Copy an object between buckets

Copy an object from one Cloud Storage bucket to another.

Explore further

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

• Copy, rename, and move objects

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& source_bucket_name,
   std::string const& source_object_name,
   std::string const& destination_bucket_name,
   std::string const& destination_object_name) {
  StatusOr<gcs::ObjectMetadata> new_copy_meta =
      client.CopyObject(source_bucket_name, source_object_name,
                        destination_bucket_name, destination_object_name);
  if (!new_copy_meta) throw std::move(new_copy_meta).status();

  std::cout << "Successfully copied " << source_object_name << " in bucket "
            << source_bucket_name << " to bucket " << new_copy_meta->bucket()
            << " with name " << new_copy_meta->name()
            << ".\nThe full metadata after the copy is: " << *new_copy_meta
            << "\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.Cloud.Storage.V1;
using System;

public class CopyFileSample
{
    public void CopyFile(
        string sourceBucketName = "source-bucket-name",
        string sourceObjectName = "source-file",
        string destBucketName = "destination-bucket-name",
        string destObjectName = "destination-file-name")
    {
        var storage = StorageClient.Create();
        storage.CopyObject(sourceBucketName, sourceObjectName, destBucketName, destObjectName);

        Console.WriteLine($"Copied {sourceBucketName}/{sourceObjectName} to " + $"{destBucketName}/{destObjectName}.");
    }
}

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"
	"time"

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

// copyFile copies an object into specified bucket.
func copyFile(w io.Writer, dstBucket, srcBucket, srcObject string) error {
	// dstBucket := "bucket-1"
	// srcBucket := "bucket-2"
	// srcObject := "object"
	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*10)
	defer cancel()

	dstObject := srcObject + "-copy"
	src := client.Bucket(srcBucket).Object(srcObject)
	dst := client.Bucket(dstBucket).Object(dstObject)

	// Optional: set a generation-match precondition to avoid potential race
	// conditions and data corruptions. The request to copy is aborted if the
	// object's generation number does not match your precondition.
	// For a dst object that does not yet exist, set the DoesNotExist precondition.
	dst = dst.If(storage.Conditions{DoesNotExist: true})
	// If the destination object already exists in your bucket, set instead a
	// generation-match precondition using its generation number.
	// attrs, err := dst.Attrs(ctx)
	// if err != nil {
	// 	return fmt.Errorf("object.Attrs: %w", err)
	// }
	// dst = dst.If(storage.Conditions{GenerationMatch: attrs.Generation})

	if _, err := dst.CopierFrom(src).Run(ctx); err != nil {
		return fmt.Errorf("Object(%q).CopierFrom(%q).Run: %w", dstObject, srcObject, err)
	}
	fmt.Fprintf(w, "Blob %v in bucket %v copied to blob %v in bucket %v.\n", srcObject, srcBucket, dstObject, dstBucket)
	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.BlobId;
import com.google.cloud.storage.Storage;
import com.google.cloud.storage.StorageOptions;

public class CopyObject {
  public static void copyObject(
      String projectId, String sourceBucketName, String objectName, String targetBucketName) {
    // The ID of your GCP project
    // String projectId = "your-project-id";

    // The ID of the bucket the original object is in
    // String sourceBucketName = "your-source-bucket";

    // The ID of the GCS object to copy
    // String objectName = "your-object-name";

    // The ID of the bucket to copy the object to
    // String targetBucketName = "target-object-bucket";

    Storage storage = StorageOptions.newBuilder().setProjectId(projectId).build().getService();
    BlobId source = BlobId.of(sourceBucketName, objectName);
    BlobId target =
        BlobId.of(
            targetBucketName, objectName); // you could change "objectName" to rename the object

    // Optional: set a generation-match precondition to avoid potential race
    // conditions and data corruptions. The request returns a 412 error if the
    // preconditions are not met.
    Storage.BlobTargetOption precondition;
    if (storage.get(targetBucketName, objectName) == null) {
      // For a target object that does not yet exist, set the DoesNotExist precondition.
      // This will cause the request to fail if the object is created before the request runs.
      precondition = Storage.BlobTargetOption.doesNotExist();

    } else {
      // If the destination already exists in your bucket, instead set a generation-match
      // precondition. This will cause the request to fail if the existing object's generation
      // changes before the request runs.
      precondition =
          Storage.BlobTargetOption.generationMatch(
              storage.get(targetBucketName, objectName).getGeneration());
    }

    storage.copy(
        Storage.CopyRequest.newBuilder().setSource(source).setTarget(target, precondition).build());

    System.out.println(
        "Copied object "
            + objectName
            + " from bucket "
            + sourceBucketName
            + " to "
            + targetBucketName);
  }
}

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 the bucket the original file is in
// const srcBucketName = 'your-source-bucket';

// The ID of the GCS file to copy
// const srcFilename = 'your-file-name';

// The ID of the bucket to copy the file to
// const destBucketName = 'target-file-bucket';

// The ID of the GCS file to create
// const destFileName = 'target-file-name';

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

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

async function copyFile() {
  const copyDestination = storage.bucket(destBucketName).file(destFileName);

  // Optional:
  // Set a generation-match precondition to avoid potential race conditions
  // and data corruptions. The request to copy is aborted if the object's
  // generation number does not match your precondition. For a destination
  // object that does not yet exist, set the ifGenerationMatch precondition to 0
  // If the destination object already exists in your bucket, set instead a
  // generation-match precondition using its generation number.
  const copyOptions = {
    preconditionOpts: {
      ifGenerationMatch: destinationGenerationMatchPrecondition,
    },
  };

  // Copies the file to the other bucket
  await storage
    .bucket(srcBucketName)
    .file(srcFilename)
    .copy(copyDestination, copyOptions);

  console.log(
    `gs://${srcBucketName}/${srcFilename} copied to gs://${destBucketName}/${destFileName}`
  );
}

copyFile().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;

/**
 * Copy an object to a new name and/or bucket.
 *
 * @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 $newBucketName The destination bucket name.
 *        (e.g. 'my-other-bucket')
 * @param string $newObjectName The destination object name.
 *        (e.g. 'my-other-object')
 */
function copy_object(string $bucketName, string $objectName, string $newBucketName, string $newObjectName): void
{
    $storage = new StorageClient();
    $bucket = $storage->bucket($bucketName);
    $object = $bucket->object($objectName);
    $object->copy($newBucketName, ['name' => $newObjectName]);
    printf('Copied gs://%s/%s to gs://%s/%s' . PHP_EOL,
        $bucketName, $objectName, $newBucketName, $newObjectName);
}

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 copy_blob(
    bucket_name, blob_name, destination_bucket_name, destination_blob_name,
):
    """Copies a blob from one bucket to another with a new name."""
    # bucket_name = "your-bucket-name"
    # blob_name = "your-object-name"
    # destination_bucket_name = "destination-bucket-name"
    # destination_blob_name = "destination-object-name"

    storage_client = storage.Client()

    source_bucket = storage_client.bucket(bucket_name)
    source_blob = source_bucket.blob(blob_name)
    destination_bucket = storage_client.bucket(destination_bucket_name)

    # Optional: set a generation-match precondition to avoid potential race conditions
    # and data corruptions. The request to copy is aborted if the object's
    # generation number does not match your precondition. For a destination
    # object that does not yet exist, set the if_generation_match precondition to 0.
    # If the destination object already exists in your bucket, set instead a
    # generation-match precondition using its generation number.
    # There is also an `if_source_generation_match` parameter, which is not used in this example.
    destination_generation_match_precondition = 0

    blob_copy = source_bucket.copy_blob(
        source_blob, destination_bucket, destination_blob_name, if_generation_match=destination_generation_match_precondition,
    )

    print(
        "Blob {} in bucket {} copied to blob {} in bucket {}.".format(
            source_blob.name,
            source_bucket.name,
            blob_copy.name,
            destination_bucket.name,
        )
    )

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.

def copy_file source_bucket_name:, source_file_name:, destination_bucket_name:, destination_file_name:
  # The ID of the bucket the original object is in
  # source_bucket_name = "source-bucket-name"

  # The ID of the GCS object to copy
  # source_file_name = "source-file-name"

  # The ID of the bucket to copy the object to
  # destination_bucket_name = "destination-bucket-name"

  # The ID of the new GCS object
  # destination_file_name = "destination-file-name"

  require "google/cloud/storage"

  storage = Google::Cloud::Storage.new
  bucket  = storage.bucket source_bucket_name, skip_lookup: true
  file    = bucket.file source_file_name

  destination_bucket = storage.bucket destination_bucket_name
  destination_file   = file.copy destination_bucket.name, destination_file_name

  puts "#{file.name} in #{bucket.name} copied to " \
       "#{destination_file.name} in #{destination_bucket.name}"
end

What's next

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