DOP-C02 SDLC Automation Practice Test 22 — 15 Questions

Question 1

A development team uses AWS CodeCommit as a Git repository. They want to automatically trigger a build in AWS CodeBuild whenever a pull request is created or updated. Which AWS service should be used to detect the pull request events and start the build?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Amazon EventBridge. Amazon EventBridge can capture CodeCommit repository events, such as pull request creation and updates, via its event bus. By setting up an EventBridge rule that matches these specific events, you can directly trigger an AWS CodeBuild project as a target, enabling automated builds without additional orchestration services.

Answer

Amazon Simple Notification Service (SNS)

Answer

AWS CodePipeline

Answer

Amazon CloudWatch Logs

Question 2

A DevOps engineer is designing a CI/CD pipeline for a microservices application using AWS CodePipeline. Each microservice has its own CodeCommit repository. The engineer wants to run unit tests in parallel for all services when any repository receives a push, then run integration tests only after all unit tests pass. Which pipeline structure should the engineer use?

Accepted Answer

Create a single pipeline with a parallel action for unit tests, then a serial stage for integration tests. AWS CodePipeline supports parallel actions within a stage, allowing unit tests for all microservices to run concurrently. After all unit tests succeed, the pipeline transitions to a serial stage for integration tests, ensuring the correct dependency order. This structure minimizes build time while enforcing the required sequential gate.

Answer

Create a single pipeline with a serial stage for unit tests, then integration tests

Answer

Create one pipeline per microservice, each triggering integration tests via SNS

Answer

Use AWS CodeBuild batch builds with a fan-out/fan-in pattern

Question 3

A company uses AWS CodeDeploy to deploy a web application to an Auto Scaling group. The deployment fails during the 'ValidateService' lifecycle event. The CloudWatch Agent reports that the target process is running but the health check endpoint returns HTTP 503. The CodeDeploy agent logs show no errors. What is the most likely cause of the failure?

Accepted Answer

The application is not fully functional due to missing configuration files. The 'ValidateService' lifecycle event in CodeDeploy runs a health check against the application endpoint. A 503 HTTP status indicates the web server is running (the target process is up) but the application itself is not fully functional, often due to missing configuration files, environment variables, or dependencies. The CloudWatch Agent confirming the process is running and the CodeDeploy agent logs showing no errors further isolate the issue to the application layer, not the deployment infrastructure.

Answer

The Auto Scaling group is not healthy

Answer

The CodeDeploy agent is not installed on the instances

Answer

The target process is not listening on the expected port

Question 4

A DevOps team uses AWS CodePipeline to deploy a static website to Amazon S3. The pipeline has a source stage from CodeCommit, a build stage using CodeBuild that generates the website files, and a deploy stage that copies files to an S3 bucket. The team wants to add a manual approval step before the deploy stage. What should the engineer do?

Accepted Answer

Add an approval action in the pipeline stage before deploy. AWS CodePipeline natively supports a manual approval action that can be added as a stage gate. By inserting an approval action in a stage immediately before the deploy stage, the pipeline will pause and require a designated approver to manually approve or reject the deployment, ensuring human oversight before files are copied to the S3 bucket.

Answer

Use Amazon SNS to send a notification and rely on a Lambda function to resume

Answer

Add a CodeBuild action that waits for an SNS confirmation

Answer

Configure the S3 bucket to send an event to the pipeline after upload

Question 5

A DevOps engineer is troubleshooting a slow AWS CodeBuild project. The build is a Java application that compiles source code and runs tests. The build environment uses a general1.large compute type. The build duration has increased from 5 minutes to 15 minutes over the past month. The engineer notices that the build logs show 'Downloading...' messages for Maven dependencies for several minutes. What is the most cost-effective way to reduce the build time?

Accepted Answer

Enable local caching in the CodeBuild project for dependencies. Enabling local caching in AWS CodeBuild allows the build environment to cache Maven dependencies in the local file system across builds. This eliminates the need to re-download dependencies from remote repositories each time, directly addressing the 'Downloading...' messages in the logs. It is the most cost-effective solution as it requires no additional AWS services or compute upgrades.

Answer

Configure the build to use a VPC with a NAT gateway

Answer

Use AWS CodeArtifact as a proxy for Maven dependencies

Answer

Change the compute type to general1.2xlarge

Question 6

A company uses AWS CodeDeploy with a blue/green deployment configuration. The engineer wants to automatically roll back the deployment if the new instances fail the health check for 5 minutes. Which setting should the engineer configure?

Accepted Answer

Configure the deployment group to roll back when a CloudWatch alarm is triggered. AWS CodeDeploy blue/green deployments can be configured to automatically roll back when a CloudWatch alarm is triggered. By creating a CloudWatch alarm that monitors the health check endpoint and associating it with the deployment group, the engineer can ensure that if the alarm state persists for 5 minutes (as defined in the alarm's period and evaluation periods), CodeDeploy will automatically initiate a rollback to the previous working version.

Answer

Create a CloudWatch alarm that monitors the health check endpoint

Answer

Set the Auto Scaling group health check grace period to 5 minutes

Answer

Set the deployment configuration's 'timeout' to 5 minutes

Question 7

A company uses AWS CodePipeline with an Amazon S3 source action. The pipeline deploys to an Amazon ECS Fargate service. The engineer notices that the pipeline does not automatically start when a new object is uploaded to the S3 bucket. The S3 bucket versioning is enabled. What is the most likely cause?

Accepted Answer

The S3 bucket does not have event notifications configured for the pipeline. AWS CodePipeline with an S3 source action does not automatically detect new object uploads unless the S3 bucket is configured with event notifications that trigger the pipeline. Without these notifications, the pipeline must be started manually or via a webhook. Since versioning is enabled, the issue is not related to versioning but to the missing event notification configuration.

Answer

The pipeline has manual approval required before the source stage

Answer

S3 versioning is not enabled on the bucket

Answer

The ECS service is not configured for blue/green deployments

Question 8

A DevOps engineer is designing a CI/CD pipeline for a containerized application using AWS CodeBuild and Amazon ECS. Which TWO actions will help reduce the frequency of Docker image pulls from the public Docker Hub registry?

Accepted Answer

Enable CodeBuild local caching for the cache type 'LOCAL_DOCKER_LAYER_CACHE'. Option B is correct because enabling CodeBuild local caching with the cache type 'LOCAL_DOCKER_LAYER_CACHE' persists Docker image layers between builds on the same host, so previously pulled base image layers are reused and Docker does not need to re-pull them from Docker Hub. Option C is correct because storing the base image in Amazon ECR and referencing it in the build pulls the image from ECR (a private, AWS-hosted registry) instead of the public Docker Hub registry, directly reducing Docker Hub pulls. Option A is incorrect because a Docker Hub access token in Secrets Manager only authenticates and raises rate limits; it does not reduce the number or frequency of image pulls. Option D is incorrect because AWS CodeArtifact does not support Docker/OCI registries as a Docker Hub proxy (it supports package formats like npm, Maven, PyPI, NuGet), so it cannot serve as a pull-through cache for Docker images. Option E is incorrect because attaching CodeBuild to a VPC with a NAT gateway only changes network routing for outbound traffic; it does not cache or eliminate Docker Hub image pulls.

Answer

Create a Docker Hub access token and store it in AWS Secrets Manager

Answer

Use AWS CodeArtifact as a proxy for Docker Hub

Answer

Configure CodeBuild to use a VPC with a NAT gateway

Question 9

Refer to the exhibit. A DevOps engineer runs the above commands. The build project 'my-project' uses an S3 bucket as source and another S3 bucket for artifacts. The build fails with an 'Access Denied' error when trying to download the source code. What is the most likely cause?

Accepted Answer

The service role does not have s3:GetObject permission on the source bucket. The build project 'my-project' uses an S3 bucket as the source. When CodeBuild downloads source code from S3, the service role must have the s3:GetObject permission on the source bucket. The 'Access Denied' error indicates that the role lacks this permission, making option B the most likely cause.

Answer

The encryption key is a KMS key that the role cannot access

Answer

The source type is S3, but the project expects CodeCommit

Answer

The source location is incorrect

Question 10

Refer to the exhibit. A DevOps engineer deploys this CloudFormation template. The EC2 instance launches, but the httpd service does not start. The engineer connects to the instance and finds that the user data script did not run. What is the most likely cause?

Accepted Answer

The AMI does not have yum installed. The most likely cause is that the AMI does not have yum installed. The CloudFormation template's UserData script uses yum to install httpd, but if the AMI is based on a distribution that does not use yum (e.g., Amazon Linux 2023 uses dnf, or Ubuntu uses apt), the script will fail silently or not execute as intended. Since the script itself is valid and the instance launched, the failure is due to the package manager not being available, preventing the httpd service from starting.

Answer

The UserData is not base64 encoded correctly

Answer

The tags prevent user data from executing

Answer

The AMI uses a different init system than systemd

Question 11

A development team uses AWS CodeCommit as a Git repository. They want to automatically trigger a build in AWS CodeBuild whenever a pull request is created or updated. Which AWS service should be used to detect the pull request events and start the build?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Use Amazon CloudWatch Events to trigger the pipeline on a CodeCommit 'Reference Created' event.. AWS CodePipeline can be configured to start execution automatically when a new branch is created in CodeCommit by using Amazon CloudWatch Events (now part of Amazon EventBridge) to listen for the 'Reference Created' event type. This event is emitted by CodeCommit whenever a new Git reference (such as a branch or tag) is created, and it can directly target a CodePipeline pipeline as a rule target, triggering a new execution without any custom polling or webhook setup.

Answer

Create an S3 event notification to invoke the pipeline when a branch is created.

Answer

Configure a webhook in CodePipeline to detect branch creation events.

Answer

Set up a polling mechanism in CodePipeline to check for new branches every minute.

Question 12

A team uses AWS CodeDeploy to deploy a web application to an Auto Scaling group. The deployment fails with the error 'The overall deployment failed because too many individual instances failed deployment, too few healthy instances are available, or some instances in your deployment group are experiencing problems.' The team checks the logs and finds that the application installation script fails on some instances due to missing dependencies. What is the BEST long-term solution?

Accepted Answer

Create a custom AMI that includes all dependencies and use it in the Auto Scaling group.. Creating a custom AMI that includes all dependencies ensures that every instance launched in the Auto Scaling group has the required software pre-installed. This eliminates the root cause of the deployment failure—missing dependencies—by baking them into the machine image, making deployments consistent and reliable. It is the best long-term solution because it avoids runtime dependency installation failures and reduces deployment time.

Answer

Use an Elastic Load Balancer health check to automatically replace failed instances.

Answer

Modify the CodeDeploy AppSpec file to run the installation script as root.

Answer

Implement a retry mechanism in the deployment script to install dependencies again.

Question 13

A company has a monorepo in AWS CodeCommit with multiple microservices. They want to use AWS CodePipeline to build and deploy only the microservice that changed. What is the MOST efficient approach?

Accepted Answer

Use an AWS Lambda function triggered by CloudWatch Events for CodeCommit to start the specific pipeline for the changed microservice.. It uses an AWS Lambda function triggered by CloudWatch Events (now Amazon EventBridge) on CodeCommit repository events (e.g., push to a specific branch) to detect which microservice changed and then start the corresponding CodePipeline pipeline. This is the most efficient approach as it avoids unnecessary builds of unchanged microservices and does not require splitting the monorepo or adding complex conditional logic within a single pipeline.

Answer

Configure a single pipeline that always builds all microservices.

Answer

Create separate CodeCommit repositories for each microservice.

Answer

Use a single pipeline with multiple build actions that each check if their microservice changed.

Question 14

A DevOps engineer needs to automate the creation of a CI/CD pipeline using infrastructure as code. Which AWS service is BEST suited to define and provision the pipeline resources?

Accepted Answer

AWS CloudFormation. AWS CloudFormation is the correct choice because it is an infrastructure-as-code (IaC) service that allows you to define and provision AWS resources, including CI/CD pipeline components like CodePipeline, CodeBuild, and CodeDeploy, using declarative templates. This enables fully automated, repeatable, and version-controlled pipeline creation without manual intervention.

Answer

AWS Elastic Beanstalk

Answer

AWS CodePipeline

Answer

AWS Service Catalog

Question 15

An organization uses AWS CodePipeline with multiple stages: Source, Build, Test, and Deploy. The Test stage runs integration tests that take 30 minutes. The team wants to speed up feedback without skipping tests. Which action should they take?

Accepted Answer

Configure parallel build actions in the Test stage to run tests concurrently.. Running integration tests in parallel within the Test stage reduces the total wall-clock time for the test suite, speeding up feedback without skipping any tests. AWS CodePipeline supports parallel actions within a stage, allowing multiple test suites to execute concurrently, which directly addresses the goal of faster feedback while maintaining test coverage.

Answer

Use a larger build environment for the Test stage.

Answer

Remove the Test stage and rely on post-deployment testing.

Answer

Move the Test stage to after deployment.