Which solution should the DevOps engineer use?
Upload the application as a Docker image that contains all the necessary software to Amazon ECR. Create an Amazon ECS cluster using an AWS Fargate launch type and an Auto Scaling group. Create an AWS CodePipeline pipeline that uses Amazon ECR as a source and Amazon ECS as a deployment provider.
Upload the application code to an AWS CodeCommit repository with a saved configuration file to configure and install the software. Create an AWS Elastic Beanstalk web server tier and a load balanced-type environment that uses the Tomcat solution stack. Create an AWS CodePipeline pipeline that uses CodeCommit as a source and Elastic Beanstalk as a deployment provider.
Upload the application code to an AWS CodeCommit repository with a set of .ebextensions files to configure and install the software. Create an AWS Elastic Beanstalk worker tier environment that uses the Tomcat solution stack. Create an AWS CodePipeline pipeline that uses CodeCommit as a source and Elastic Beanstalk as a deployment provider.
Upload the application code to an AWS CodeCommit repository with an appspec.yml file to configure and install the necessary software. Create an AWS CodeDeploy deployment group associated with an Amazon EC2 Auto Scaling group. Create an AWS CodePipeline pipeline that uses CodeCommit as a source and CodeDeploy as a deployment provider.
Explanations:
While using Docker images allows for a consistent environment and the use of Amazon ECS with Fargate provides scalability, this option does not explicitly mention the ability to tune OS-level parameters, which is required for the application’s proper functioning. Additionally, using Fargate may not support the specific versions of software (Tomcat, HAProxy, and Varnish Cache) unless packaged correctly in the Docker image.
AWS Elastic Beanstalk can handle deployments and offers scaling; however, it is not ideal for applications requiring specific versions of software like Tomcat, HAProxy, and Varnish Cache as it may not allow for necessary OS-level tuning. Furthermore, Elastic Beanstalk is more opinionated about its environments and may not provide full control over the configuration.
Similar to Option B, while Elastic Beanstalk can deploy applications and is capable of scaling, using a worker tier environment is inappropriate for web applications that depend on Tomcat. Additionally, it may not allow for the necessary OS-level tuning or specific software version management required by the application.
This option allows for precise control over the configuration and installation of software through an appspec.yml file, making it suitable for specific version requirements of Apache Tomcat, HAProxy, and Varnish Cache. Using AWS CodeDeploy with an Auto Scaling group ensures that faulty servers are replaced automatically and allows for tuning OS-level parameters, fulfilling all requirements of the migration.