DVA-C02 Deployment Practice Test 11 — 15 Questions

Question 1

A developer is using AWS Elastic Beanstalk to deploy a Python web application. The application requires a specific version of a Python package that is not pre-installed on the Elastic Beanstalk platform. How should the developer ensure the package is installed on all environment instances?

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

Accepted Answer

Add the package to a requirements.txt file and deploy it with the application source bundle.. AWS Elastic Beanstalk natively supports Python package management. If you include a `requirements.txt` file in the root directory of your source bundle, Elastic Beanstalk automatically installs the specified packages (and their specific versions, e.g., `package==1.2.3`) using `pip` during the deployment process. While `.ebextensions` can run custom commands, using it to install Python packages is non-standard, complex (due to virtual environment paths on Amazon Linux 2/2023), and unnecessary.

Answer

Use the AWS CLI to run a script on each instance after deployment.

Answer

Include a .ebextensions configuration file that runs a command to install the package.

Answer

Create a custom Dockerfile and use the Docker platform in Elastic Beanstalk.

Question 2

A development team uses AWS CodeCommit for source control and AWS CodePipeline for CI/CD. The team wants to automatically deploy changes to a staging environment when a pull request is merged into the main branch. Which CodePipeline trigger configuration should be used?

Accepted Answer

Create an Amazon CloudWatch Events rule that triggers the pipeline on a 'Reference Created' event for the main branch.. A CloudWatch Events rule for a 'Reference Created' event on the main branch triggers when a pull request is merged (a new commit is pushed to main). Option A is wrong because periodic polling is inefficient and not best practice for event-driven CI/CD. Option B is wrong because a webhook on push events triggers on every push, not specifically on pull request merge. Option D is wrong because starting the pipeline on pull request creation would trigger before the merge, not when changes are merged.

Answer

Set up a periodic polling schedule in CodePipeline to check for changes.

Answer

Configure a webhook in CodeCommit to trigger the pipeline on push events.

Answer

Use the 'Start pipeline execution' API in CodePipeline on pull request creation.

Question 3

A team uses AWS CodeBuild to run automated tests. The buildspec.yaml file contains a 'pre_build' phase that sets environment variables. During a build, the build fails with 'Error: Cannot find module 'express' when running a Node.js application. The application's package.json is in the source root. What is the most likely cause?

Accepted Answer

The buildspec does not include a command to run 'npm install' in the install or pre_build phase.. The error 'Cannot find module express' indicates that the 'express' module is not installed. In AWS CodeBuild, the buildspec specifies phases for commands. If the buildspec does not include a command like 'npm install' in the install or pre_build phase, then dependencies listed in package.json will not be installed, causing this module-not-found error. Option A is incorrect because the error message does not suggest a runtime version incompatibility; it specifically states the module cannot be found. Option B is incorrect because setting NODE_ENV to production would affect which dependencies are installed only if 'npm install' is actually run; the core issue is the absence of 'npm install'. Option D is incorrect because the error indicates the module is not found, not that package.json is missing or misplaced.

Answer

The Node.js runtime version is incompatible with the express module.

Answer

The environment variable NODE_ENV is set to production, which skips devDependencies.

Answer

The package.json file is not in the source root directory.

Question 4

A company deploys a microservices application using AWS CloudFormation. Each microservice is deployed as a separate stack. The developer wants to pass the output values (e.g., API endpoint URLs) from one stack to another. Which CloudFormation feature should be used?

Accepted Answer

Cross-stack references using Export and ImportValue. Cross-stack references using Export and Fn::ImportValue allow outputs from one CloudFormation stack to be used in another stack. Option A (Custom resources with Lambda) is incorrect because custom resources are used for custom provisioning logic, not for passing outputs between stacks. Option B (Stack outputs) is incorrect because stack outputs are not automatically accessible to other stacks without exporting them. Option C (Nested stacks) is incorrect because nested stacks are used to create hierarchical relationships, not to share outputs between independent stacks.

Answer

Custom resources with Lambda

Answer

Stack outputs

Answer

Nested stacks

Question 5

A developer is using AWS CloudFormation to deploy a stack that includes an Amazon RDS DB instance. The stack creation fails because the DB instance creation takes longer than the CloudFormation timeout. Which THREE steps can the developer take to resolve this issue? (Choose THREE.)

Accepted Answer

Increase the CloudFormation stack creation timeout.. Increasing the stack creation timeout (D) directly gives the DB instance more time. Using a custom resource with Lambda to create the DB instance asynchronously (E) decouples the DB creation from the stack timeout. A wait condition would add further delay and does not solve the underlying timeout. Therefore, only two options are correct, making the question inconsistent with its 'choose three' instruction.

Answer

Use a CloudFormation wait condition or a waiter to pause the stack creation until the DB instance is ready.

Answer

Change the DB instance class to a smaller size.

Answer

Reduce the stack creation timeout to trigger a rollback faster.

Question 6

The exhibit shows the output of the describe-stack-events command for a CloudFormation stack that failed to create. What is the most likely cause of the failure?

Accepted Answer

The Lambda function handler 'index.handler' does not exist in the deployment package.. The stack event shows CREATE_FAILED for the Lambda function resource, which is likely due to the handler 'index.handler' not being present in the deployment package. Option B is incorrect because the S3 bucket and key are correctly specified. Option C is incorrect because there is no evidence of a code size limit issue; the error points to a missing handler. Option D is incorrect because no permission errors are shown; the failure is related to the function code, not the IAM role.

Answer

The S3 bucket 'my-bucket' does not contain the object 'my-function.zip'.

Answer

The Lambda function code exceeds the maximum allowed size.

Answer

The IAM role associated with the Lambda function lacks necessary permissions.

Question 7

The exhibit shows an IAM policy attached to a user who needs to deploy applications using AWS CodeDeploy. The user reports that they cannot create a deployment for the MyApplication/MyDeploymentGroup. What is the most likely reason?

Accepted Answer

The policy does not include permission on the application resource.. The CreateDeployment action requires permission on both the application resource (arn:aws:codedeploy:region:account:application:MyApplication) and the deployment group resource. The policy only grants permission on the deployment group, not the application. Option A is wrong because the policy grants permission on the specific deployment group MyApplication/MyDeploymentGroup, not a different group. Option B is wrong because the policy includes the codedeploy:CreateDeployment action on the deployment group. Option C is wrong because the policy includes codedeploy:GetDeployment and codedeploy:GetDeploymentGroup actions.

Answer

The policy restricts the user to a different deployment group.

Answer

The user does not have permission to call the codedeploy:CreateDeployment action.

Answer

The user does not have permission to call codedeploy:GetDeployment and codedeploy:GetDeploymentGroup.

Question 8

The exhibit shows the output of the describe-instances command. An Elastic Beanstalk environment is configured to use this EC2 instance as a web server. The application is not accessible. What is the most likely cause?

Accepted Answer

The instance has been terminated.. The instance state in the exhibit is 'terminated', meaning the instance is no longer running. This makes the application inaccessible. Option B is incorrect because the security group configuration is not indicated as an issue. Option C is incorrect because the Name tag is irrelevant to accessibility. Option D is incorrect because the instance exists but is terminated.

Answer

The security group does not allow HTTP traffic.

Answer

The instance does not have the correct Name tag.

Answer

The instance does not exist.

Question 9

A developer wants to deploy a serverless application using AWS SAM. The application consists of multiple Lambda functions, an API Gateway REST API, and a DynamoDB table. The developer wants to define the application in a single template and deploy it using the AWS CLI. Which command should the developer use to package and deploy the application?

Accepted Answer

sam package and sam deploy. 'sam package' uploads the application artifacts to S3 and generates a packaged CloudFormation template, and 'sam deploy' deploys that template. Option A is incorrect because 'sam build' only builds the application locally and does not package it for deployment; while 'sam deploy' can be used after 'sam build' for local testing, the standard deployment flow for SAM is 'sam package' followed by 'sam deploy'. Option C is incorrect because although 'aws cloudformation package' and 'aws cloudformation deploy' can perform similar tasks, the question specifically asks for AWS SAM commands; SAM provides a simpler, purpose-built workflow. Option D is incorrect because 'aws s3 cp' only uploads files to S3, and 'aws cloudformation create-stack' does not handle the packaging of Lambda functions and other managed resources, leading to incomplete deployments.

Answer

sam build and sam deploy

Answer

aws cloudformation package and aws cloudformation deploy

Answer

aws s3 cp and aws cloudformation create-stack

Question 10

A company uses AWS CodeDeploy to deploy a web application to an Auto Scaling group. The deployment fails during the 'Install' lifecycle event. The developer checks the logs and finds that the scripts in the 'appspec.yml' file are not being executed because the instances are not in a healthy state. What could be the reason for the instances being unhealthy?

Accepted Answer

The health check grace period on the Auto Scaling group is too short.. If the health check grace period is too short, instances may be marked unhealthy by the Auto Scaling group before the CodeDeploy installation scripts complete. This causes the deployment to fail during the 'Install' lifecycle event. Option B is incorrect because even if the ELB is not configured to route traffic, it would not directly cause instance health check failures during deployment; it would affect traffic routing. Option C is incorrect because an outdated CodeDeploy agent might cause script execution failures, but the logs indicate scripts are not executed because instances are unhealthy, not because of agent issues. Option D is incorrect because IAM permissions affect access to artifacts, but the error is about instance health, not access denied.

Answer

The Elastic Load Balancer is not configured to route traffic to the Auto Scaling group.

Answer

The CodeDeploy agent on the instances is outdated.

Answer

The IAM instance profile does not have permissions to access the S3 bucket where the artifacts are stored.

Question 11

A developer is using AWS CodeBuild to build a Docker image and push it to Amazon ECR. The build fails with a 'no basic auth credentials' error when trying to push the image. Which TWO actions should the developer take to resolve this issue? (Choose two.)

Accepted Answer

Add a pre-build command to run 'aws ecr get-login-password --region | docker login --username AWS --password-stdin .dkr.ecr..amazonaws.com'.. The 'aws ecr get-login-password' command retrieves a temporary authentication token from AWS, which is then piped to 'docker login' to authenticate the Docker client with the Amazon ECR registry. This is the standard method for authenticating Docker to ECR, and it must be executed in the pre-build phase to ensure credentials are available before the 'docker push' command runs.

Answer

Install the AWS CLI in the buildspec.yml file.

Answer

Install Docker in the buildspec.yml file.

Answer

Configure SSH key-based authentication for ECR.

Question 12

A developer is troubleshooting a deployment failure in AWS CodePipeline. The deploy stage uses the above IAM policy for the service role. The pipeline fails when trying to update the Elastic Beanstalk environment. What is the most likely cause?

Accepted Answer

The policy restricts the UpdateEnvironment action to a specific environment ARN, but the pipeline is updating a different environment.. The IAM policy restricts the elasticbeanstalk:UpdateEnvironment action to a specific environment ARN (arn:aws:elasticbeanstalk:us-east-1:123456789012:environment/MyApp/my-env). If the pipeline is attempting to update a different environment (e.g., due to a change in environment name or region), the action will be denied, causing the deployment to fail. Option B is incorrect because DescribeEnvironmentResources is not required for updates. Option C is incorrect because the policy does not deny all actions; it only denies DeleteEnvironment. Option D is incorrect because DeleteEnvironment is not required for updates.

Answer

The policy does not allow DescribeEnvironmentResources, which is required for the deployment.

Answer

The policy denies all actions on the environment, preventing the update.

Answer

The policy denies DeleteEnvironment, which is required for the update.

Question 13

A developer is creating a deployment pipeline using AWS CodePipeline. The pipeline includes a source stage from Amazon S3, a build stage using AWS CodeBuild, and a deploy stage using AWS CloudFormation. The developer wants to ensure that the pipeline can automatically create the CloudFormation stack if it does not exist. Which action mode should the developer use in the CloudFormation deploy action?

Accepted Answer

CREATE_UPDATE. The 'CREATE_UPDATE' action mode creates a new stack if it does not exist or updates it if it does. Option A is incorrect because 'UPDATE_ONLY' only updates an existing stack and fails if the stack does not exist. Option C is incorrect because 'REPLACE_ON_FAILURE' replaces a failed stack but does not create a new one if it doesn't exist. Option D is incorrect because 'CREATE_ONLY' only creates a stack if it does not exist, but it will not update an existing stack.

Answer

UPDATE_ONLY

Answer

REPLACE_ON_FAILURE

Answer

CREATE_ONLY

Question 14

A company uses AWS Elastic Beanstalk to deploy a web application. The developer wants to perform a blue/green deployment to minimize downtime. The developer creates a new environment and deploys the new version. After verifying the new environment is healthy, the developer needs to swap the URLs so that traffic is routed to the new environment. Which AWS Elastic Beanstalk feature should the developer use?

Accepted Answer

Use the 'Swap environment URLs' feature in the Elastic Beanstalk console.. Use the 'Swap environment URLs' feature in the Elastic Beanstalk console. This feature swaps the CNAME records between two environments, allowing you to route traffic to the new, healthy environment with minimal downtime. Option B is not recommended because deleting the old environment before fully verifying the new one is risky. Option C involves Route 53 weighted routing, which is not an Elastic Beanstalk feature and requires manual DNS management outside of Elastic Beanstalk. Option D is incorrect because environment CNAMEs are managed by Elastic Beanstalk and cannot be changed manually.

Answer

Delete the old environment and update the DNS record to point to the new environment.

Answer

Use Amazon Route 53 weighted routing policies to shift traffic.

Answer

Change the environment's CNAME to point to the new environment.

Question 15

A developer is deploying a serverless application using AWS SAM. The developer wants to run integration tests against the deployed API Gateway endpoints before promoting the deployment to production. The developer uses AWS CodePipeline with a canary deployment strategy. How can the developer implement testing in the pipeline?

Accepted Answer

Add a Lambda function as a test action in CodePipeline that runs after the deploy stage and before the final promote.. CodePipeline allows a Lambda function to be invoked as a custom test action after the deploy stage. This enables running integration tests against the canary deployment (the new version with a small percentage of traffic) before the promote stage fully shifts traffic to the new version. Option A is wrong because manual testing defeats automation and is not part of the pipeline. Option C is wrong because API Gateway stage variables are used to route traffic based on stage, not for canary testing within a pipeline; the canary deployment is managed by CodePipeline's canary strategy. Option D is wrong because CodeBuild is primarily for build and unit tests, not for post-deployment integration testing in a canary scenario.

Answer

Use AWS CloudFormation stack outputs to get the endpoint URL and manually test.

Answer

Use API Gateway stage variables to route a percentage of traffic to the new version and monitor.

Answer

Configure CodeBuild to run tests after deployment.