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 client libraries.

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 client libraries.

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 client libraries.

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 client libraries.

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 client libraries.

/**
 * 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 client libraries.

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 client libraries.

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 client libraries.

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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