Copying an Object (SDK for Go)_Object Storage Service

Function

This API copies an object stored in OBS to another path. You can create a backup up to 5 GB for an object in a specified bucket by a single operation.

Restrictions

To copy an object, you must be the bucket owner or have the required permission (obs:object:PutObject in IAM or PutObject in a bucket policy). For details, see Introduction to OBS Access Control, IAM Custom Policies, and Configuring an Object Policy.
The object copy request carries the information about the bucket and object to be copied in the header field. The message body cannot be carried.
The target object size ranges from 0 to 5 GB. If the source object size exceeds 5 GB, you can only copy some objects using Multipart Uploads (SDK for Go).

Method

func (obsClient ObsClient) CopyObject(input *CopyObjectInput) (output *CopyObjectOutput, err error)

Request Parameters

**Table 1** List of request parameters
Parameter	Type	Mandatory (Yes/No)	Description
input	*CopyObjectInput	Yes	Explanation: Input parameters for copying an object. For details, see Table 2.

**Table 2** CopyObjectInput
Parameter	Type	Mandatory (Yes/No)	Description
Bucket	string	Yes	Explanation: Bucket name Restrictions: A bucket name must be unique across all accounts and regions. A bucket name: Must be 3 to 63 characters long and start with a digit or letter. Lowercase letters, digits, hyphens (-), and periods (.) are allowed. Cannot be formatted as an IP address. Cannot start or end with a hyphen (-) or period (.). Cannot contain two consecutive periods (..), for example, my..bucket. Cannot contain a period (.) and a hyphen (-) adjacent to each other, for example, my-.bucket or my.-bucket. If you repeatedly create buckets of the same name in the same region, no error will be reported and the bucket attributes comply with those set in the first creation request. Default value: None
Key	string	Yes	Explanation: Target object name An object is uniquely identified by an object name in a bucket. An object name is a complete path that does not contain the bucket name. For example, if the address for accessing the object is examplebucket.obs.eu-west-101.myhuaweicloud.com/folder/test.txt, the object name is folder/test.txt. Value range: The value must contain 1 to 1,024 characters. Default value: None
CopySourceBucket	string	Yes	Explanation: Source bucket name Restrictions: A bucket name must be unique across all accounts and regions. A bucket name: Must be 3 to 63 characters long and start with a digit or letter. Lowercase letters, digits, hyphens (-), and periods (.) are allowed. Cannot be formatted as an IP address. Cannot start or end with a hyphen (-) or period (.). Cannot contain two consecutive periods (..), for example, my..bucket. Cannot contain a period (.) and a hyphen (-) adjacent to each other, for example, my-.bucket or my.-bucket. If you repeatedly create buckets of the same name in the same region, no error will be reported and the bucket attributes comply with those set in the first creation request. Default value: None
CopySourceKey	string	Yes	Explanation: Source object name An object is uniquely identified by an object name in a bucket. An object name is a complete path that does not contain the bucket name. For example, if the address for accessing the object is examplebucket.obs.eu-west-101.myhuaweicloud.com/folder/test.txt, the object name is folder/test.txt. Value range: The value must contain 1 to 1,024 characters. Default value: None
CopySourceVersionId	string	No	Explanation: Version ID of the source object, for example, G001117FCE89978B0000401205D5DC9A Value range: The value must contain 32 characters. Default value: If this parameter is left blank, the latest version of the source object is copied.
ACL	AclType	No	Explanation: ACL that can be pre-defined during the object copy. For details about the ACL, see ACLs. Value range: See Table 3. Default value: None
MetadataDirective	MetadataDirectiveType	No	Explanation: Policy for copying the source object's properties Value range: See Table 4. Default value: None
CopySourceIfMatch	string	No	Explanation: Copies the source object if its ETag is the same as the one specified by this parameter; otherwise, an error is returned. Default value: None
CopySourceIfNoneMatch	string	No	Explanation: Copies the source object if its ETag is different from the one specified by this parameter; otherwise, an error is returned. Default value: None
CopySourceIfUnmodifiedSince	time.Time	No	Explanation: Copies the source object if it has not been modified since the specified time; otherwise, an exception is thrown. Default value: None
CopySourceIfModifiedSince	time.Time	No	Explanation: Copies the source object if it has been modified since the specified time; otherwise, an exception is thrown. Default value: None
WebsiteRedirectLocation	string	No	Explanation: If the bucket is configured with website hosting, the request for obtaining the object can be redirected to another object in the bucket or an external URL. The request is redirected to object anotherPage.html in the same bucket: WebsiteRedirectLocation:/anotherPage.html The request is redirected to an external URL http://www.example.com/: WebsiteRedirectLocation:http://www.example.com/ OBS obtains the specified value from the header and stores it in the object metadata WebsiteRedirectLocation. Restrictions: The value must start with a slash (/), http://, or https:// and cannot exceed 2 KB. OBS only supports redirection for objects in the root directory of a bucket. Default value: None
SseHeader	SseCHeader or SseKmsHeader	No	Explanation: Server-side header used for encrypting the target object. If SSE-C is used, see SseCHeader. If SSE-KMS is used, see SseKmsHeader.
SourceSseHeader	SseCHeader	No	Explanation: Server-side header used for decrypting the source object. For details, see SseCHeader.
CacheControl	string	No	Explanation: Cache-Control is rewritten in the response. Default value: None
ContentDisposition	string	No	Explanation: Rewrites the Content-Disposition header in the response. Default value: None
ContentEncoding	string	No	Explanation: Rewrites the Content-Encoding header in the response. Default value: None
ContentLanguage	string	No	Explanation: Content-Language is rewritten in the response. Default value: None
ContentType	string	No	Explanation: Content-Type is rewritten in the response. Default value: None
Expires	string	No	Explanation: Expires is rewritten in the response. Default value: None
StorageClass	StorageClassType	No	Explanation: Object storage class Value range: See Table 7. Default value: None. If this parameter is not specified, the storage class of the bucket is used as that of the object.
Metadata	map[string]string	No	Explanation: Custom metadata of the target object. You can add a header starting with x-obs-meta- in the request to define metadata. The custom metadata will be returned in the response when you retrieve the object or query the object metadata. Restrictions: The custom metadata cannot exceed 8 KB. To measure the custom metadata, sum the number of bytes in the UTF-8 encoding of each key and value. The custom metadata keys are case insensitive, but are stored in lowercase in OBS. The key values are case sensitive. Both custom metadata keys and their values must conform to US-ASCII standards. If non-ASCII or unrecognizable characters are necessary, they must be encoded or decoded in URL or Base64 on the client, because the server side does not perform any decoding. Default value: None
GrantReadId	string	No	Explanation: ID (domain_id) of an account the READ permission is granted to. The account with the READ permission can read the object to copy and obtain its metadata. Value range: To obtain the account ID, see How Do I Get My Account ID and User ID? Default value: None
GrantReadAcpId	string	No	Explanation: ID (domain_id) of an account the READ_ACP permission is granted to. The account with the READ_ACP permission can read the ACL of the object to copy. Value range: To obtain the account ID, see How Do I Get My Account ID and User ID? Default value: None
GrantWriteAcpId	string	No	Explanation: ID (domain_id) of an account the WRITE_ACP permission is granted to. The account with the WRITE_ACP permission can write the ACL of the object to copy. Value range: To obtain the account ID, see How Do I Get My Account ID and User ID? Default value: None
GrantFullControlId	string	No	Explanation: ID (domain_id) of an account the FULL_CONTROL permission is granted to. The account with the FULL_CONTROL permission can read the object to copy, obtain its metadata, and obtain and write its ACL. Value range: To obtain the account ID, see How Do I Get My Account ID and User ID? Default value: None
SuccessActionRedirect	string	No	Explanation: Address (URL) to which a successfully answered request is redirected If the value is valid and the request is successful, OBS returns status code 303. Location contains SuccessActionRedirect as well as the bucket name, object name, and object ETag. If the value is invalid, OBS ignores this parameter. In such case, the Location header is the object address, and OBS returns a status code based on whether the operation succeeds or fails. Default value: None

**Table 3** AclType
Constant	Default Value	Description
AclPrivate	private	Private read/write A bucket or object can only be accessed by its owner.
AclPublicRead	public-read	Public read and private write If this permission is granted on a bucket, anyone can read the object list, multipart tasks, metadata, and object versions in the bucket. If it is granted on an object, anyone can read the content and metadata of the object.
AclPublicReadWrite	public-read-write	Public read/write If this permission is granted on a bucket, anyone can read the object list, multipart tasks, metadata, and object versions in the bucket, and can upload or delete objects, initiate multipart upload tasks, upload parts, assemble parts, copy parts, and abort multipart upload tasks. If it is granted on an object, anyone can read the content and metadata of the object.
AclPublicReadDelivered	public-read-delivered	Public read on a bucket as well as objects in the bucket If this permission is granted on a bucket, anyone can read the object list, multipart tasks, metadata, and object versions, and read the content and metadata of objects in the bucket. NOTE: AclPublicReadDelivered does not apply to objects.
AclPublicReadWriteDelivered	public-read-write-delivered	Public read/write on a bucket as well as objects in the bucket If this permission is granted on a bucket, anyone can read the object list, multipart uploads, metadata, and object versions in the bucket, and can upload or delete objects, initiate multipart upload tasks, upload parts, assemble parts, copy parts, and abort multipart uploads. They can also read the content and metadata of objects in the bucket. NOTE: AclPublicReadWriteDelivered does not apply to objects.
AclBucketOwnerFullControl	bucket-owner-full-control	If this permission is granted on an object, only the bucket and object owners have the full control over the object. By default, if you upload an object to a bucket of any other user, the bucket owner does not have the permissions on your object. After you grant this policy to the bucket owner, the bucket owner can have full control over your object.

**Table 4** MetadataDirectiveType
Constant	Default Value	Description
CopyMetadata	COPY	When copying an object, the object's properties are also copied.
ReplaceMetadata	REPLACE	When copying an object, the object's properties are replaced.

**Table 5** SseCHeader
Parameter	Type	Mandatory (Yes/No)	Description
Encryption	string	Yes if used as a request parameter	Explanation: SSE-C used for encrypting objects Value range: AES256, indicating objects are encrypted using SSE-C Default value: None
Key	string	Yes if used as a request parameter	Explanation: Key for encrypting the object when SSE-C is used Restrictions: The value is a Base64-encoded 256-bit key, for example, K7QkYpBkM5+hca27fsNkUnNVaobncnLht/rCB2o/9Cw=. Default value: None
KeyMD5	string	No if used as a request parameter	Explanation: MD5 value of the key for encrypting objects when SSE-C is used. This value is used to check whether any error occurs during the transmission of the key. Restrictions: The value is encrypted by MD5 and then encoded by Base64, for example, 4XvB3tbNTN+tIEVa0/fGaQ==. Default value: None

**Table 6** SseKmsHeader
Parameter	Type	Mandatory (Yes/No)	Description
Encryption	string	Yes if used as a request parameter	Explanation: SSE-KMS used for encrypting objects Value range: kms, indicating objects are encrypted using SSE-KMS Default value: None
Key	string	No if used as a request parameter	Explanation: ID of the KMS master key when SSE-KMS is used Value range: Valid value formats are as follows: regionID:domainID:key/key_id key_id In the preceding formats: regionID indicates the ID of the region where the key is used. domainID indicates the ID of the account where the key is used. To obtain it, see How Do I Get My Account ID and User ID? key_id indicates the ID of the key created on Data Encryption Workshop (DEW). Default value: If this parameter is not specified, the default master key will be used. If there is no such a default master key, OBS will create one and use it by default.

**Table 7** StorageClassType
Constant	Default Value	Description
StorageClassStandard	STANDARD	OBS Standard Features low access latency and high throughput and is used for storing massive, frequently accessed (multiple times a month) or small objects (< 1 MB) requiring quick response.
StorageClassWarm	WARM	OBS Infrequent Access Used for storing data that is semi-frequently accessed (fewer than 12 times a year) but is instantly available when needed.
StorageClassCold	COLD	OBS Archive Used for storing rarely accessed (once a year) data.

Responses

**Table 8** List of returned results
Parameter	Type	Description
output	*CopyObjectOutput	Explanation: Messages returned by the API See Table 9.
err	error	Explanation: Error messages returned by the API

**Table 9** CopyObjectOutput
Parameter	Type	Description
StatusCode	int	Explanation: HTTP status code Value range: A status code is a group of digits that can be 2xx (indicating successes) or 4xx or 5xx (indicating errors). It indicates the status of a response. For more information, see Status Code. Default value: None
RequestId	string	Explanation: Request ID returned by the OBS server Default value: None
ResponseHeaders	map[string][]string	Explanation: HTTP response headers Default value: None
LastModified	time.Time	Explanation: Time when the last modification was made to the target object Value range: UTC time Default value: None
ETag	string	Explanation: ETag of the target object. Base64-encoded, 128-bit MD5 value of an object. ETag is the unique identifier of the object content. It can be used to determine whether the object content is changed. For example, if the ETag value is A when an object is uploaded, but changes to B when the object is downloaded, it indicates that the object content has been changed. The ETag reflects changes to the object content, rather than the object metadata. An uploaded or copied object has a unique ETag after being encrypted using MD5. Restrictions: If an object is encrypted using server-side encryption, the ETag is not the MD5 value of the object. Value range: The value must contain 32 characters. Default value: None
CopySourceVersionId	string	Explanation: Version ID of the source object Value range: The value must contain 32 characters. Default value: None
VersionId	string	Explanation: Version ID of the target object Value range: The value must contain 32 characters. Default value: None
SseHeader	SseCHeader or SseKmsHeader	Explanation: Server-side encryption header information. If SSE-C is used, see Table 10. If SSE-KMS is used, see Table 11.

**Table 10** SseCHeader
Parameter	Type	Mandatory (Yes/No)	Description
Encryption	string	Yes if used as a request parameter	Explanation: SSE-C used for encrypting objects Value range: AES256, indicating objects are encrypted using SSE-C Default value: None
Key	string	Yes if used as a request parameter	Explanation: Key for encrypting the object when SSE-C is used Restrictions: The value is a Base64-encoded 256-bit key, for example, K7QkYpBkM5+hca27fsNkUnNVaobncnLht/rCB2o/9Cw=. Default value: None
KeyMD5	string	No if used as a request parameter	Explanation: MD5 value of the key for encrypting objects when SSE-C is used. This value is used to check whether any error occurs during the transmission of the key. Restrictions: The value is encrypted by MD5 and then encoded by Base64, for example, 4XvB3tbNTN+tIEVa0/fGaQ==. Default value: None

**Table 11** SseKmsHeader
Parameter	Type	Mandatory (Yes/No)	Description
Encryption	string	Yes if used as a request parameter	Explanation: SSE-KMS used for encrypting objects Value range: kms, indicating objects are encrypted using SSE-KMS Default value: None
Key	string	No if used as a request parameter	Explanation: ID of the KMS master key when SSE-KMS is used Value range: Valid value formats are as follows: regionID:domainID:key/key_id key_id In the preceding formats: regionID indicates the ID of the region where the key is used. domainID indicates the ID of the account where the key is used. To obtain it, see How Do I Get My Account ID and User ID? key_id indicates the ID of the key created on Data Encryption Workshop (DEW). Default value: If this parameter is not specified, the default master key will be used. If there is no such a default master key, OBS will create one and use it by default.

Code Examples

This example copies an object from one bucket to another.

    
     
       
       
         package main
import (
    "fmt"
    "os"
    obs "github.com/huaweicloud/huaweicloud-sdk-go-obs/obs"
)
func main() {
    //Obtain an AK/SK pair using environment variables or import an AK/SK pair in other ways. Using hard coding may result in leakage.
    //Obtain an AK/SK pair on the management console. For details, see https://support.huaweicloud.com/eu/usermanual-ca/ca_01_0003.html.
    ak := os.Getenv("AccessKeyID")
    sk := os.Getenv("SecretAccessKey")
    // (Optional) If you use a temporary AK/SK pair and a security token to access OBS, you are advised not to use hard coding to reduce leakage risks. You can obtain an AK/SK pair using environment variables or import an AK/SK pair in other ways.
    // securityToken := os.Getenv("SecurityToken")
    // Enter the endpoint corresponding to the bucket. EU-Dublin is used here as an example. Replace it with the one currently in use.
    endPoint := "https://obs.eu-west-101.myhuaweicloud.eu" 
    // Create an obsClient instance.
    // If you use a temporary AK/SK pair and a security token to access OBS, use the obs.WithSecurityToken method to specify a security token when creating an instance.
    obsClient, err := obs.New(ak, sk, endPoint/*, obs.WithSecurityToken(securityToken)*/)
    if err != nil {
        fmt.Printf("Create obsClient error, errMsg: %s", err.Error())
    }
    input := &obs.CopyObjectInput{}
    // Specify the source bucket name.
    input.Bucket = "examplebucket"
    // Specify a source object (example/objectname as an example).
    input.Key = "example/objectname"
    // Specify a source bucket (sourcebucketname as an example).
    input.CopySourceBucket = "sourcebucketname"
    // Specify an object to copy (sourceobjectkey as an example) in the source bucket.
    input.CopySourceKey = "sourceobjectkey"
    // Copy the object.
    output, err := obsClient.CopyObject(input)
    if err == nil {
        fmt.Printf("Copy part(bucket:%s, object: %s) successful from bucket:%s's object: %s!\n",
            input.Bucket, input.Key, input.CopySourceBucket, input.CopySourceKey)
        fmt.Printf("ETag:%s, LastModified:%s\n", output.ETag, output.LastModified)
        return
    }
    fmt.Printf("Copy part(bucket:%s, object: %s) fail from bucket:%s's object: %s!\n",
        input.Bucket, input.Key, input.CopySourceBucket, input.CopySourceKey)
    if obsError, ok := err.(obs.ObsError); ok {
        fmt.Println("An ObsError was found, which means your request sent to OBS was rejected with an error response.")
        fmt.Println(obsError.Error())
    } else {
        fmt.Println("An Exception was found, which means the client encountered an internal problem when attempting to communicate with OBS, for example, the client was unable to access the network.")
        fmt.Println(err)
    }
}

        

      

    
   

Copying an Object (SDK for Go)

Function

Restrictions

Method

Request Parameters

Responses

Code Examples

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