Obtaining Bucket Metadata (SDK for Python)

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.
The mapping between OBS regions and endpoints must comply with what is listed in Regions and Endpoints.

Method

ObsClient.getBucketMetadata(bucketName, origin, requestHeaders)

Request Parameters

**Table 1** List of request parameters
Parameter	Type	Mandatory (Yes/No)	Description
bucketName	str	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 periods (.) and hyphens (-) 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 properties comply with those set in the first creation request. Default value: None
origin	str	No	Explanation: Origin of the cross-domain request specified by the preflight request. Generally, it is a domain name. Restrictions: You can configure one or more rules and use at most one wildcard character () in each rule. If you want to configure multiple rules, separate them using a line breaker. Default value*: None
requestHeaders	str	No	Explanation: HTTP headers in a cross-origin request Only CORS requests matching the allowed headers are valid. Restrictions: You can enter multiple allowed headers, with one separated from another using a line break. Each header can contain one wildcard character () at most. Spaces, ampersands (&), colons (:), and less-than signs (<) are not allowed. Default value*: None

Responses

**Table 2** List of returned results
Type	Description
GetResult	Explanation: SDK common results

**Table 3** GetResult
Parameter	Type	Description
status	int	Explanation: HTTP status code Value range: A status code is a group of digits ranging from 2xx (indicating successes) to 4xx or 5xx (indicating errors). It indicates the status of a response. For more information, see Status Code. Default value: None
reason	str	Explanation: Reason description. Default value: None
errorCode	str	Explanation: Error code returned by the OBS server. If the value of status is less than 300, this parameter is left blank. Default value: None
errorMessage	str	Explanation: Error message returned by the OBS server. If the value of status is less than 300, this parameter is left blank. Default value: None
requestId	str	Explanation: Request ID returned by the OBS server Default value: None
indicator	str	Explanation: Error indicator returned by the OBS server. Default value: None
hostId	str	Explanation: Requested server ID. If the value of status is less than 300, this parameter is left blank. Default value: None
resource	str	Explanation: Error source (a bucket or an object). If the value of status is less than 300, this parameter is left blank. Default value: None
header	list	Explanation: Response header list, composed of tuples. Each tuple consists of two elements, respectively corresponding to the key and value of a response header. Default value: None
body	object	Explanation: Result content returned after the operation is successful. If the value of status is larger than 300, this parameter is left blank. The value varies with the API being called. For details, see Bucket-Related APIs (SDK for Python) and Object-Related APIs (SDK for Python). Default value: None

**Table 4** GetResult.body
GetResult.body Type	Description
GetBucketMetadataResponse	Explanation: Response to the request for obtaining bucket metadata

**Table 5** GetBucketMetadataResponse
Parameter	Type	Description
location	str	Explanation: Region where a bucket is located Restrictions: If the used endpoint is obs.myhuaweicloud.com, this parameter is not required. If any other endpoint is used, this parameter is required. Value range: To learn about valid regions and endpoints, see Regions and Endpoints. An endpoint is the request address for calling an API. Endpoints vary depending on services and regions. To obtain the regions and endpoints, contact the enterprise administrator. Default value: If obs.myhuaweicloud.com is used as the endpoint and no region is specified, cn-north-1 (the CN North-Beijing1 region) is used by default.
storageClass	str	Explanation: Storage class of the bucket. For details, see Table 6. Default value: None
accessContorlAllowOrigin	str	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 the requests can access the bucket. Restrictions: Domain name of the origin. Each origin can contain only one wildcard character (), for example, https://.vbs.example.com. Default value**: None
accessContorlAllowHeaders	str	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 only one wildcard character (). Spaces, ampersands (&), colons (:), and less-than signs (<) are not allowed. Default value*: None
accessContorlAllowMethods	str	Explanation: AllowedMethod in the CORS rules of the bucket. It specifies the HTTP method of 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
accessContorlExposeHeaders	str	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, wildcard characters (), ampersands (&), colons (:), and less-than signs (<) are not allowed. Default value*: None
accessContorlMaxAge	int	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 only one MaxAgeSeconds. Value range: An integer greater than or equal to 0, in seconds Default value: 100
obsVersion	str	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
availableZone	str	Explanation: Data redundancy type that can be specified during 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, single-AZ storage is used by default. Value range: If multi-AZ storage is configured for the bucket, 3az is returned. If single-AZ storage is configured for the bucket, None is returned. Default value: None
epid	str	Explanation: Enterprise project ID that can be specified during bucket creation. If you have enabled Enterprise Project Management Service (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: See How Do I Obtain an Enterprise Project ID? Default value: None

**Table 6** StorageClass
Parameter	Type	Description
STANDARD	Standard storage class	Explanation: 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.
WARM	Infrequent Access storage class	Explanation: Used for storing data that is semi-frequently accessed (fewer than 12 times a year) but is instantly available when needed.
COLD	Archive storage class	Explanation: Used for storing rarely accessed (once a year) data.

Code Examples

This example returns the metadata of bucket examplebucket. The origin of the cross-origin request is http://www.a.com and the HTTP header is x-obs-header.

     
      
        
        
          from obs import ObsClient
import os
import traceback

# Obtain an AK and SK pair using environment variables or import the AK and SK pair in other ways. Using hard coding may result in leakage.
# Obtain an AK and SK pair on the management console. For details, see https://support.huaweicloud.com/intl/en-us/usermanual-ca/ca_01_0003.html.
ak = os.getenv("AccessKeyID")
sk = os.getenv("SecretAccessKey")
# (Optional) If you use a temporary AK and SK pair and a security token to access OBS, obtain them from environment variables.
security_token = os.getenv("SecurityToken")
# Set server to the endpoint corresponding to the bucket. Here uses CN-Hong Kong as an example. Replace it with the one in use.
server = "https://obs.ap-southeast-1.myhuaweicloud.com" 

# Create an obsClient instance.
# If you use a temporary AK and SK pair and a security token to access OBS, you must specify security_token when creating an instance.
obsClient = ObsClient(access_key_id=ak, secret_access_key=sk, server=server)
try:
    bucketName="examplebucket"
    # Specify the origin (usually a domain name) of the cross-origin request.
    origin='http://www.a.com'
    # Specify the HTTP headers of the cross-origin request.
    requestHeaders='x-obs-header'
    # Obtain the bucket metadata.
    resp = obsClient.getBucketMetadata(bucketName,origin,requestHeaders)
    # If status code 2xx is returned, the API is called successfully. Otherwise, the API call fails.
    if resp.status < 300:
        print('Get Bucket Metadata Succeeded')
        print('requestId:', resp.requestId)
        print('storageClass:', resp.body.storageClass)
        print('accessContorlAllowOrigin:', resp.body.accessContorlAllowOrigin)
        print('accessContorlMaxAge:', resp.body.accessContorlMaxAge)
        print('accessContorlExposeHeaders:', resp.body.accessContorlExposeHeaders)
        print('accessContorlAllowMethods:', resp.body.accessContorlAllowMethods)
        print('accessContorlAllowHeaders:', resp.body.accessContorlAllowHeaders)
    else:
        print('Get Bucket Metadata Failed')
        print('requestId:', resp.requestId)
        print('status:', resp.status)
except:
    print('Get Bucket Metadata Failed')
    print(traceback.format_exc())

         

       

     
    