4.3.1. Sample Questions - Domain 1: SDLC Automation

Question 1:

A development team is using AWS CodePipeline to automate their CI/CD process. They need to ensure that every code change is automatically built, tested, and deployed to a staging environment. Which combination of AWS services should be integrated into CodePipeline to achieve this, adhering to DevOps best practices for automation and feedback?

A) AWS CodeCommit, AWS CodeBuild, AWS CodeDeploy B) Amazon S3, AWS Lambda, Amazon EC2 C) AWS CloudFormation, AWS Systems Manager, Amazon DynamoDB D) Amazon SQS, AWS Step Functions, Amazon SNS

Correct Answer: A

Explanation:

• A) AWS CodeCommit, AWS CodeBuild, AWS CodeDeploy: This combination represents the core services for a robust CI/CD pipeline on AWS. CodeCommit provides version control for source code, CodeBuild compiles code and runs tests, and CodeDeploy automates deployments to various compute services. This aligns with the First Principle of Automation across the SDLC.
• B) Amazon S3, AWS Lambda, Amazon EC2: While these services can be part of a deployment, they don't inherently form a complete CI/CD pipeline. S3 is for storage, Lambda for serverless compute, and EC2 for virtual servers. They lack the integrated orchestration and build/deploy capabilities of the Code* services.
• C) AWS CloudFormation, AWS Systems Manager, Amazon DynamoDB: These services are primarily for Infrastructure as Code (CloudFormation), operational management (Systems Manager), and NoSQL databases (DynamoDB). They are not the primary tools for orchestrating a software delivery pipeline.
• D) Amazon SQS, AWS Step Functions, Amazon SNS: These are messaging and workflow orchestration services. While useful for event-driven architectures, they are not designed for the core build and deployment phases of a CI/CD pipeline.

Question 2:

A DevOps engineer needs to implement a strategy to minimize downtime during application deployments to an Amazon EC2 Auto Scaling group. The solution must allow for quick rollback in case of issues and ensure that the new version is thoroughly tested before fully replacing the old one. Which deployment strategy best meets these requirements?

A) In-place deployment B) Blue/Green deployment C) Rolling update D) All-at-once deployment

Correct Answer: B

Explanation:

• A) In-place deployment: This strategy updates applications directly on existing instances, leading to downtime and higher risk during rollback. It violates the First Principle of Minimizing Risk and Ensuring Availability during deployments.
• B) Blue/Green deployment: This strategy involves deploying the new application version (Green environment) alongside the current production version (Blue environment). Traffic is then shifted to the Green environment. If issues arise, traffic can be quickly reverted to the Blue environment, minimizing downtime and enabling rapid rollback. This aligns with the First Principle of High Availability and Rapid Recovery.
• C) Rolling update: This strategy updates instances in batches, gradually replacing the old version with the new. While it reduces downtime compared to in-place, rollback can be more complex and slower than Blue/Green.
• D) All-at-once deployment: This strategy deploys the new version to all instances simultaneously, which is high-risk and does not allow for gradual rollout or early issue detection. It directly contradicts the First Principle of Ensuring Availability.

Question 3:

A company wants to automate the creation and management of container images for their microservices. They need a solution that integrates with their CI/CD pipeline and ensures that images are built consistently and securely. Which AWS service is specifically designed for this purpose?

A) Amazon S3 B) AWS CodeArtifact C) Amazon ECR D) EC2 Image Builder

Correct Answer: D

Explanation:

• A) Amazon S3: S3 is an object storage service, not designed for building or managing container images. While images might be stored in S3, it's not the build tool.
• B) AWS CodeArtifact: CodeArtifact is a fully managed artifact repository service that makes it easy for organizations to securely store, publish, and share software packages. It's for packages, not for building container images.
• C) Amazon ECR (Elastic Container Registry): ECR is a fully managed Docker container registry that makes it easy to store, manage, and deploy Docker container images. It's a repository for images, not a builder.
• D) EC2 Image Builder: EC2 Image Builder is a fully managed AWS service that makes it easier to automate the creation, management, and deployment of customized, secure, and up-to-date server images. This includes both EC2 AMIs and container images. It directly addresses the need for automated and consistent image building, aligning with the First Principle of Automation and Consistency in image management.

Question 4:

A DevOps team is using AWS CodeBuild to run automated tests as part of their CI pipeline. They need to ensure that sensitive API keys required by the tests are securely accessed during the build process without hardcoding them into the buildspec.yml or source code. Which AWS service should they use to manage and retrieve these secrets?

A) AWS CloudTrail B) AWS Key Management Service (KMS) C) AWS Secrets Manager D) Amazon GuardDuty

Correct Answer: C

Explanation:

• A) AWS CloudTrail: CloudTrail records API calls and related events in your AWS account. It's for auditing, not for managing secrets.
• B) AWS Key Management Service (KMS): KMS is a service that makes it easy for you to create and manage cryptographic keys and control their use across a wide range of AWS services and in your applications. While KMS can encrypt secrets, Secrets Manager is the dedicated service for managing and retrieving them.
• C) AWS Secrets Manager: Secrets Manager helps you protect access to your applications, services, and IT resources by enabling you to easily rotate, manage, and retrieve database credentials, API keys, and other secrets throughout their lifecycle. It integrates directly with CodeBuild to securely inject secrets into the build environment, adhering to the First Principle of Least Privilege and Secure Credential Management.
• D) Amazon GuardDuty: GuardDuty is a threat detection service that continuously monitors for malicious activity and unauthorized behavior to protect your AWS accounts and workloads. It's for security monitoring, not secrets management.

Question 5:

A company is adopting a microservices architecture and needs to ensure that each service can be deployed independently and reliably. They are looking for a deployment methodology that allows for gradual rollout of new features to a small subset of users before a full production release, enabling early detection of issues with minimal impact. Which deployment strategy is most suitable for this requirement?

A) Rolling update B) All-at-once deployment C) Canary deployment D) Blue/Green deployment

Correct Answer: C

Explanation:

• A) Rolling update: While rolling updates deploy in batches, they don't inherently provide the fine-grained control over traffic distribution to a small subset of users for early testing that a canary deployment offers.
• B) All-at-once deployment: This deploys to all instances simultaneously, which is high-risk and does not allow for gradual rollout or early issue detection. It violates the First Principle of Minimizing Blast Radius.
• C) Canary deployment: This strategy involves releasing a new version of an application or service to a small subset of users (the "canary group") to test its stability and performance in a real production environment. If the canary performs well, the new version is gradually rolled out to the rest of the users. This aligns with the First Principle of Progressive Delivery and Risk Mitigation by limiting the impact of potential issues.
• D) Blue/Green deployment: This strategy involves running two identical production environments. While it allows for quick rollback, it typically involves a full traffic switch, not a gradual rollout to a small subset of users for testing.