Object Storage Service:Pay-by-requester mode (Go SDK V1)

Usage notes

• In this topic, the public endpoint of the China (Hangzhou) region is used. If you want to access OSS from other Alibaba Cloud services in the same region as OSS, use an internal endpoint. For more information about OSS regions and endpoints, see Regions and endpoints.

• In this topic, access credentials are obtained from environment variables. For more information about how to configure access credentials, see Configure access credentials.

• In this topic, an OSSClient instance is created by using an OSS endpoint. If you want to create an OSSClient instance by using custom domain names or Security Token Service (STS), see Configure OSSClient instances.

• To enable pay-by-requester, you must have the oss:PutBucketRequestPayment permission. To query the pay-by-requester configurations, you must have the oss:GetBucketRequestPayment permission. For more information, see Attach a custom policy to a RAM user.

Set the pay-by-requester mode

The following code provides an example on how to enable pay-by-requester for a bucket:

package main

import (
	"fmt"
	"os"

	"github.com/aliyun/aliyun-oss-go-sdk/oss"
)

func main() {
	// Obtain access credentials from environment variables. Before you run this sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are set.
	provider, err := oss.NewEnvironmentVariableCredentialsProvider()
	if err != nil {
		fmt.Println("Error:", err)
		os.Exit(-1)
	}
	// Create an OSSClient instance.
	// Set yourEndpoint to the Endpoint of the bucket. For example, for a bucket in the China (Hangzhou) region, set the Endpoint to https://oss-cn-hangzhou.aliyuncs.com. For other regions, set the Endpoint as needed.
	// Set yourRegion to the region where the bucket is located. For example, for a bucket in the China (Hangzhou) region, set the region to cn-hangzhou. For other regions, set the region as needed.
	clientOptions := []oss.ClientOption{oss.SetCredentialsProvider(&provider)}
	clientOptions = append(clientOptions, oss.Region("yourRegion"))
	// Set the signature version.
	clientOptions = append(clientOptions, oss.AuthVersion(oss.AuthV4))
	client, err := oss.New("yourEndpoint", "", "", clientOptions...)
	if err != nil {
		fmt.Println("New Error:", err)
		os.Exit(-1)
	}

	// Initialize the pay-by-requester mode.
	reqPayConf := oss.RequestPaymentConfiguration{
		Payer: "Requester",
	}

	// Set the pay-by-requester mode.
	err = client.SetBucketRequestPayment("<yourBucketName>", reqPayConf)
	if err != nil {
		fmt.Println("Error:", err)
		os.Exit(-1)
	}
}

Get the pay-by-requester mode configuration

The following code provides an example on how to query the pay-by-requester configurations of a bucket:

package main

import (
	"fmt"
	"os"

	"github.com/aliyun/aliyun-oss-go-sdk/oss"
)

func main() {
	// Obtain access credentials from environment variables. Before you run this sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are set.
	provider, err := oss.NewEnvironmentVariableCredentialsProvider()
	if err != nil {
		fmt.Println("Error:", err)
		os.Exit(-1)
	}

	// Create an OSSClient instance.
	// Set yourEndpoint to the Endpoint of the bucket. For example, for a bucket in the China (Hangzhou) region, set the Endpoint to https://oss-cn-hangzhou.aliyuncs.com. For other regions, set the Endpoint as needed.
	// Set yourRegion to the region where the bucket is located. For example, for a bucket in the China (Hangzhou) region, set the region to cn-hangzhou. For other regions, set the region as needed.
	clientOptions := []oss.ClientOption{oss.SetCredentialsProvider(&provider)}
	clientOptions = append(clientOptions, oss.Region("yourRegion"))
	// Set the signature version.
	clientOptions = append(clientOptions, oss.AuthVersion(oss.AuthV4))
	client, err := oss.New("yourEndpoint", "", "", clientOptions...)
	if err != nil {
		fmt.Println("Error:", err)
		os.Exit(-1)
	}

	// Get the pay-by-requester mode configuration.
	ret, err := client.GetBucketRequestPayment("yourBucketName")
	if err != nil {
		fmt.Println("Error:", err)
		os.Exit(-1)
	}
	// Print the configuration information of the pay-by-requester mode.
	fmt.Println("Bucket request payer:", ret.Payer)
}

Access objects as a third-party requester

If you specify that third parties are charged for access to objects in a bucket, requesters must include the x-oss-request-payer:requester header in the HTTP requests to perform operations on your objects. If this header is not included, an error is returned.

The following code provides an example on how to specify that third parties are charged when they access objects by calling the PutObject, GetObject, and DeleteObject operations. You can use the method to specify that third parties are charged when they perform read and write operations on objects by calling other API operations in the similar way.

package main

import (
	"fmt"
	"io"
	"os"
	"strings"

	"github.com/aliyun/aliyun-oss-go-sdk/oss"
)

func main() {
	// Obtain access credentials from environment variables. Before you run this sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are set.
	provider, err := oss.NewEnvironmentVariableCredentialsProvider()
	if err != nil {
		fmt.Println("Error:", err)
		os.Exit(-1)
	}
	// Create an OSSClient instance.
	// Set yourEndpoint to the Endpoint of the bucket. For example, for a bucket in the China (Hangzhou) region, set the Endpoint to https://oss-cn-hangzhou.aliyuncs.com. For other regions, set the Endpoint as needed.
	// Set yourRegion to the region where the bucket is located. For example, for a bucket in the China (Hangzhou) region, set the region to cn-hangzhou. For other regions, set the region as needed.
	clientOptions := []oss.ClientOption{oss.SetCredentialsProvider(&provider)}
	clientOptions = append(clientOptions, oss.Region("yourRegion"))
	// Set the signature version.
	clientOptions = append(clientOptions, oss.AuthVersion(oss.AuthV4))
	payerClient, err := oss.New("yourEndpoint", "", "", clientOptions...)
	if err != nil {
		fmt.Println("New Error:", err)
		os.Exit(-1)
	}

	// Specify the bucket name.
	payerBucket, err := payerClient.Bucket("examplebucket")
	if err != nil {
		fmt.Println("Error:", err)
		os.Exit(-1)
	}

	// After the bucket owner enables the pay-by-requester mode, external requesters must set the oss.RequestPayer(oss.Requester) parameter to access authorized content.
	// If the bucket owner has not enabled the pay-by-requester mode, external requesters can access authorized content without including the oss.RequestPayer(oss.Requester) parameter.

	// Upload an object.
	// Specify the full path of the object. The full path cannot contain the bucket name. Example: exampledir/exampleobject.txt.
	key := "exampledir/exampleobject.txt"
	err = payerBucket.PutObject(key, strings.NewReader("objectValue"), oss.RequestPayer("requester"))
	if err != nil {
		fmt.Println("put Error:", err)
		os.Exit(-1)
	}

	// List all objects in the bucket.
	lor, err := payerBucket.ListObjects(oss.RequestPayer(oss.Requester))
	if err != nil {
		fmt.Println("Error:", err)
		os.Exit(-1)
	}
	// Print the list of object names.
	for _, l := range lor.Objects {
		fmt.Println("the Key name is :", l.Key)
	}

	// Download an object.
	body, err := payerBucket.GetObject(key, oss.RequestPayer(oss.Requester))
	if err != nil {
		fmt.Println("Get Error:", err)
		os.Exit(-1)
	}
	// After reading the data, close the stream. If you do not close the stream, a connection leak may occur. This can exhaust available connections for requests and cause the program to fail.
	defer body.Close()

	// Read and print the obtained content.
	data, err := io.ReadAll(body)
	if err != nil {
		fmt.Println("Error:", err)
		os.Exit(-1)
	}
	fmt.Println("data:", string(data))

	// Delete the object.
	err = payerBucket.DeleteObject(key, oss.RequestPayer(oss.Requester))
	if err != nil {
		fmt.Println("Error:", err)
		os.Exit(-1)
	}
}

References

• For the complete sample code for the pay-by-requester mode, see GitHub example.

• For more information about the API operation that you can call to enable pay-by-requester, see PutBucketRequestPayment.

• For more information about the API operation that you can call to query the pay-by-requester configurations, see GetBucketRequestPayment.