DOP-C01 : AWS DevOps Engineer Professional : Part 01

DOP-C01 : AWS DevOps Engineer Professional : Part 01

1. To run an application, a DevOps Engineer launches an Amazon EC2 instances with public IP addresses in a public subnet. A user data script obtains the application artifacts and installs them on the instances upon launch. A change to the security classification of the application now requires the instances to run with no access to the Internet. While the instances launch successfully and show as healthy, the application does not seem to be installed.

   Which of the following should successfully install the application while complying with the new rule?

   • Launch the instances in a public subnet with Elastic IP addresses attached. Once the application is installed and running, run a script to disassociate the Elastic IP addresses afterwards.
   • Set up a NAT gateway. Deploy the EC2 instances to a private subnet. Update the private subnet’s route table to use the NAT gateway as the default route.
   • Publish the application artifacts to an Amazon S3 bucket and create a VPC endpoint for S3. Assign an IAM instance profile to the EC2 instances so they can read the application artifacts from the S3 bucket.
   • Create a security group for the application instances and whitelist only outbound traffic to the artifact repository. Remove the security group rule once the install is complete.

2. An IT department manages a portfolio with Windows and Linux (Amazon and Red Hat Enterprise Linux) servers both on-premises and on AWS. An audit reveals that there is no process for updating OS and core application patches, and that the servers have inconsistent patch levels.

   Which of the following provides the MOST reliable and consistent mechanism for updating and maintaining all servers at the recent OS and core application patch levels?

   • Install AWS Systems Manager agent on all on-premises and AWS servers. Create Systems Manager Resource Groups. Use Systems Manager Patch Manager with a preconfigured patch baseline to run scheduled patch updates during maintenance windows.
   • Install the AWS OpsWorks agent on all on-premises and AWS servers. Create an OpsWorks stack with separate layers for each operating system, and get a recipe from the Chef supermarket to run the patch commands for each layer during maintenance windows.
   • Use a shell script to install the latest OS patches on the Linux servers using yum and schedule it to run automatically using cron. Use Windows Update to automatically patch Windows servers.
   • Use AWS Systems Manager Parameter Store to securely store credentials for each Linux and Windows server. Create Systems Manager Resource Groups. Use the Systems Manager Run Command to remotely deploy patch updates using the credentials in Systems Manager Parameter Store

3. A company is setting up a centralized logging solution on AWS and has several requirements. The company wants its Amazon CloudWatch Logs and VPC Flow logs to come from different sub accounts and to be delivered to a single auditing account. However, the number of sub accounts keeps changing. The company also needs to index the logs in the auditing account to gather actionable insight.

   How should a DevOps Engineer implement the solution to meet all of the company’s requirements?

   • Use AWS Lambda to write logs to Amazon ES in the auditing account. Create an Amazon CloudWatch subscription filter and use Amazon Kinesis Data Streams in the sub accounts to stream the logs to the Lambda function deployed in the auditing account.
   • Use Amazon Kinesis Streams to write logs to Amazon ES in the auditing account. Create a CloudWatch subscription filter and use Kinesis Data Streams in the sub accounts to stream the logs to the Kinesis stream in the auditing account.
   • Use Amazon Kinesis Firehose with Kinesis Data Streams to write logs to Amazon ES in the auditing account. Create a CloudWatch subscription filter and stream logs from sub accounts to the Kinesis stream in the auditing account.
   • Use AWS Lambda to write logs to Amazon ES in the auditing account. Create a CloudWatch subscription filter and use Lambda in the sub accounts to stream the logs to the Lambda function deployed in the auditing account.

4. A company wants to use a grid system for a proprietary enterprise in-memory data store on top of AWS. This system can run in multiple server nodes in any Linux-based distribution. The system must be able to reconfigure the entire cluster every time a node is added or removed. When adding or removing nodes, an /etc./cluster/nodes. config file must be updated, listing the IP addresses of the current node members of that cluster

   The company wants to automate the task of adding new nodes to a cluster.

   What can a DevOps Engineer do to meet these requirements?

   • Use AWS OpsWorks Stacks to layer the server nodes of that cluster. Create a Chef recipe that populates the content of the /etc/cluster/nodes. config file and restarts the service by using the current members of the layer. Assign that recipe to the Configure lifecycle event.
   • Put the file nodes. config in version control. Create an AWS CodeDeploy deployment configuration and deployment group based on an Amazon EC2 tag value for the cluster nodes. When adding a new node to the cluster, update the file with all tagged instances, and make a commit in version control. Deploy the new file and restart the services.
   • Create an Amazon S3 bucket and upload a version of the etc/cluster/nodes. config file. Create a crontab script that will poll for that S3 file and download it frequently. Use a process manager, such as Monit or systemd, to restart the cluster services when it detects that the new file was modified. When adding a node to the cluster, edit the file’s most recent members. Upload the new file to the S3 bucket.
   • Create a user data script that lists all members of the current security group of the cluster and automatically updates the /etc/cluster/nodes. config file whenever a new instance is added to the cluster

5. A company has established tagging and configuration standards for its infrastructure resources running on AWS. A DevOps Engineer is developing a design that will provide a near-real-time dashboard of the compliance posture with the ability to highlight violations.

   Which approach meets the stated requirements?

   • Define the resource configurations in AWS Service Catalog, and monitor the AWS Service Catalog compliance and violations in Amazon CloudWatch. Then, set up and share a live CloudWatch dashboard. Set up Amazon SNS notifications for violations and corrections.
   • Use AWS Config to record configuration changes and output the data to an Amazon S3 bucket. Create an Amazon QuickSight analysis of the dataset, and use the information on dashboards and mobile devices.
   • Create a resource group that displays resources with the specified tags and those without tags. Use the AWS Management Console to view compliant and non-compliant resources.
   • Define the compliance and tagging requirements in Amazon Inspector. Output the results to Amazon CloudWatch Logs. Build a metric filter to isolate the monitored elements of interest and present the data in a CloudWatch dashboard.

6. A production account has a requirement that any Amazon EC2 instance that has been logged into manually must be terminated within 24 hours. All applications in the production account are using Auto Scaling groups with Amazon CloudWatch Logs agent configured.

   How can this process be automated?

   • Create a CloudWatch Logs subscription to an AWS Step Functions application. Configure the function to add a tag to the EC2 instance that produced the login event and mark the instance to be decommissioned. Then create a CloudWatch Events rule to trigger a second AWS Lambda function once a day that will terminate all instances with this tag.
   • Create a CloudWatch alarm that will trigger on the login event. Send the notification to an Amazon SNS topic that the Operations team is subscribed to, and have them terminate the EC2 instance within 24 hours.
   • Create a CloudWatch alarm that will trigger on the login event. Configure the alarm to send to an Amazon SQS queue. Use a group of worker instances to process messages from the queue, which then schedules the Amazon CloudWatch Events rule to trigger.
   • Create a CloudWatch Logs subscription in an AWS Lambda function. Configure the function to add a tag to the EC2 instance that produced the login event and mark the instance to be decommissioned. Create a CloudWatch Events rule to trigger a daily Lambda function that terminates all instances with this tag.

7. A DevOps Engineer is implementing a mechanism for canary testing an application on AWS. The application was recently modified and went through security, unit, and functional testing. The application needs to be deployed on an AutoScaling group and must use a Classic Load Balancer.

   Which design meets the requirement for canary testing?

   • Create a different Classic Load Balancer and Auto Scaling group for blue/green environments. Use Amazon Route 53 and create weighted A records on Classic Load Balancer.
   • Create a single Classic Load Balancer and an Auto Scaling group for blue/green environments. Use Amazon Route 53 and create A records for Classic Load Balancer IPs. Adjust traffic using A records.
   • Create a single Classic Load Balancer and an Auto Scaling group for blue/green environments. Create an Amazon CloudFront distribution with the Classic Load Balancer as the origin. Adjust traffic using CloudFront.
   • Create a different Classic Load Balancer and Auto Scaling group for blue/green environments. Create an Amazon API Gateway with a separate stage for the Classic Load Balancer. Adjust traffic by giving weights to this stage.

8. An online retail company based in the United States plans to expand its operations to Europe and Asia in the next six months. Its product currently runs on Amazon EC2 instances behind an Application Load Balancer. The instances run in an Amazon EC2 Auto Scaling group across multiple Availability Zones. All data is stored in an Amazon Aurora database instance.

   When the product is deployed in multiple regions, the company wants a single product catalog across all regions, but for compliance purposes, its customer information and purchases must be kept in each region.

   How should the company meet these requirements with the LEAST amount of application changes?

   • Use Amazon Redshift for the product catalog and Amazon DynamoDB tables for the customer information and purchases.
   • Use Amazon DynamoDB global tables for the product catalog and regional tables for the customer information and purchases.
   • Use Aurora with read replicas for the product catalog and additional local Aurora instances in each region for the customer information and purchases.
   • Use Aurora for the product catalog and Amazon DynamoDB global tables for the customer information and purchases.

9. A company has several AWS accounts. The accounts are shared and used across multiple teams globally, primarily for Amazon EC2 instances. Each EC2 instance has tags for team, environment, and cost center to ensure accurate cost allocations.

   How should a DevOps Engineer help the teams audit their costs and automate infrastructure cost optimization across multiple shared environments and accounts?

   • Set up a scheduled script on the EC2 instances to report utilization and store the instances in an Amazon DynamoDB table. Create a dashboard in Amazon QuickSight with DynamoDB as the source data to find underutilized instances. Set up triggers from Amazon QuickSight in AWS Lambda to reduce underutilized instances.
   • Create a separate Amazon CloudWatch dashboard for EC2 instance tags based on cost center, environment, and team, and publish the instance tags out using unique links for each team. For each team, set up a CloudWatch Events rule with the CloudWatch dashboard as the source, and set up a trigger to initiate an AWS Lambda function to reduce underutilized instances.
   • Create an Amazon CloudWatch Events rule with AWS Trusted Advisor as the source for low utilization EC2 instances. Trigger an AWS Lambda function that filters out reported data based on tags for each team, environment, and cost center, and store the Lambda function in Amazon S3. Set up a second trigger to initiate a Lambda function to reduce underutilized instances.
   • Use AWS Systems Manager to track instance utilization and report underutilized instances to Amazon CloudWatch. Filter data in CloudWatch based on tags for team, environment, and cost center. Set up triggers from CloudWatch into AWS Lambda to reduce underutilized instances

10. A company has a hybrid architecture solution in which some legacy systems remain on-premises, while a specific cluster of servers is moved to AWS. The company cannot reconfigure the legacy systems, so the cluster nodes must have a fixed hostname and local IP address for each server that is part of the cluster. The DevOps Engineer must automate the configuration for a six-node cluster with high availability across three Availability Zones (AZs), placing two elastic network interfaces in a specific subnet for each AZ. Each node’s hostname and local IP address should remain the same between reboots or instance failures.

    Which solution involves the LEAST amount of effort to automate this task?

    • Create an AWS Elastic Beanstalk application and a specific environment for each server of the cluster. For each environment, give the hostname, elastic network interface, and AZ as input parameters. Use the local health agent to name the instance and attach a specific elastic network interface based on the current environment.
    • Create a reusable AWS CloudFormation template to manage an Amazon EC2 Auto Scaling group with a minimum size of 1 and a maximum size of 1. Give the hostname, elastic network interface, and AZ as stack parameters. Use those parameters to set up an EC2 instance with EC2 Auto Scaling and a user data script to attach to the specific elastic network interface. Use CloudFormation nested stacks to nest the template six times for a total of six nodes needed for the cluster, and deploy using the master template.
    • Create an Amazon DynamoDB table with the list of hostnames, subnets, and elastic network interfaces to be used. Create a single AWS CloudFormation template to manage an Auto Scaling group with a minimum size of 6 and a maximum size of 6. Create a programmatic solution that is installed in each instance that will lock/release the assignment of each hostname and local IP address, depending on the subnet in which a new instance will be launched.
    • Create a reusable AWS CLI script to launch each instance individually, which will name the instance, place it in a specific AZ, and attach a specific elastic network interface. Monitor the instances, and in the event of failure, replace the missing instance manually by running the script again.

11. An education company has a Docker-based application running on multiple Amazon EC2 instances in an Amazon ECS cluster. When deploying a new version of the application, the Developer, pushes a new image to a private Docker container registry, and then stops and starts all tasks to ensure that they all have the latest version of the application. The Developer discovers that new tasks are occasionally running with an old image.

    How can this issue be prevented?

    • After pushing the new image, restart ECS Agent, and then start the tasks.
    • Use “latest” for the Docker image tag in the task definition.
    • Update the digest on the task definition when pushing the new image.
    • Use Amazon ECR for a Docker container registry.
    Explanation:

    When a new task starts, the Amazon ECS container agent pulls the latest version of the specified image and tag for the container to use. However, subsequent updates to a repository image are not propagated to already

12. A financial institution provides security-hardened AMIs of Red Hat Enterprise Linux 7.4 and Windows Server 2016 for its application teams to use in deployments. A DevOps Engineer needs to implement an automated daily check of each AMI to monitor for the latest CVE.

    How should the Engineer implement these checks using Amazon Inspector?

    • Install the Amazon Inspector agent in each AMI. Configure AWS Step Functions to launch an Amazon EC2 instance for each operating system from the hardened AMI, and tag the instance with SecurityCheck: True. Once EC2 instances have booted up, Step Functions will trigger an Amazon Inspector assessment for all instances with the tag SecurityCheck: True. Implement a scheduled Amazon CloudWatch Events rule that triggers Step Functions once each day.
    • Tag each AMI with SecurityCheck: True. Configure AWS Step Functions to first compose an Amazon Inspector assessment template for all AMIs that have the tag SecurityCheck: True and second to make a call to the Amazon Inspector API action StartAssessmentRun. Implement a scheduled Amazon CloudWatch Events rule that triggers Step Functions once each day.
    • Tag each AMI with SecurityCheck: True. Implement a scheduled Amazon Inspector assessment to run once each day for all AMIs with the tag SecurityCheck: True. Amazon Inspector should automatically launch an Amazon EC2 instance for each AMI and perform a security assessment.
    • Tag each instance with SecurityCheck: True. Implement a scheduled Amazon Inspector assessment to run once each day for all instances with the tag SecurityCheck: True. Amazon Inspector should automatically perform an in-place security assessment for each AMI.

13. A Development team uses AWS CodeCommit for source code control. Developers apply their changes to various feature branches and create pull requests to move those changes to the master branch when they are ready for production. A direct push to the master branch should not be allowed. The team applied the AWS managed policy AWSCodeCommitPowerUser to the Developers’ IAM Rote, but now members are able to push to the master branch directly on every repository in the AWS account.

    What actions should be taken to restrict this?

    • Create an additional policy to include a deny rule for the codecommit:GitPush action, and include a restriction for the specific repositories in the resource statement with a condition for the master reference.
    • Remove the IAM policy and add an AWSCodeCommitReadOnly policy. Add an allow rule for the codecommit:GitPush action for the specific repositories in the resource statement with a condition for the master reference.
    • Modify the IAM policy and include a deny rule for the codecommit:GitPush action for the specific repositories in the resource statement with a condition for the master reference.
    • Create an additional policy to include an allow rule for the codecommit:GitPush action and include a restriction for the specific repositories in the resource statement with a condition for the feature branches reference.

14. A Developer is designing a continuous deployment workflow for a new Development team to facilitate the process for source code promotion in AWS. Developers would like to store and promote code for deployment from development to production while maintaining the ability to roll back that deployment if it fails.

    Which design will incur the LEAST amount of downtime?

    • Create one repository in AWS CodeCommit. Create a development branch to hold merged changes. Use AWS CodeBuild to build and test the code stored in the development branch triggered on a new commit. Merge to the master and deploy to production by using AWS CodeDeploy for a blue/green deployment.
    • Create one repository for each Developer in AWS CodeCommit and another repository to hold the production code. Use AWS CodeBuild to merge development and production repositories, and deploy to production by using AWS CodeDeploy for a blue/green deployment.
    • Create one repository for development code in AWS CodeCommit and another repository to hold the production code. Use AWS CodeBuild to merge development and production repositories, and deploy to production by using AWS CodeDeploy for a blue/green deployment.
    • Create a shared Amazon S3 bucket for the Development team to store their code. Set up an Amazon CloudWatch Events rule to trigger an AWS Lambda function that deploys the code to production by using AWS CodeDeploy for a blue/green deployment.

15. A DevOps Engineer discovered a sudden spike in a website’s page load times and found that a recent deployment occurred. A brief diff of the related commit shows that the URL for an external API call was altered and the connecting port changed from 80 to 443. The external API has been verified and works outside the application. The application logs show that the connection is now timing out, resulting in multiple retries and eventual failure of the call.

    Which debug steps should the Engineer take to determine the root cause of the issue?

    • Check the VPC Flow Logs looking for denies originating from Amazon EC2 instances that are part of the web Auto Scaling group. Check the ingress security group rules and routing rules for the VPC.
    • Check the existing egress security group rules and network ACLs for the VPC. Also check the application logs being written to Amazon CloudWatch Logs for debug information.
    • Check the egress security group rules and network ACLs for the VPC. Also check the VPC flow logs looking for accepts originating from the web Auto Scaling group.
    • Check the application logs being written to Amazon CloudWatch Logs for debug information. Check the ingress security group rules and routing rules for the VPC.

16. An Engineering team manages a Node.js e-commerce application. The current environment consists of the following components:

    • Amazon S3 buckets for storing content
    • Amazon EC2 for the front-end web servers
    • AWS Lambda for executing image processing
    • Amazon DynamoDB for storing session-related data

    The team expects a significant increase in traffic to the site. The application should handle the additional load without interruption. The team ran initial tests by adding new servers to the EC2 front-end to handle the larger load, but the instances took up to 20 minutes to become fully configured. The team wants to reduce this configuration time.
    What changes will the Engineering team need to implement to make the solution the MOST resilient and highly available while meeting the expected increase in demand?

    • Use AWS OpsWorks to automatically configure each new EC2 instance as it is launched. Configure the EC2 instances by using an Auto Scaling group behind an Application Load Balancer across multiple Availability Zones. Implement Amazon DynamoDB Auto Scaling. Use Amazon Route 53 to point the application DNS record to the Application Load Balancer.
    • Deploy a fleet of EC2 instances, doubling the current capacity, and place them behind an Application Load Balancer. Increase the Amazon DynamoDB read and write capacity units. Add an alias record that contains the Application Load Balancer endpoint to the existing Amazon Route 53 DNS record that points to the application.
    • Configure Amazon CloudFront and have its origin point to Amazon S3 to host the web application. Implement Amazon DynamoDB Auto Scaling. Use Amazon Route 53 to point the application DNS record to the CloudFront DNS name.
    • Use AWS Elastic Beanstalk with a custom AMI including all web components. Deploy the platform by using an Auto Scaling group behind an Application Load Balancer across multiple Availability Zones. Implement Amazon DynamoDB Auto Scaling. Use Amazon Route 53 to point the application DNS record to the Elastic Beanstalk load balancer.

17. A DevOps Engineer is working on a project that is hosted on Amazon Linux and has failed a security review. The DevOps Manager has been asked to review the company buildspec.yaml file for an AWS CodeBuild project and provide recommendations. The buildspec.yaml file is configured as follows:

    

    What changes should be recommended to comply with AWS security best practices? (Choose three.)

    • Add a post-build command to remove the temporary files from the container before termination to ensure they cannot be seen by other CodeBuild users.
    • Update the CodeBuild project role with the necessary permissions and then remove the AWS credentials from the environment variable.
    • Store the DB_PASSWORD as a SecureString value in AWS Systems Manager Parameter Store and then remove the DB_PASSWORD from the environment variables.
    • Move the environment variables to the ‘db-deploy-bucket’ Amazon S3 bucket, add a prebuild stage to download, then export the variables.
    • Use AWS Systems Manager run command versus scp and ssh commands directly to the instance.
    • Scramble the environment variables using XOR followed by Base64, add a section to install, and then run XOR and Base64 to the build phase.

18. A Development team is building more than 40 applications. Each app is a three-tiered web application based on an ELB Application Load Balancer, Amazon EC2, and Amazon RDS. Because the applications will be used internally, the Security team wants to allow access to the 40 applications only from the corporate network and block access from external IP addresses. The corporate network reaches the internet through proxy servers. The proxy servers have 12 proxy IP addresses that are being changed one or two times per month. The Network Infrastructure team manages the proxy servers; they upload the file that contains the latest proxy IP addresses into an Amazon S3 bucket. The DevOps Engineer must build a solution to ensure that the applications are accessible from the corporate network.

    Which solution achieves these requirements with MINIMAL impact to application development, MINIMAL operational effort, and the LOWEST infrastructure cost?

    • Implement an AWS Lambda function to read the list of proxy IP addresses from the S3 object and to update the ELB security groups to allow HTTPS only from the given IP addresses. Configure the S3 bucket to invoke the Lambda function when the object is updated. Save the IP address list to the S3 bucket when they are changed.
    • Ensure that all the applications are hosted in the same Virtual Private Cloud (VPC). Otherwise, consolidate the applications into a single VPC. Establish an AWS Direct Connect connection with an active/standby configuration. Change the ELB security groups to allow only inbound HTTPS connections from the corporate network IP addresses.
    • Implement a Python script with the AWS SDK for Python (Boto), which downloads the S3 object that contains the proxy IP addresses, scans the ELB security groups, and updates them to allow only HTTPS inbound from the given IP addresses. Launch an EC2 instance and store the script in the instance. Use a cron job to execute the script daily.
    • Enable ELB security groups to allow HTTPS inbound access from the Internet. Use Amazon Cognito to integrate the company’s Active Directory as the identity provider. Change the 40 applications to integrate with Amazon Cognito so that only company employees can log into the application. Save the user access logs to Amazon CloudWatch Logs to record user access activities

19. A company is implementing AWS CodePipeline to automate its testing process. The company wants to be notified when the execution state fails and used the following custom event pattern in Amazon CloudWatch:

    

    Which type of events will match this event pattern?

    • Failed deploy and build actions across all the pipelines.
    • All rejected or failed approval actions across all the pipelines.
    • All the events across all pipelines.
    • Approval actions across all the pipelines.

20. A company is using several AWS CloudFormation templates for deploying infrastructure as code. In most of the deployments, the company uses Amazon EC2 Auto Scaling groups. A DevOps Engineer needs to update the AMIs for the Auto Scaling group in the template if newer AMIs are available.

    How can these requirements be met?

    • Manage the AMI mappings in the CloudFormation template. Use Amazon CloudWatch Events for detecting new AMIs and updating the mapping in the template. Reference the map in the launch configuration resource block.
    • Use conditions in the AWS CloudFormation template to check if new AMIs are available and return the AMI ID. Reference the returned AMI ID in the launch configuration resource block.
    • Use an AWS Lambda-backed custom resource in the template to fetch the AMI IDs. Reference the returned AMI ID in the launch configuration resource block.
    • Launch an Amazon EC2 m4.small instance and run a script on it to check for new AMIs. If new AMIs are available, the script should update the launch configuration resource block with the new AMI ID.