Object Storage Service:Copy objects (SDK for Go V2)

Precautions

• The sample code in this topic uses the China (Hangzhou) region ID cn-hangzhou and a public endpoint by default. If you want to access OSS from another Alibaba Cloud service in the same region, use an internal endpoint instead. For the mapping between OSS regions and endpoints, see Regions and endpoints.

• This topic uses environment variables as an example to read access credentials. For information about how to configure access credentials, see Configure access credentials.

• Read permission on the source object and read and write permissions on the destination bucket are required to copy an object.

• Cross-region copy is not supported. For example, you cannot copy an object from a bucket in the China (Hangzhou) region to a bucket in the China (Qingdao) region.

• When you copy an object, make sure that neither the source bucket nor the destination bucket has a retention policy configured. Otherwise, the operation fails and returns the error: The object you specified is immutable.

Permissions

By default, an Alibaba Cloud account has full permissions. RAM users or RAM roles under an Alibaba Cloud account do not have any permissions by default. The Alibaba Cloud account or account administrator must grant operation permissions through RAM policies or Bucket Policy.

Method signature

func (c *Client) CopyObject(ctx context.Context, request *CopyObjectRequest, optFns ...func(*Options)) (*CopyObjectResult, error)

Request parameters

The following table describes the common parameters of CopyObjectRequest:

Response parameters

Sample code

Use the following sample code to copy an object smaller than 5 GiB from a source bucket to a destination bucket.

package main

import (
	"context"
	"flag"
	"log"

	"github.com/aliyun/alibabacloud-oss-go-sdk-v2/oss"
	"github.com/aliyun/alibabacloud-oss-go-sdk-v2/oss/credentials"
)

// Specify the global variables.
var (
	region         string // The region in which the bucket is located.
	srcBucketName  string // The name of the source bucket.
	srcObjectName  string // The name of the source object.
	destBucketName string // The name of the destination bucket.
	destObjectName string // The name of the destination object.
)

// Specify the init function used to initialize command line parameters.
func init() {
	flag.StringVar(&region, "region", "", "The region in which the bucket is located.")
	flag.StringVar(&srcBucketName, "src-bucket", "", "The name of the source bucket.")
	flag.StringVar(&srcObjectName, "src-object", "", "The name of the source object.")
	flag.StringVar(&destBucketName, "dest-bucket", "", "The name of the destination bucket.")
	flag.StringVar(&destObjectName, "dest-object", "", "The name of the destination object.")
}

func main() {
	// Parse the command line parameters.
	flag.Parse()

	// Check whether the source bucket name is empty.
	if len(srcBucketName) == 0 {
		flag.PrintDefaults()
		log.Fatalf("invalid parameters, source bucket name required")
	}

	// Check whether the region is empty.
	if len(region) == 0 {
		flag.PrintDefaults()
		log.Fatalf("invalid parameters, region required")
	}

	// If the destination bucket name is not specified, use the source bucket name.
	if len(destBucketName) == 0 {
		destBucketName = srcBucketName
	}

	// Check whether the source object name is empty.
	if len(srcObjectName) == 0 {
		flag.PrintDefaults()
		log.Fatalf("invalid parameters, source object name required")
	}

	// Check whether the destination object name is empty.
	if len(destObjectName) == 0 {
		flag.PrintDefaults()
		log.Fatalf("invalid parameters, destination object name required")
	}

	// Load the default configuration and specify the credential provider and region.
	cfg := oss.LoadDefaultConfig().
		WithCredentialsProvider(credentials.NewEnvironmentVariableCredentialsProvider()).
		WithRegion(region)

	// Create an OSS client.
	client := oss.NewClient(cfg)

	// Create a request for copying the object.
	request := &oss.CopyObjectRequest{
		Bucket:       oss.Ptr(destBucketName), // The name of the destination bucket.
		Key:          oss.Ptr(destObjectName), // The name of the destination object.
		SourceKey:    oss.Ptr(srcObjectName),  // The name of the source object.
		SourceBucket: oss.Ptr(srcBucketName),  // The name of the source bucket.
	}

	// Perform the copy object operation and handle the result.
	result, err := client.CopyObject(context.TODO(), request)
	if err != nil {
		log.Fatalf("failed to copy object %v", err)
	}
	log.Printf("copy object result:%#v\n", result)
}

References

• For the complete sample code for copying objects, see GitHub sample.

• For the API operation used to copy objects, see CopyObject.