Obtaining Bucket Metadata (SDK for Go)

Updated on 2024-09-05 GMT+08:00

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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

func (obsClient ObsClient) GetBucketMetadata(input *GetBucketMetadataInput) (output *GetBucketMetadataOutput, err error)

Request Parameters

**Table 1** List of request parameters
Parameter	Type	Mandatory (Yes/No)	Description
input	*GetBucketMetadataInput	Yes	Explanation: Request parameters for obtaining bucket metadata. For details, see Table 2.

**Table 2** GetBucketMetadataInput
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

Responses

**Table 3** List of returned results
Parameter	Type	Description
output	*GetBucketMetadataOutput	Explanation: Returned results. For details, see Table 4.
err	error	Explanation: Error messages returned by the API

**Table 4** GetBucketMetadataOutput
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
Location	string	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.
Version	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
StorageClass	StorageClassType	Explanation: Storage class of the bucket. For details, see Table 5. Value range: If the storage class of the bucket is Standard, leave this parameter blank.
AllowOrigin	string	Explanation: If Origin in the request meets the CORS rules of the bucket, AllowedOrigin 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
AllowHeader	string	Explanation: If RequestHeader in the request meets the CORS rules of the bucket, AllowedHeader 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
AllowMethod	string	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
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, wildcard characters (), ampersands (&), colons (:), and less-than signs (<) are not allowed. Default value*: None
MaxAgeSeconds	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: 0 to (2³¹ – 1), in seconds Default value: 100
Epid	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

**Table 5** 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.

Code Examples

This example returns the metadata of bucket examplebucket.

    
     
       
       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/intl/en-us/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. CN-Hong Kong is used here as an example. Replace it with the one currently in use.
    endPoint := "https://obs.ap-southeast-1.myhuaweicloud.com"
    // 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.GetBucketMetadataInput{}
    // Specify a bucket name.
    input.Bucket = "examplebucket"
    // Obtain the bucket metadata.
    output, err := obsClient.GetBucketMetadata(input)
    if err == nil {
        fmt.Printf("Get bucket(%s)'s metadata successful!\n", input.Bucket)
        fmt.Printf("RequestId:%s\n", output.RequestId)
        fmt.Printf("StorageClass:%s\n", output.StorageClass)
        fmt.Printf("Location:%s\n", output.Location)
        fmt.Printf("AZRedundancy:%s\n", output.AZRedundancy)
        fmt.Printf("Epid:%s\n", output.Epid)
        return
    }
    fmt.Printf("Get bucket(%s)'s metadata fail!\n", input.Bucket)
    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)
    }
}

      

    
   

Helpful Links

Parent topic: Buckets (SDK for Go)

Previous topic: Listing Object Versions in a Bucket (SDK for Go)

Next topic: Obtaining the Region of a Bucket (SDK for Go)

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