• Continuous Integration & Continuous Delivery/Deployment are Best Practices for software development and deployment
  • They enable frequent software changes to be applied whilst maintaining system and service stability.
  • Companies like AWS, Netflix, Google, and Facebook have pioneered this approach to releasing code, successfully applying thousands of changes per day.

Continuous Integration Workflow

  • Multiple devs working on different features or bug fixes
  • All contributing to the same application
  • Sharing the same code repository e.g. git
  • Frequently pushing their updates into the shared repo - at least daily
  • Code repository integrated with a build management system
  • Code changes trigger an automated build
  • We need a way to ensure that any code change does not break the build or introduce new bugs in the Application
  • The test system runs automated tests on the newly built application
  • Identifies any bugs, preventing issues from being introduced in the master code
  • CI focuses on small code changes which frequently committed into the main repository once they have been successfully tested

Continuous Delivery

  • Continuous Delivery is a Dev practice where merged changes are automatically built, tested, and prepared for released into staging and eventually production environments,
  • There is usually a manual decision process to initiate deployment of the new code.

Continuous Deployment

  • Continuous Deployment takes the idea of automation one step further and automatically deploys the new code following successful testing, eliminating any manual steps.
  • The new code is automatically released as soon as it passes through the stages of your release process (build, test, package)
  • Small changes are released early and frequently
  • Both practices require the build, test, and deployment processes to be fully automated but Continuous Deployment also automates the release process as well

AWS Tools

  • CodeCommit - create private git repository within AWS
  • CodeBuild - fully managed build service & can run basic tests
  • CodeDeploy - automated application deployment service -> EC2 instances/On-premise systems/Lambda functions
  • CodePipeline - continuous deployment service - allows you to model/visualize/automate entire release process

Exam Tips

  • Worth reading white paper:
  • Continuous Integration is about integrating to merging the code changes frequently - at least once per day, enables multiple devs to work on the same Application
  • Continuous Delivery is all about automating the build, test and deployment functions
  • Continuous Deployment fully automates the entire release process, code is deployed into Production as soon as it has successfully passes through the release pipeline
  • AWS CodeCommit - Source Control (git)
  • AWS CodeBuild - compile source code, run tests and package code
  • AWS CodeDeploy - Automated Deployment to EC2, on premises systems and Lambda
  • AWS CodePipeline - CI/CD workflow tool, fully automates the entire release process (build, test, deployment)