Help Center> Object Storage Service> Go> Buckets (SDK for Go)> Obtaining the CORS Configuration of a Bucket (SDK for Go)
Updated on 2024-02-01 GMT+08:00

Obtaining the CORS Configuration of a Bucket (SDK for Go)

Function

Cross-origin resource sharing (CORS) is a browser-standard mechanism defined by the World Wide Web Consortium (W3C). It allows a web client in one origin to interact with resources in another one. For general web page requests, website scripts and contents in one origin cannot interact with those in another because of Same Origin Policies (SOPs). OBS supports CORS rules that allow the resources in OBS to be requested from other origins.

This API returns the CORS configuration of a bucket.

Restrictions

Method

func (obsClient ObsClient) GetBucketCors(bucketName string) (output *GetBucketCorsOutput, err error)

Request Parameters

Table 1 List of request parameters

Parameter

Type

Mandatory (Yes/No)

Description

bucketName

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 2 List of returned results

Parameter

Type

Description

output

*GetBucketCorsOutput

Explanation:

Returned results. For details, see Table 3.

err

error

Explanation:

Error messages returned by the API

Table 3 GetBucketCorsOutput

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

CorsRules

[]CorsRule

Explanation:

CORS rule list of the bucket. For details, see Table 4.

Table 4 CorsRule

Parameter

Type

Mandatory (Yes/No)

Description

ID

string

No if used as a request parameter

Explanation:

CORS rule ID

Value range:

The value must contain 1 to 255 characters.

Default value:

None

AllowedMethod

[]string

Yes if used as a request parameter

Explanation:

The allowed HTTP methods cross-origin request, same as the operation types of buckets and objects.

Value range:

The following HTTP methods are supported:

  • GET
  • PUT
  • HEAD
  • POST
  • DELETE

Default value:

None

AllowedOrigin

[]string

Yes if used as a request parameter

Explanation:

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

AllowedHeader

[]string

No if used as a request parameter

Explanation:

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

MaxAgeSeconds

int

No if used as a request parameter

Explanation:

Time your client can cache the response for a cross-origin request

Restrictions:

Each CORS rule can specify only one value for MaxAgeSeconds.

Value range:

0 to (231 – 1), in seconds

Default value:

100

ExposeHeader

[]string

No if used as a request parameter

Explanation:

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

Code Examples

This example returns the CORS configuration of bucket examplebucket.

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package main
import (
    "fmt"
    "os"
    "strings"
    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())
    }
    // Specify a bucket name.
    bucketname := "examplebucket"
    // Obtain the bucket's CORS configuration.
    output, err := obsClient.GetBucketCors(bucketname)
    if err == nil {
        fmt.Printf("Get bucket(%s) CORS configuration successful!\n", bucketname)
        fmt.Printf("RequestId:%s\n", output.RequestId)
        for _, corsRule := range output.CorsRules {
            fmt.Printf("ID:%s, AllowedOrigin:%s, AllowedMethod:%s, AllowedHeader:%s, MaxAgeSeconds:%d, ExposeHeader:%s\n",
                corsRule.ID, strings.Join(corsRule.AllowedOrigin, "|"), strings.Join(corsRule.AllowedMethod, "|"),
                strings.Join(corsRule.AllowedHeader, "|"), corsRule.MaxAgeSeconds, strings.Join(corsRule.ExposeHeader, "|"))
        }
        return
    }
    fmt.Printf("Get bucket(%s) CORS configuration fail!\n", bucketname)
    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)
    }
}