将策略附加到现有表 - Amazon DynamoDB
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将策略附加到现有表

您可以使用 DynamoDB 控制台、PutResourcePolicy API、Amazon CLI、Amazon SDK 或 Amazon CloudFormation 模板将基于资源的策略附加到现有表或修改现有策略。

以下 IAM 策略示例使用 put-resource-policy Amazon CLI 命令将基于资源的策略附加到现有表。此示例允许用户 John 对名为 MusicCollection 的现有表执行 GetItem、PutItem、UpdateItem 和 UpdateTable API 操作。

切记用特定资源信息替换斜体文本。

aws dynamodb put-resource-policy \
    --resource-arn arn:aws:dynamodb:us-west-2:123456789012:table/MusicCollection \
    --policy \
        "{
            \"Version\": \"2012-10-17\",
            \"Statement\": [
              {
                    \"Effect\": \"Allow\",
                    \"Principal\": {
                        \"AWS\": \"arn:aws:iam::111122223333:user/John\"
                    },
                    \"Action\": [
                        \"dynamodb:GetItem\",
                        \"dynamodb:PutItem\",
                        \"dynamodb:UpdateItem\",
                        \"dynamodb:UpdateTable\"
                    ],
                    \"Resource\": \"arn:aws:dynamodb:us-west-2:123456789012:table/MusicCollection\"
                }
            ]
        }"

要有条件地更新表现有的基于资源的策略，可以使用可选 expected-revision-id 参数。以下示例仅当策略存在于 DynamoDB 中且其当前修订版 ID 与提供的 expected-revision-id 参数相匹配时，才会更新该策略。

aws dynamodb put-resource-policy \
    --resource-arn arn:aws:dynamodb:us-west-2:123456789012:table/MusicCollection \
    --expected-revision-id 1709841168699 \ 
    --policy \
        "{
            \"Version\": \"2012-10-17\",
            \"Statement\": [
              {
                    \"Effect\": \"Allow\",
                    \"Principal\": {
                        \"AWS\": \"arn:aws:iam::111122223333:user/John\"
                    },
                    \"Action\": [
                        \"dynamodb:GetItem\",
                        \"dynamodb:UpdateItem\",
                        \"dynamodb:UpdateTable\"
                    ],
                    \"Resource\": \"arn:aws:dynamodb:us-west-2:123456789012:table/MusicCollection\"
                }
            ]
        }"

  1. 登录 Amazon Web Services Management Console，并打开 DynamoDB 控制台：https://console.aws.amazon.com/dynamodb/。

  2. 在控制面板中，选择现有表。

  3. 导航到权限选项卡，然后选择创建表策略。

  4. 在基于资源的策略编辑器中，添加要附加的策略，然后选择创建策略。

    以下 IAM 策略示例允许用户 John 对名为 MusicCollection 的现有表执行 GetItem、PutItem、UpdateItem 和 UpdateTable API 操作。

    切记用特定资源信息替换斜体文本。

    {
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Principal": {
        "AWS": "arn:aws:iam::111122223333:user/John"
      },
      "Action": [
        "dynamodb:GetItem",
        "dynamodb:PutItem",
        "dynamodb:UpdateItem",
        "dynamodb:UpdateTable"
      ],
      "Resource": "arn:aws:dynamodb:us-west-2:123456789012:table/MusicCollection"
    }
  ]
}

以下 IAM 策略示例使用 putResourcePolicy 方法将基于资源的策略附加到现有表。此策略允许用户对现有表执行 GetItem API 操作。

import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.dynamodb.DynamoDbClient;
import software.amazon.awssdk.services.dynamodb.model.DynamoDbException;
import software.amazon.awssdk.services.dynamodb.model.PutResourcePolicyRequest;

/**
 * Before running this Java V2 code example, set up your development
 * environment, including your credentials.
 *
 * For more information, see the following documentation topic:
 *
 * Get started with the Amazon SDK for Java 2.x
 */
public class PutResourcePolicy {

    public static void main(String[] args) {
        final String usage = """

                Usage:
                    <tableArn> <allowedAWSPrincipal>

                Where:
                    tableArn - The Amazon DynamoDB table ARN to attach the policy to. For example, arn:aws:dynamodb:us-west-2:123456789012:table/MusicCollection.
                    allowedAmazonPrincipal - Allowed Amazon principal ARN that the example policy will give access to. For example, arn:aws:iam::123456789012:user/John.
                """;

        if (args.length != 2) {
            System.out.println(usage);
            System.exit(1);
        }

        String tableArn = args[0];
        String allowedAWSPrincipal = args[1];
        System.out.println("Attaching a resource-based policy to the Amazon DynamoDB table with ARN " +
                tableArn);
        Region region = Region.US_WEST_2;
        DynamoDbClient ddb = DynamoDbClient.builder()
                .region(region)
                .build();

        String result = putResourcePolicy(ddb, tableArn, allowedAWSPrincipal);
        System.out.println("Revision ID for the attached policy is " + result);
        ddb.close();
    }

    public static String putResourcePolicy(DynamoDbClient ddb, String tableArn, String allowedAWSPrincipal) {
        String policy = generatePolicy(tableArn, allowedAWSPrincipal);
        PutResourcePolicyRequest request = PutResourcePolicyRequest.builder()
                .policy(policy)
                .resourceArn(tableArn)
                .build();

        try {
            return ddb.putResourcePolicy(request).revisionId();
        } catch (DynamoDbException e) {
            System.err.println(e.getMessage());
            System.exit(1);
        }

        return "";
    }

    private static String generatePolicy(String tableArn, String allowedAWSPrincipal) {
        return "{\n" +
                "    \"Version\": \"2012-10-17\",\n" +
                "    \"Statement\": [\n" +
                "        {\n" +
                "            \"Effect\": \"Allow\",\n" +
                "            \"Principal\": {\"AWS\":\"" + allowedAWSPrincipal + "\"},\n" +
                "            \"Action\": [\n" +
                "                \"dynamodb:GetItem\"\n" +
                "            ],\n" +
                "            \"Resource\": \"" + tableArn + "\"\n" +
                "        }\n" +
                "    ]\n" +
                "}";
    }
}