Deploying and Operating in AWS

What it is

There are several ways to create and manage AWS resources. You can click through a web page, type commands, write code, or describe the whole environment in a template.

The exam asks you to pick the method that fits a task, and to recognise the three deployment models: cloud, hybrid and on premises.

It also expects you to know the difference between a one time action and a repeatable process.

How it works

Ways to access AWS

Every method ends up calling the same AWS APIs. Using the CLI or an SDK is called programmatic access, and it needs credentials such as access keys or a role.

An example of the AWS CLI listing your Amazon Simple Storage Service (S3) buckets:

aws s3 ls

Another example, listing virtual servers in a chosen Region:

aws ec2 describe-instances --region us-east-1

Infrastructure as code

Infrastructure as code (IaC) means defining your resources in text files and letting a tool build them. The same file creates the same environment every time.

AWS CloudFormation reads a template written in JSON (JavaScript Object Notation) or YAML (YAML Ain't Markup Language) and creates a stack, which is the group of resources the template describes. This small YAML template creates one S3 bucket.

Resources:
  MyBucket:
    Type: AWS::S3::Bucket

The AWS Cloud Development Kit (CDK) lets you describe the same infrastructure in a programming language, and it produces CloudFormation templates.

IaC makes environments repeatable, reviewable and easy to delete. It also lowers human error compared with clicking through the console.

Easier ways to deploy applications

AWS Elastic Beanstalk lets you upload application code while it handles capacity, load balancing and scaling. You still own the resources it creates.

Deployment models

Hybrid is common when a company moves in stages or must keep some data on site. AWS Direct Connect, AWS Site-to-Site virtual private network (VPN) and AWS Storage Gateway connect or extend on premises systems. AWS Outposts places AWS infrastructure inside your own data center.

Operating the environment

Deploying is the start. Day to day operation includes monitoring, patching and keeping a record of changes.

• Amazon CloudWatch collects metrics and logs and raises alarms.
• AWS Systems Manager helps you operate many servers at once, such as running commands and applying patches.
• AWS Service Catalog lets an organisation offer a list of approved products that teams can launch.

One time operations and repeatable processes

A one time task, such as testing an idea, suits the console. A process you will do again, such as building a test environment each week, should be scripted or defined in a template.