Passed Exam Today DOP-C02

 The UserData property of the AWS: AutoScaling: LaunchConfiguration resource can be used to specify a script that runs when the EC2 instances are launched. This script can include the ECS cluster name as an environment variable for the ECS agent running on the EC2 instances. This way, the EC2 instances will register with the correct ECS cluster. Option A is incorrect because the AWS: ECS: Cluster resource does not have a property to reference the EC2 instances. Option C is incorrect because the EC2 instances are launched by the Auto Scaling group, not by the AWS: EC2: Instance resource. Option D is incorrect because using a custom resource and a Lambda function is unnecessary and overly complex for this scenario. References: AWS::AutoScaling::LaunchConfiguration, Amazon ECS Container Agent Configuration

The requirement is not just to perform a one-time upgrade , but to ensure that Kubernetes and related components stay continuously within the AWS standard support window , with minimal ongoing effort. EKS Auto Mode is designed to reduce operational burden by managing cluster infrastructure, including control plane and data plane lifecycle, in a more automated fashion. When EKS Auto Mode is enabled and existing managed node groups are removed, EKS can manage compute capacity and associated upgrades in a more integrated, hands-off way, tracking supported versions automatically.

Option A ( aws eks update-cluster-version ) and Option C ( eksctl upgrade ) are both manual upgrade mechanisms. They can update clusters to a specific version but do not continuously ensure future upgrades as new supported versions are released; they require the DevOps team to schedule and execute each upgrade. Option D (IaC refactor) is generally a good practice but does not inherently provide automatic version lifecycle management; it also introduces significant upfront effort compared to enabling Auto Mode.

Thus, enabling EKS Auto Mode and deprecating manual managed node groups provides the least operational overhead for staying within the EKS-supported version schedule.

This solution will meet the requirements in the most operationally efficient manner because it will use CloudWatch Logs destination to aggregate the log groups from all the accounts to a single S3 bucket in the logging account. However, unlike option A, this solution will create a CloudWatch Logs destination for each region, instead of a single destination for all regions. This will improve the performance and reliability of the log delivery, as it will avoid cross-region data transfer and latency issues. Moreover, this solution will use an Amazon Kinesis data stream and an Amazon Kinesis Data Firehose delivery stream for each region, instead of a single stream for all regions. This will also improve the scalability and throughput of the log delivery, as it will avoid bottlenecks and throttling issues that may occur with a single stream.