Obtaining Bucket Metadata (SDK for Node.js)

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

Function

This API returns information about a bucket, including the storage class, region, CORS rules, and redundancy policy.

Restrictions

To obtain bucket metadata, you must be the bucket owner or have the required permission (obs:bucket:HeadBucket in IAM or HeadBucket in a bucket policy). For details, see Introduction to OBS Access Control, IAM Custom Policies, and Creating a Custom Bucket Policy.

Method

ObsClient.getBucketMetadata(params)

Request Parameters

**Table 1** BucketRequestInput
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

Responses

**Table 2** Responses
Type	Description
Table 3 NOTE: This API returns a Promise response, which requires the Promise or async/await syntax.	Explanation: Returned results. For details, see Table 3.

**Table 3** 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 4.
InterfaceResult	GetBucketMetadataOutput	Explanation: Results outputted for a successful call. For details, see Table 5. Restrictions: This parameter is not included if the value of Status is greater than 300.

**Table 4** 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 5** GetBucketMetadataOutput
Parameter	Type	Description
RequestId	string	Explanation: Request ID returned by the OBS server Default value: None
StorageClass	StorageClassType	Explanation: Storage class of the bucket. Value range: See Table 6. Default value: If the storage class of the bucket is Standard, this parameter is not specified.
Location	string	Explanation: Region where a bucket is located. Restrictions: If the endpoint used is obs.myhuaweicloud.eu, this parameter is not required. If any other endpoints are used, this parameter is required. Default value: If obs.myhuaweicloud.eu is used as the endpoint and no region is specified, eu-west-101 (the EU-Dublin region) is used by default.
ObsVersion	string	Explanation: OBS version of the bucket. Value range: 3.0 indicates the latest OBS version. -- indicates any version earlier than 3.0. Default value: None
AllowOrigin	string	Explanation: If Origin in the request meets the CORS rules of the bucket, AllowedOrigin specified in the CORS rules is returned. AllowedOrigin indicates the origin from which requests can access the bucket. Restrictions: Domain name of the origin. Each origin can contain at most one wildcard character (). Example: https://.vbs.example.com Default value**: None
AllowHeader	string	Explanation: If RequestHeader in the request meets the CORS rules of the bucket, AllowedHeader specified in the CORS rules is returned. AllowedHeader indicates the allowed headers for cross-origin requests. Only CORS requests matching the allowed headers are valid. Restrictions: Each header can contain at most one wildcard character (). Spaces, ampersands (&), colons (:), less-than signs (<), and full-width characters are not allowed. Default value*: None
AllowMethod	string	Explanation: AllowedMethod in the CORS rules of the bucket. It specifies the HTTP method allowed for cross-origin requests, that is, the operation type of buckets and objects. Value range: The following HTTP methods are supported: GET PUT HEAD POST DELETE Default value: None
ExposeHeader	string	Explanation: ExposeHeader in the CORS rules of the bucket. It specifies the CORS-allowed additional headers in the response. These headers provide additional information to clients. By default, your browser can only access headers Content-Length and Content-Type. If your browser needs to access other headers, add them to a list of the allowed additional headers. Restrictions: Spaces, asterisks (), ampersands (&), colons (:), less-than signs (<), and full-width characters are not allowed. Default value*: None
MaxAgeSeconds	number	Explanation: MaxAgeSeconds in the CORS rules of the bucket. It specifies the time your client can cache the response for a cross-origin request. Restrictions: Each CORS rule can contain at most one MaxAgeSeconds. Value range: 0 to (2³¹ – 1), in seconds Default value: 100
MultiEnterprise	string	Explanation: Enterprise project ID that can be specified during bucket creation. If you have enabled EPS, you can obtain the project ID from the EPS console. Restrictions: The value of epid is a UUID. epid is not required if you have not enabled EPS yet. Example: 9892d768-2d13-450f-aac7-ed0e44c2585f Value range: To obtain the enterprise project ID, see How Do I Obtain an Enterprise Project ID? Default value: None
AzRedundancy	string	No Explanation: Data redundancy type that can be specified at bucket creation. Restrictions: Multi-AZ redundancy is not available for Archive storage. If the region where the bucket is located does not support multi-AZ storage, the bucket adopts single-AZ storage by default. Value range: To configure multi-AZ storage for the bucket, set this parameter to 3az. To configure single-AZ storage (default value assigned by OBS) for the bucket, you do not need to specify this parameter. Default value: single AZ

**Table 6** StorageClassType
Constant	Default Value	Description
ObsClient.enums.StorageClassStandard	STANDARD	Standard storage class. 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.
ObsClient.enums.StorageClassWarm	WARM	Infrequent Access storage class. Used for storing data that is semi-frequently accessed (fewer than 12 times a year) but becomes instantly available when needed.
ObsClient.enums.StorageClassCold	COLD	Archive storage class. Used for storing rarely accessed (once a year) data.

Code Examples

You can call ObsClient.getBucketMetadata to obtain the metadata of a bucket. This example uses bucket examplebucket.

    
     
       
       
         // 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 in this example. Replace it with the one currently in use.
  server: "https://obs.eu-west-101.myhuaweicloud.eu"
});

async function getBucketMetadata() {
  try {
    const params = {
      // Specify the bucket name.
      Bucket: "examplebucket"
    };
    // Obtain the bucket metadata.
    const result = await obsClient.getBucketMetadata(params);
    if (result.CommonMsg.Status <= 300) {
      console.log("Delete bucket(%s)'s metadata successful!", params.Bucket);
      console.log("RequestId: %s", result.CommonMsg.RequestId);
      console.log('StorageClass: %s', result.InterfaceResult.StorageClass);
      console.log('Location: %s', result.InterfaceResult.Location);
      console.log('AZRedundancy: %s', result.InterfaceResult.AZRedundancy);
      console.log('Epid: %s', result.InterfaceResult.Epid);
      return;
    };
    console.log("An ObsError was found, which means your request sent to OBS was rejected with an error response.");
    console.log("Status: %d", result.CommonMsg.Status);
    console.log("Code: %s", result.CommonMsg.Code);
    console.log("Message: %s", result.CommonMsg.Message);
    console.log("RequestId: %s", result.CommonMsg.RequestId);
  } 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);
  };
};
getBucketMetadata();

        

      

    
   