "Uniform bucket-level access is disabled for #{bucket_name}."
  end
end

REST APIs

JSON API

1. Get an authorization access token from the OAuth 2.0 Playground. Configure the playground to use your own OAuth credentials. For instructions, see API authentication.

2. Use cURL to call the JSON API with a GET Bucket request that includes the desired fields:

   curl -X GET -H "Authorization: Bearer OAUTH2_TOKEN" \
   "https://storage.googleapis.com/storage/v1/b/BUCKET_NAME?fields=iamConfiguration"

   Where:

   • OAUTH2_TOKEN is the access token you generated in Step 1.
   • BUCKET_NAME is the name of the relevant bucket. For example, my-bucket.

   If the bucket has uniform bucket-level access enabled, the response looks like the following example:

   {
     "iamConfiguration": {
         "uniformBucketLevelAccess": {
           "enabled": true,
           "lockedTime": "LOCK_DATE"
         }
       }
     }

XML API

The XML API cannot be used to work with uniform bucket-level access. Use one of the other Cloud Storage tools, such as gsutil, instead.

What's next

• Learn more about uniform bucket-level access.
• Set IAM permissions on buckets and projects.