Object Storage Service:Configure bucket policies by using OSS SDK for C++

Usage notes

• Before you configure bucket policies, make sure that you are familiar with this feature. For more information, see Bucket policies.

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

• To configure a bucket policy, you must have the oss:PutBucketPolicy permission. To query bucket policies, you must have the oss:GetBucketPolicy permission. To delete a bucket policy, you must have the oss:DeleteBucketPolicy permission. For more information, see Attach a custom policy to a RAM user.

Configure a bucket policy

The following sample code provides an example on how to configure a bucket policy:

#include <alibabacloud/oss/OssClient.h>
using namespace AlibabaCloud::OSS;

int main(void)
{
    /* Initialize the information about the account that is used to access OSS. */
            
    /* Specify the endpoint of the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com. */
    std::string Endpoint = "yourEndpoint";
    /* Specify the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the region to cn-hangzhou. */
    std::string Region = "yourRegion";
    /* Specify the name of the bucket. Example: examplebucket. */
    std::string BucketName = "examplebucket";

    /* Initialize resources, such as network resources. */
    InitializeSdk();

    ClientConfiguration conf;
    conf.signatureVersion = SignatureVersionType::V4;
    /* Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. */
    auto credentialsProvider = std::make_shared<EnvironmentVariableCredentialsProvider>();
    OssClient client(Endpoint, credentialsProvider, conf);
    client.SetRegion(Region);

    /* In the following example, the bucket owner whose UID is 174649585760xxxx uses a bucket policy to authorize a RAM user whose UID is 20214760404935xxxx to list all objects in the examplebucket bucket. */
    std::string policy = 
        R"(
        {
            "Statement": [
            {
                "Action": [
                    "oss:GetObject",
                    "oss:ListObjects"
                ],
                "Principal": [
                    "20214760404935xxxx"           
                ],
                "Effect" : "Allow",
                "Resource" : ["acs:oss:*:174649585760xxxx:examplebucket/*"]
            }
            ],
                "Version": "1"
        }
        )";
    SetBucketPolicyRequest request(BucketName);
    request.setPolicy(policy);
    auto outcome = client.SetBucketPolicy(request);

    if (!outcome.isSuccess()) {
        /* Handle exceptions. */
        std::cout << "Set Bucket Policy fail" <<
            ",code:" << outcome.error().Code() <<
            ",message:" << outcome.error().Message() <<
            ",requestId:" << outcome.error().RequestId() << std::endl;
    }

    /* Release resources, such as network resources. */
    ShutdownSdk();
    return 0;
}

Query bucket policies

The following sample code shows how to query bucket policies:

#include <alibabacloud/oss/OssClient.h>
using namespace AlibabaCloud::OSS;

int main(void)
{
    /* Initialize the information about the account that is used to access OSS. */
            
    /* Specify the endpoint of the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com. */
    std::string Endpoint = "yourEndpoint";
    /* Specify the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the region to cn-hangzhou. */
    std::string Region = "yourRegion";
    /* Specify the name of the bucket. Example: examplebucket. */
    std::string BucketName = "examplebucket";

    /* Initialize resources, such as network resources. */
    InitializeSdk();

    ClientConfiguration conf;
    conf.signatureVersion = SignatureVersionType::V4;
    /* Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. */
    auto credentialsProvider = std::make_shared<EnvironmentVariableCredentialsProvider>();
    OssClient client(Endpoint, credentialsProvider, conf);
    client.SetRegion(Region);

    /* Query the configurations of the bucket policies. */
    GetBucketPolicyRequest request(BucketName);
    auto outcome = client.GetBucketPolicy(request);

    if (!outcome.isSuccess()) {
        /* Handle exceptions. */
        std::cout << "Get Bucket Policy fail" <<
            ",code:" << outcome.error().Code() <<
            ",message:" << outcome.error().Message() <<
            ",requestId:" << outcome.error().RequestId() << std::endl;
            return -1;
    }

    /* Display the configurations of the bucket policies. */
    std::cout << outcome.result().Policy() << std::endl;

    /* Release resources, such as network resources. */
    ShutdownSdk();
    return 0;
}

Delete a bucket policy

The following sample code provides an example on how to delete a bucket policy:

#include <alibabacloud/oss/OssClient.h>
using namespace AlibabaCloud::OSS;

int main(void)
{
    /* Initialize the information about the account that is used to access OSS. */
            
    /* Specify the endpoint of the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com. */
    std::string Endpoint = "yourEndpoint";
    /* Specify the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the region to cn-hangzhou. */
    std::string Region = "yourRegion";
    /* Specify the name of the bucket. Example: examplebucket. */
    std::string BucketName = "examplebucket";

    /* Initialize resources, such as network resources. */
    InitializeSdk();

    ClientConfiguration conf;
    conf.signatureVersion = SignatureVersionType::V4;
    /* Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. */
    auto credentialsProvider = std::make_shared<EnvironmentVariableCredentialsProvider>();
    OssClient client(Endpoint, credentialsProvider, conf);
    client.SetRegion(Region);

    /* Delete the bucket policy. */
    DeleteBucketPolicyRequest request(BucketName);
    auto outcome = client.DeleteBucketPolicy(request);

    if (!outcome.isSuccess()) {
        /* Handle exceptions. */
        std::cout << "Delete Bucket Policy fail" <<
            ",code:" << outcome.error().Code() <<
            ",message:" << outcome.error().Message() <<
            ",requestId:" << outcome.error().RequestId() << std::endl;
    }

    /* Release resources, such as network resources. */
    ShutdownSdk();
    return 0;
}

References

• For more information about the API operation that you can call to configure a bucket policy, see PutBucketPolicy.

• For more information about the API operation that you can call to query bucket policies, see GetBucketPolicy.

• For more information about the API operation that you can call to delete a bucket policy, see DeleteBucketPolicy.