The answer is to create a service role for CodeBuild with an IAM policy that grants ECR pull access. This is the most secure approach because CodeBuild assumes this role at build time, inheriting only the specific permissions needed to pull Docker images from the private repository, without requiring long-term credentials or manual token management. On the AWS Certified DevOps Engineer Professional DOP-C02 exam, this concept tests your understanding of least-privilege IAM roles versus alternative methods like storing access keys or using authorization tokens, which introduce security risks or operational overhead. A common trap is assuming VPC endpoints alone grant access—they only enable private network connectivity, but IAM permissions are still mandatory. Remember the memory tip: "Role, not token" — always prefer an IAM role passed in the build project configuration over any credential-based solution for granting CodeBuild access to ECR.
DOP-C02 Security and Compliance Practice Question
This DOP-C02 practice question tests your understanding of security and compliance. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A company is using AWS CodeBuild as part of its CI/CD pipeline. The build projects need to access a private Amazon ECR repository to pull Docker images. What is the MOST secure way to grant CodeBuild access to ECR?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Create a service role for CodeBuild with an IAM policy that grants ECR pull access.
Option A is correct because CodeBuild can assume an IAM role with ECR permissions, and the role is passed in the build project configuration. Option B is wrong because storing credentials is insecure. Option C is wrong because ECR authorization tokens can be used but require handling credentials. Option D is wrong because VPC endpoints do not grant access; IAM permissions are still needed.
Key principle: Authentication proves identity; authorization controls what that identity can do after login. Both must work for full privileged access.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
Configure a VPC endpoint for ECR and allow CodeBuild to connect through it.
Why it's wrong here
VPC endpoints provide private connectivity but do not grant permissions.
✗
Store ECR credentials in AWS Systems Manager Parameter Store and retrieve them in the buildspec.
Why it's wrong here
Storing credentials is less secure than using IAM roles.
✓
Create a service role for CodeBuild with an IAM policy that grants ECR pull access.
Why this is correct
CodeBuild assumes the service role to access ECR.
Related concept
Authentication checks who the user is.
✗
Use the AWS CLI to retrieve an ECR authorization token and pass it to Docker.
Why it's wrong here
Requires managing temporary credentials.
Common exam traps
Common exam trap: authentication is not authorization
Logging in proves the user can authenticate. It does not automatically mean the user is allowed to enter privileged or configuration mode. Watch for AAA authorization, privilege level and command authorization details.
Detailed technical explanation
How to think about this question
This kind of question is testing the difference between identity and permission. A user may successfully log in to a router because authentication is working, but still fail to enter configuration mode because authorization is missing, misconfigured or mapped to a lower privilege level.
KKey Concepts to Remember
Authentication checks who the user is.
Authorization controls what the user is allowed to do after login.
Privilege levels affect access to EXEC and configuration commands.
AAA, TACACS+ and RADIUS can separate login success from command access.
TExam Day Tips
→Do not assume successful login means full administrative access.
→Look for words such as cannot enter configuration mode, privilege level, authorization or command access.
→Separate login problems from permission problems before choosing the answer.
Key takeaway
Authentication proves identity; authorization controls what that identity can do after login. Both must work for full privileged access.
Real-world example
How this comes up in practice
A company's IT admin needs to give a contractor read-only access to production logs without sharing account credentials. Using role-based access control (RBAC) and temporary scoped permissions — not a permanent shared password — is the correct pattern. Questions like this test whether you can apply least-privilege access across cloud identity services.
What to study next
Got this wrong? Here's your next step.
Review Cisco AAA concepts — authentication, authorization, and accounting. Study privilege levels (0–15), command authorization under TACACS+, and how RADIUS differs. Then practise related DOP-C02 questions on access control and AAA configuration.
Security and Compliance — This question tests Security and Compliance — Authentication checks who the user is..
What is the correct answer to this question?
The correct answer is: Create a service role for CodeBuild with an IAM policy that grants ECR pull access. — Option A is correct because CodeBuild can assume an IAM role with ECR permissions, and the role is passed in the build project configuration. Option B is wrong because storing credentials is insecure. Option C is wrong because ECR authorization tokens can be used but require handling credentials. Option D is wrong because VPC endpoints do not grant access; IAM permissions are still needed.
What should I do if I get this DOP-C02 question wrong?
Review Cisco AAA concepts — authentication, authorization, and accounting. Study privilege levels (0–15), command authorization under TACACS+, and how RADIUS differs. Then practise related DOP-C02 questions on access control and AAA configuration.
What is the key concept behind this question?
Authentication checks who the user is.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A DevOps engineer is troubleshooting a failed AWS CodeBuild project. The build fails with an error indicating that the IAM role does not have permission to describe Amazon ECR repositories. The role used by CodeBuild has the following policy attached: {"Version":"2012-10-17","Statement":[{"Effect":"Allow","Action":["ecr:GetAuthorizationToken","ecr:BatchCheckLayerAvailability","ecr:GetDownloadUrlForLayer","ecr:BatchGetImage"],"Resource":"*"}]}. What is the missing permission?
hard
A.ecr:InitiateLayerUpload
B.ecr:GetRepositoryPolicy
C.ecr:ListImages
✓ D.ecr:DescribeRepositories
Why D: The policy allows several ECR actions but does not include 'ecr:DescribeRepositories'. The error specifically mentions 'describe' which is that action. The other actions are present.
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This DOP-C02 practice question is part of Courseiva's free Amazon Web Services certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the DOP-C02 exam.
Question Discussion
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