Jeff’s Note #
Unlike generic exam dumps, ADH analyzes this scenario through the lens of a Real-World Lead Developer.
For DVA-C02 candidates, the confusion often lies in knowing which AWS CLI command actually tests IAM role permissions without changing anything, versus commands that modify permissions or manage sessions. In production, this is about understanding exactly how to simulate or verify role assumptions and associated permissions from the CLI to debug access problems effectively. Let’s drill down.
The Certification Drill (Simulated Question) #
Scenario #
GammaSoft Technologies is developing a serverless application that modifies records in an Amazon RDS database cluster. The application assumes an IAM role to obtain necessary permissions. A lead developer on the team needs to validate whether the IAM role assigned to the application has the correct permissions before deploying the code to production. The developer currently has access to the IAM role but wants to test the role permissions from their local workstation using AWS CLI commands.
The Requirement: #
Determine which AWS CLI command will allow the developer to validate the permissions associated with the IAM role the application uses, without making any state changes or attaching new policies.
The Options #
- A)
aws sts assume-role - B)
aws iam attach-role-policy - C)
aws ssm resume-session - D)
aws rds add-role-to-db-cluster
Google adsense #
leave a comment:
Correct Answer #
A) aws sts assume-role
Quick Insight: The Developer’s Imperative #
Understanding how to assume an IAM role using the AWS Security Token Service (STS) lets you verify that your AWS credentials can successfully obtain temporary access with that role. This is the fundamental step to test if the role’s trust and permission policies allow your current identity to use it—without altering permissions or resources. The other commands either modify policies, manage sessions unrelated to IAM role assumption, or assign roles to RDS clusters, which is beyond permission testing.
Content Locked: The Expert Analysis #
You’ve identified the answer. But do you know the implementation details that separate a Junior from a Senior?
The Expert’s Analysis #
Correct Answer #
Option A: aws sts assume-role
The Winning Logic #
The aws sts assume-role command initiates a call that requests temporary security credentials for the specified IAM role. This command simulates what the application does under the hood—assuming the role to get permissions attached to it. If the call succeeds, it confirms that the role’s trust policy allows assuming the role and that the caller has permission. This is the closest you can get to testing the IAM role permissions without actually making any modifications or attaching policies.
The Trap (Distractor Analysis): #
- Why not B (
aws iam attach-role-policy)?
This command actually attaches a policy to an IAM role; it modifies permissions instead of testing them. Using it to “test” role permissions is wrong and dangerous. - Why not C (
aws ssm resume-session)?
This command resumes an AWS Systems Manager session to a managed instance—completely unrelated to IAM role permission testing. - Why not D (
aws rds add-role-to-db-cluster)?
This attaches an IAM role to an RDS DB cluster, altering resource configuration rather than testing permissions.
The Technical Blueprint #
# Example: Using sts assume-role to test permissions of an IAM role named "MyAppRole"
aws sts assume-role --role-arn arn:aws:iam::123456789012:role/MyAppRole --role-session-name TestSession
If this command returns temporary credentials successfully, the role’s trust and permission policies are valid for your caller identity.
The Comparative Analysis #
| Option | AWS CLI Command | Purpose | Usage for Permission Testing | Comments |
|---|---|---|---|---|
| A | aws sts assume-role |
Assume IAM role to get temp creds | Yes | Correct way to test role assumption and permissions |
| B | aws iam attach-role-policy |
Attach policy to IAM role | No | Changes permissions, not a test |
| C | aws ssm resume-session |
Resume SSM session | No | No relevance to IAM role testing |
| D | aws rds add-role-to-db-cluster |
Attach role to RDS instance | No | Alters DB cluster resource setup |
Real-World Application (Practitioner Insight) #
Exam Rule #
For the exam, always pick aws sts assume-role when you see the keyword “test IAM role permissions” in a developer context without modifying anything.
Real World #
In reality, developers may use SDK commands or embedded IAM role assumption inside their apps, but verifying with aws sts assume-role CLI calls locally is a fast and reliable troubleshooting technique before deployment.
(CTA) Stop Guessing, Start Mastering #
Disclaimer
This is a study note based on simulated scenarios for the AWS DVA-C02 exam.