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

Obtaining the Policy of a Bucket (SDK for Go)

Function

OBS provides access control over buckets. You can use an access policy to define whether a user can perform certain operations on a specific bucket. OBS access control can be implemented using IAM permissions, bucket policies, and ACLs. For more information, see Introduction to OBS Access Control.

A bucket policy is applied to a configured bucket and the objects in it. You can use a bucket policy to grant permissions for the bucket and the objects in it to IAM users or other accounts. If you want IAM users to have different permissions for different buckets, you can configure required bucket policies.

This API returns the policy of a bucket.

Restrictions

  • OBS returns "404 NoSuchBucketPolicy" when you call this API in the following scenarios:
    • The specified bucket policy does not exist.
    • Access to the specified bucket is denied.
  • To obtain the policy of a bucket, you must be the bucket owner or have the required permission (obs:bucket:GetBucketPolicy in IAM or GetBucketPolicy 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) GetBucketPolicy(bucketName string) (output *GetBucketPolicyOutput, 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

*GetBucketPolicyOutput

Explanation:

Returned results. For details, see Table 3.

err

error

Explanation:

Error messages returned by the API

Table 3 GetBucketPolicyOutput

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

Policy

string

Explanation:

Policy information in JSON format

Restrictions:

  • The bucket name contained in the Resource parameter of the policy must be the one specified for the current bucket policy.
  • For details about the policy format, see Bucket Policy Parameters.

Default value:

None

Code Examples

This example returns the policy of bucket bucketname.

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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())
    }
    // Specify a bucket name.
    bucketname := "examplebucket"
    // Obtain the bucket policy.
    output, err := obsClient.GetBucketPolicy(bucketname)
    if err == nil {
        fmt.Printf("Get policy successful with bucket:%s!\n", bucketname)
        fmt.Printf("RequestId:%s\n", output.RequestId)
        fmt.Printf("Policy:%s\n", output.Policy)
        return
    }
    fmt.Printf("Get policy fail with bucket:%s!\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)
    }
}