Downloading an Archive Object (SDK for Node.js)

If you have any questions during development, post them on the Issues page of GitHub.

To prolong the validity period of the Archive data restored, you can repeatedly restore the Archive data, but you will be billed for each restore. After a second restore, the validity period of Standard object copies will be prolonged, and you need to pay for storing these copies during the prolonged period.

Function

To download an object in the Archive storage class, you need to restore it first. After an object is restored, a copy of the object is saved in the Standard storage class. By doing so, the object in the Archive storage class and its copy in the Standard storage class co-exist in the bucket. The copy will be automatically deleted once its retention period ends.

This API restores an Archive object in a specified bucket.

Restrictions

To restore an Archive object, you must be the bucket owner or have the required permission (obs:object:RestoreObject in IAM or RestoreObject in a bucket policy.) For details, see Introduction to OBS Access Control, IAM Custom Policies, and Configuring an Object Policy.
To extend the validity period of the Archive data restored, you can repeatedly restore the data, but you will be billed for each restoration. After a restoration, the validity period of Standard object copies will be extended, and you need to pay for storing these copies during the extended period.

Method

ObsClient.restoreObject(params)

Request Parameters

**Table 1** List of request parameters
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 with 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. Value range: The value can contain 3 to 63 characters. Default value: None
Key	string	Yes	Explanation: Object name. An object is uniquely identified by an object name in a bucket. An object name is a complete path of the object 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. Restrictions: The object specified in ObsClient.restoreObject must be in the Archive storage class. Otherwise, an error is reported. Value range: The value can contain 1 to 1,024 characters. Default value: None
VersionId	string	No	Explanation: Version ID of the Archive object to restore. Restrictions: None Value range: The value must contain 32 characters. Default value: None. If this parameter is left blank, the latest version of the object is specified.
Days	number	Yes	Explanation: After an object is restored, a Standard copy is generated for the object. This parameter specifies how long the Standard copy can be retained, that is, the validity period of the restored object. Restrictions: None Value range: The value ranges from 1 to 30, in days. Default value: None
Tier	RestoreTierType	No	Explanation: Tier of the restoration speed. You can select a suitable tier based on your needs. Restrictions: None Value range: See Table 2. Default value: Standard

**Table 2** RestoreTierType
Constant	Default Value	Description
ObsClient.enums.RestoreTierExpedited	Expedited	Objects can be quickly restored from Archive storage within 1 to 5 minutes.
ObsClient.enums.RestoreTierStandard	Standard	Objects can be restored from Archive storage within 3 to 5 hours.

Responses

**Table 3** Responses
Type	Description
Table 4 NOTE: This API returns a Promise response, which requires the Promise or async/await syntax.	Explanation: Returned results. For details, see Table 4.

**Table 4** Response
Parameter	Type	Description
CommonMsg	ICommonMsg	Explanation: Common information generated after an API call is complete, including the HTTP status code and error code. For details, see Table 5.
InterfaceResult	Table 6	Explanation: Results outputted for a successful call. For details, see Table 6. Restrictions: This parameter is not included if the value of Status is greater than 300.

**Table 5** ICommonMsg
Parameter	Type	Description
Status	number	Explanation: HTTP status code returned by the OBS server. Value range: A status code is a group of digits indicating the status of a response. It ranges from 2xx (indicating successes) to 4xx or 5xx (indicating errors). For details, see Status Codes.
Code	string	Explanation: Error code returned by the OBS server.
Message	string	Explanation: Error description returned by the OBS server.
HostId	string	Explanation: Request server ID returned by the OBS server.
RequestId	string	Explanation: Request ID returned by the OBS server.
Id2	string	Explanation: Request ID2 returned by the OBS server.
Indicator	string	Explanation: Error code details returned by the OBS server.

**Table 6** BaseResponseOutput
Parameter	Type	Description
RequestId	string	Explanation: Request ID returned by the OBS server

Code Examples

You can call ObsClient.restoreObject to restore an Archive object. Sample code is as follows:

// Import the OBS library.
// Use npm to install the client.
const ObsClient = require("esdk-obs-nodejs");
// Use the source code to install the client.
// var ObsClient = require('./lib/obs');
// Create an instance of ObsClient.
const obsClient = new ObsClient({
  // 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.
  access_key_id: process.env.ACCESS_KEY_ID,
  secret_access_key: process.env.SECRET_ACCESS_KEY,
  // (Optional) If you use a temporary AK/SK pair and a security token to access OBS, you are advised not to use hard coding, which may result in information leakage. You can obtain an AK/SK pair using environment variables or import an AK/SK pair in other ways.
  // security_token: process.env.SECURITY_TOKEN,
  // Enter the endpoint corresponding to the region where the bucket is located. EU-Dublin is used here as an example. Replace it with the one currently in use.
  server: "https://obs.eu-west-101.myhuaweicloud.eu"
});

async function downloadColdObject() {
  // Specify the bucket name.
  const bucketName = "examplebucket";
  // Specify the object (example/objectname in this example).
  const objectKey = "example/objectname";
  try {
     // Restore an Archive object.
    const restoreObjectOutput = await obsClient.restoreObject({
      Bucket: bucketName,
      Key: objectKey,
      // Specify how long the restored object will be retained, in days. The value ranges from 1 to 30 (1 this example).
      Days: 1,
      // Specify the restoration speed (obs.RestoreTierExpedited in this example). By default, the object is restored at an expedited speed.
      Tier: obs.enums.RestoreTierExpedited
    });
    if (restoreObjectOutput.CommonMsg.Status > 300) {
      handleMessage(restoreObjectOutput.CommonMsg);
      return;
    };
    // Wait for the object to be restored.
    await sleep(5 * 60);
    // Download the object.
    const getObjectOutput = await obsClient.getObject({
      Bucket: bucketName,
      Key: objectKey,
    });
    if (getObjectOutput.CommonMsg.Status > 300) {
      handleMessage(getObjectOutput.CommonMsg);
      return;
    };
    console.log("Get object(%s) under the bucket(%s) successful!", params.Key, params.Bucket);
    console.log("RequestId: %s", result.CommonMsg.RequestId);
    console.log('Object Content: %s', result.InterfaceResult.Content); 
  } catch (error) {
    console.log("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.");
    console.log(error);
  };
};

function handleMessage(commonMsg) {
    console.log("An ObsError was found, which means your request sent to OBS was rejected with an error response.");
    console.log("Status: %d", commonMsg.Status);
    console.log("Code: %s", commonMsg.Code);
    console.log("Message: %s", commonMsg.Message);
    console.log("RequestId: %s", commonMsg.RequestId);
};

function sleep() {
    return new Promise(resolve => {
        setTimeout(resolve, time * 1000);
    });
} ;

downloadColdObject();