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Demystifying InvalidResourceException in AWS Shield

Posted Updated
By Exception Decoded 3 min read

Introduction

As the prevalence of cyber threats continues to rise, organizations are seeking robust security measures to shield their applications and resources. AWS Shield, a managed Distributed Denial of Service (DDoS) protection service, provides enhanced security to your applications running in the AWS Cloud. One common exception encountered while working with AWS Shield is the InvalidResourceException. In this article, we will explore the InvalidResourceException in detail, understand its causes, and provide effective solutions to overcome this exception.

Understanding the InvalidResourceException

The InvalidResourceException is an exception class defined in the com.amazonaws.services.shield.model package of AWS SDK. This exception occurs when an invalid resource is specified during an API call to AWS Shield.

Causes of InvalidResourceException

There can be several reasons that trigger the InvalidResourceException. Let’s explore a few common scenarios:

  1. Incorrect ARN (Amazon Resource Names): When making API calls to AWS Shield, it’s crucial to ensure that the ARN provided for the resource is correct. The service uses ARNs to uniquely identify AWS resources. If an incorrect ARN is specified, the InvalidResourceException is thrown.

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     import com.amazonaws.services.shield.AWSShield;
 import com.amazonaws.services.shield.model.*;
    
 public class ShieldResourceUtil {
        
     public void enableShieldProtection(String resourceArn) {
         AWSShield shieldClient = AWSShieldClientBuilder.defaultClient();
         EnableProtectionRequest enableProtectionRequest = new EnableProtectionRequest()
                 .setResourceArn(resourceArn);
                    
         try {
             shieldClient.enableProtection(enableProtectionRequest);
         } catch (InvalidResourceException e) {
             System.out.println("InvalidResourceException: " + e.getMessage());
         }
     }
 }

  2. Resource not eligible for protection: AWS Shield offers protection primarily against DDoS attacks. However, not all AWS resources are eligible for protection. For instance, AWS Shield only provides protection for Elastic Load Balancers (ELB), Amazon CloudFront, and Amazon Route 53 resources. If you attempt to enable protection for an ineligible resource, the InvalidResourceException is thrown.

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     import com.amazonaws.services.shield.AWSShield;
 import com.amazonaws.services.shield.model.*;
    
 public class ShieldResourceUtil {
        
     public void enableShieldProtection(String resourceArn) {
         AWSShield shieldClient = AWSShieldClientBuilder.defaultClient();
         EnableProtectionRequest enableProtectionRequest = new EnableProtectionRequest()
                 .setResourceArn(resourceArn);
                    
         try {
             shieldClient.enableProtection(enableProtectionRequest);
         } catch (InvalidResourceException e) {
             System.out.println("InvalidResourceException: " + e.getMessage());
         }
     }
 }

  3. Resource already protected: AWS Shield allows enabling protection only on eligible resources once per AWS account. If you attempt to enable protection on an already protected resource, the service throws the InvalidResourceException.

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     import com.amazonaws.services.shield.AWSShield;
 import com.amazonaws.services.shield.model.*;
    
 public class ShieldResourceUtil {
        
     public void enableShieldProtection(String resourceArn) {
         AWSShield shieldClient = AWSShieldClientBuilder.defaultClient();
         EnableProtectionRequest enableProtectionRequest = new EnableProtectionRequest()
                 .setResourceArn(resourceArn);
                    
         try {
             shieldClient.enableProtection(enableProtectionRequest);
         } catch (InvalidResourceException e) {
             System.out.println("InvalidResourceException: " + e.getMessage());
         }
     }
 }

Overcoming the InvalidResourceException

While encountering the InvalidResourceException can be daunting, there are ways to overcome it effectively. Let’s explore a few strategies:

  1. Verify the ARN: When facing an InvalidResourceException, it’s essential to double-check the ARN provided for the resource. Ensure that the ARN is accurate and matches the intended resource. You can find the correct ARN format in the AWS Shield documentation.

  2. Check resource eligibility for protection: Before attempting to enable protection for a resource, verify if the resource is eligible for AWS Shield protection. Refer to the AWS documentation to understand which resources are supported by AWS Shield. Attempting to enable protection on an ineligible resource will result in the InvalidResourceException.

  3. Ensure resource protection status: When calling the enableProtection API, it’s important to check the protection status of the resource beforehand. You can use the GetProtectionStatus API to determine if the resource is already protected. This will help prevent the InvalidResourceException caused by attempting to enable protection on an already protected resource.

Conclusion

Effectively handling exceptions is an important aspect of application development. In this article, we explored the InvalidResourceException in the context of AWS Shield. We discussed the causes of this exception, including incorrect ARN usage, ineligible resources, and already protected resources. Furthermore, we provided effective strategies to overcome the InvalidResourceException. By following these best practices, you can ensure smooth error handling and effectively protect your resources from DDoS attacks using AWS Shield.

For more information on AWS Shield and exception handling, please refer to the official documentation:

Thank you for reading this article. Stay vigilant, stay secure!

AWS, AWS Shield
aws shield com.amazonaws.services.shield.model
This post is licensed under CC BY 4.0 by the author.