One of my goals for the new year is to pass the AWS DevOps Engineer Professional Exam. In this post, I'll be sharing a summary of my notes and updating it as I continue my journey to certification. [Last updated: 18/06/24]

Exam Guide

Started off by going through the exam guide and seeing which domains will be tested. SDLC Automation has the highest weighting of 22% so this is something to really focus on.

I'm using the following courses to prepare. There is probably an overlap in content so I will take bits from each course to make sure I am covering all topics in depth.

Udemy - https://www.udemy.com/course/aws-certified-devops-engineer-professional-hands-on/

A Cloud Guru - https://www.pluralsight.com/cloud-guru/courses/aws-certified-devops-engineer-professional-dop-c02

Domain 1: SDLC Automation

CI/CD

CodeCommit

• A managed service used to host private git repos

• HA, fault tolerant and scalable

• Need to create HTTPS Git credentials for IAM users

• Can use regular Git commands to create branches etc.

• Data encrypted in transit and at rest

• AWS CodeCommit Power User permissions don't allow for creation or deletion of repos

Key commands:

• aws codecommit create-repository --repository-name

• aws codecommit get-repository --repository-name

• aws codecommit list-repositories

• aws codecommit delete-repository --repository-name

CodeBuild

• Fully managed CI service that compiles source code, runs test and produces packages to deploy

• Output artifacts stored in S3 with versioning enabled

• Can set up CloudWatch events to monitor code and run CodeBuild after a successful merge

• From AWS docs: A buildspec is a collection of build commands and related settings, in YAML format, that CodeBuild uses to run a build. You can include a buildspec as part of the source code or you can define a buildspec when you create a build project

CodeDeploy

• Automates application deployments to AWS services or on prem

• Use EventBridge to detect the result of a deployment job and use SNS or Lambda to notify

• In CodeDeploy an application is a name identifier to reference deployment settings. An appspec file manages deployments

• A deployment group is the instance or instances where you want to deploy code

• Deployment configuration is the number of instances for which you want to deploy your code.

• Predefined deployment configurations: one at a time, half at a time and all at once.

CodePipeline

• A CI service to automate pipelines to build, test and deploy

Domain 2: Configuration Management and IaC

Elastic Beanstalk

• Fully managed service to deploy apps

• Two environment types: single instance and HA

• Configuration options are applied from multiple sources:

  • Directly to the environment

  • Saved Configurations

  • Configuration Files (.ebextensions) – .ebextensions is a folder at the root of the application source bundle

• Docker and RDS:

Lambda

• Default timeout period is 15 minutes

• When a function is created, it doesn’t have any published versions. Unpublished versions are $LATEST which point to all unpublished changes. Once a version is published it becomes immutable.

• Aliases can be used to point to a specific version e.g. dev to $LATEST. Can also be used for canary deployments.

• SAM provides a bridge between Lambda and CloudFormation

API Gateway

Rest API: one way communication, request/response

WebSocket API: two-way communication, request/response and can also send independent communication to client

CloudFormation

IaC that encourages collaboration and uses version control and automation

• A template is a declaration of AWS resourced that make up a stack

• Objects are declared as name-value pair. Resources is the only required section in a template

• Storing templates in a second region is a good DR practice

• Intrinsic functions allow you to dynamically assign values at run time

Domain 3: Resilient Cloud Solutions