Lock a bucket's retention policy

Provides an example of how to lock a bucket's retention policy.

Explore further

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

• Use and lock retention policies

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) {
  StatusOr<gcs::BucketMetadata> original =
      client.GetBucketMetadata(bucket_name);
  if (!original) throw std::move(original).status();

  StatusOr<gcs::BucketMetadata> updated_metadata =
      client.LockBucketRetentionPolicy(bucket_name,
                                       original->metageneration());
  if (!updated_metadata) throw std::move(updated_metadata).status();

  if (!updated_metadata->has_retention_policy()) {
    std::cerr << "The bucket " << updated_metadata->name()
              << " does not have a retention policy, even though the"
              << " operation to set it was successful.\n"
              << "This is unexpected, and may indicate that another"
              << " application has modified the bucket concurrently.\n";
    return;
  }

  std::cout << "Retention policy successfully locked for bucket "
            << updated_metadata->name() << "\nNew retention policy is: "
            << updated_metadata->retention_policy()
            << "\nFull metadata: " << *updated_metadata << "\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.Cloud.Storage.V1;
using System;

public class LockRetentionPolicySample
{
    /// <summary>
    /// Locks the retention policy of a bucket. This is a one-way process: once a retention
    /// policy is locked, it cannot be shortened, removed or unlocked, although it can
    /// be increased in duration. The lock persists until the bucket is deleted.
    /// </summary>
    /// <param name="bucketName">The name of the bucket whose retention policy should be locked.</param>
    public bool? LockRetentionPolicy(string bucketName = "your-unique-bucket-name")
    {
        var storage = StorageClient.Create();
        var bucket = storage.GetBucket(bucketName);
        storage.LockBucketRetentionPolicy(bucketName, bucket.Metageneration.Value);
        bucket = storage.GetBucket(bucketName);
        Console.WriteLine($"Retention policy for {bucketName} is now locked");
        Console.WriteLine($"Retention policy effective as of {bucket.RetentionPolicy.EffectiveTime}");

        return bucket.RetentionPolicy.IsLocked;
    }
}

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"
	"time"

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

// lockRetentionPolicy locks bucket retention policy.
func lockRetentionPolicy(w io.Writer, bucketName string) error {
	// bucketName := "bucket-name"
	ctx := context.Background()
	client, err := storage.NewClient(ctx)
	if err != nil {
		return fmt.Errorf("storage.NewClient: %w", err)
	}
	defer client.Close()

	ctx, cancel := context.WithTimeout(ctx, time.Second*50)
	defer cancel()

	bucket := client.Bucket(bucketName)
	attrs, err := bucket.Attrs(ctx)
	if err != nil {
		return fmt.Errorf("Bucket(%q).Attrs: %w", bucketName, err)
	}

	conditions := storage.BucketConditions{
		MetagenerationMatch: attrs.MetaGeneration,
	}
	if err := bucket.If(conditions).LockRetentionPolicy(ctx); err != nil {
		return fmt.Errorf("Bucket(%q).LockRetentionPolicy: %w", bucketName, err)
	}

	lockedAttrs, err := bucket.Attrs(ctx)
	if err != nil {
		return fmt.Errorf("Bucket(%q).Attrs: lockedAttrs: %w", bucketName, err)
	}

	fmt.Fprintf(w, "Retention policy for %v is now locked\n", bucketName)
	fmt.Fprintf(w, "Retention policy effective as of %v\n", lockedAttrs.RetentionPolicy.EffectiveTime)
	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.Bucket;
import com.google.cloud.storage.Storage;
import com.google.cloud.storage.StorageException;
import com.google.cloud.storage.StorageOptions;
import java.util.Date;

public class LockRetentionPolicy {
  public static void lockRetentionPolicy(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.METAGENERATION));
    Bucket lockedBucket =
        bucket.lockRetentionPolicy(Storage.BucketTargetOption.metagenerationMatch());

    System.out.println("Retention period for " + bucketName + " is now locked");
    System.out.println(
        "Retention policy effective as of " + new Date(lockedBucket.getRetentionEffectiveTime()));
  }
}

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';

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

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

async function lockRetentionPolicy() {
  // Gets the current metageneration value for the bucket, required by
  // lock_retention_policy
  const [unlockedMetadata] = await storage.bucket(bucketName).getMetadata();

  // Warning: Once a retention policy is locked, it cannot be unlocked. The
  // retention period can only be increased
  const [lockedMetadata] = await storage
    .bucket(bucketName)
    .lock(unlockedMetadata.metageneration);
  console.log(`Retention policy for ${bucketName} is now locked`);
  console.log(
    `Retention policy effective as of ${lockedMetadata.retentionPolicy.effectiveTime}`
  );

  return lockedMetadata;
}

lockRetentionPolicy().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;

/**
 * Locks a bucket's retention policy.
 *
 * @param string $bucketName The name of your Cloud Storage bucket.
 *        (e.g. 'my-bucket')
 */
function lock_retention_policy(string $bucketName): void
{
    $storage = new StorageClient();
    $bucket = $storage->bucket($bucketName);
    $bucket->reload();
    $bucket->lockRetentionPolicy();
    printf('Bucket %s retention policy locked' . PHP_EOL, $bucketName);
}

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 lock_retention_policy(bucket_name):
    """Locks the retention policy on a given bucket"""
    # bucket_name = "my-bucket"

    storage_client = storage.Client()
    # get_bucket gets the current metageneration value for the bucket,
    # required by lock_retention_policy.
    bucket = storage_client.get_bucket(bucket_name)

    # Warning: Once a retention policy is locked it cannot be unlocked
    # and retention period can only be increased.
    bucket.lock_retention_policy()

    print(f"Retention policy for {bucket_name} is now locked")
    print(
        f"Retention policy effective as of {bucket.retention_policy_effective_time}"
    )

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.

def lock_retention_policy 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

  # Warning: Once a retention policy is locked it cannot be unlocked
  # and retention period can only be increased.
  # Uses Bucket#metageneration as a precondition.
  bucket.lock_retention_policy!

  puts "Retention policy for #{bucket_name} is now locked."
  puts "Retention policy effective as of #{bucket.retention_effective_at}."
end

What's next

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