Methods and strategies to interact with the AWS software-defined infrastructure

How would you define Infrastructure as Code (IaC), and what AWS services facilitate IaC for DevOps practices?

Infrastructure as Code (IaC) is a method of managing and provisioning computer data centers through machine-readable definition files, rather than physical hardware configuration or interactive configuration tools. AWS services that facilitate IaC include AWS CloudFormation and AWS CDK (Cloud Development Kit), which allow developers to define their infrastructure in code and version it alongside their application source code.

What is AWS CloudFormation, and how does it contribute to software-defined infrastructure?

AWS CloudFormation is a service that provides a common language for you to model and provision AWS and third-party application resources in your cloud environment. It contributes to software-defined infrastructure by allowing developers to use YAML or JSON templates to describe the desired AWS resources, their properties, and the relationship between them, and it automatically handles the provisioning and updating of resources in a predictable, repeatable manner.

Can you explain the purpose and usage of AWS Elastic Beanstalk within the context of software-defined infrastructure?

AWS Elastic Beanstalk is an easy-to-use service for deploying and scaling web applications and services. It abstracts the underlying infrastructure, provisioning the resources necessary to run the application based on a given configuration. It supports software-defined infrastructure by allowing developers to define environment configurations and application versions, which Beanstalk uses to automatically handle the deployment, from capacity provisioning and load balancing to application health monitoring.

What is the AWS Systems Manager, and how does it assist DevOps engineers in managing AWS infrastructure?

AWS Systems Manager is a management service that provides visibility and control over AWS infrastructure. It helps DevOps engineers automate operational tasks, maintain system security and compliance, understand and control their infrastructure state, and maintain consistency in software and infrastructure configuration. Systems Manager facilitates actions like patching, automation, inventory management, and parameter storage.

Describe a scenario where AWS OpsWorks would be more appropriate than AWS CloudFormation for infrastructure management.

AWS OpsWorks would be more appropriate in scenarios where a user requires a managed solution that supports Chef or Puppet, which are automation platforms that allow you to use code to automate the configurations of your servers. OpsWorks provides managed instances of Chef and Puppet and is suitable for those who want to leverage these tools for tasks like continuous deployment and automated configurations while maintaining a more fine-grained control over each layer of the stack.

How would you automate the scaling of an AWS infrastructure based on demand, and what services would you use?

To automate scaling of an AWS infrastructure, I would use AWS Auto Scaling in conjunction with Amazon CloudWatch. Auto Scaling allows you to define scaling policies for your EC2 instances or other AWS resources based on criteria you specify, such as CPU utilization or network I/O, which are monitored by CloudWatch. When the defined thresholds are breached, Auto Scaling can automatically adjust the capacity to maintain steady, predictable performance.

What role does the AWS Command Line Interface (CLI) play in interacting with AWS infrastructure, and can you provide an example of deploying a resource with the CLI?

The AWS Command Line Interface (CLI) is a unified tool to manage AWS services. It allows DevOps engineers to control multiple AWS services directly from the terminal session, script operational procedures, or integrate them with other management tools. To deploy an EC2 instance using the CLI, you would run:
aws ec2 run-instances --image-id ami-abc12345 --count 1 --instance-type tmicro.

Explain how AWS API Gateway supports software-defined infrastructure for serverless applications.

AWS API Gateway acts as the front door for serverless applications on AWS. It allows developers to define HTTP/S endpoints that trigger AWS Lambda functions, providing the infrastructure required to create, publish, maintain, monitor, and secure APIs at any scale. DevOps engineers can define the API interface and link it to the Lambda function using Swagger or OpenAPI specifications, enabling a software-defined interaction model that automatically scales with the usage.

How does AWS SDK (Software Development Kit) enable developers to interact with AWS services programmatically?

AWS SDKs provide language-specific APIs (e.g., Python, Java, .NET) enabling developers to interact with AWS services programmatically within their application code. SDKs handle low-level details like generating signatures, handling request retries, and error handling, allowing developers to manage resources, invoke AWS services, and develop robust cloud applications leveraging the full power of the AWS platform.

What AWS service would you utilize for securely storing and rotating credentials used in your infrastructure automation scripts?

For securely storing and rotating credentials, AWS Secrets Manager should be used. Secrets Manager protects access to applications, services, and IT resources without the upfront investment and on-going maintenance costs of operating your own infrastructure. It enables you to easily rotate, manage, and retrieve database credentials, API keys, and other secrets throughout their lifecycle, automating the process which improves overall security and reduces the risk associated with human error.

Discuss how AWS CodeDeploy enables automated software deployments to a variety of compute services including EC2, Lambda, and on-premises servers.

AWS CodeDeploy is a deployment service that automates software deployments to various compute services such as EC2 instances, AWS Lambda, and on-premises servers. It allows developers to deploy applications consistently with automatic rollbacks and minimal downtime. CodeDeploy takes care of complexities such as updating the application while minimizing impact to the end users, tracking application health according to configurable rules, and executing the correct deployment patterns (all-at-once, rolling, blue/green).

Can you describe the benefits of using AWS Step Functions for orchestrating AWS services in your software-defined infrastructure?

AWS Step Functions allows you to coordinate multiple AWS services into serverless workflows so you can build and update apps quickly. Benefits include visual workflow management which simplifies the development and debugging process, automatic handling of retries and error handling, and the ability to maintain the application’s state in a reliable way. It is particularly good for complex workflows that need long-running, multi-step, and multi-service coordination.