16. DevOps

DevOps

What is DevOps?

DevOps

• Creating automation for the entire build / test / release cycle
• Allow development, test and production environments to be built, tested and deployed easily and systematically
• Allow new components to be added automatically
• DevOps = Culture + Practices + Tools

 

Amazon's Case

Amazon.com Monolith -> Microservices

• develping faster than ever
• However, many teams were still being slowed down by manual processes and workflows
• Introduce automated actions and transitions
  • faster, safer, consistent & standardized, visualization of the process

 

Five Major Phases of Software Release

Source > Build > Test > Deploy > Monitor

 

Source

• Checkin souce code, Peer Review

Build

• Compile code, Unit test, Style checkers, Code metrics
• Create container images

Test

• Integration test, Load test, UI test, Penestration test

Deploy

• Deployment to production environments

Monitor

• Monitor code in production

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CI / CD

Continuous Integration (CI)

Continuous Integration (CI)

• integrating code from multiple developers into a central repository, multiple times per day
• continually validating the state of a codebase through automated testing
  • ex, developers push code changes to Git repository, for every push you can create scripts to build and test automatically
• best achieved through integration with version control
  • each change is built and tested automatically and continously

CI build consists of automated process:

• Run automatic code quality scan, and generate a report
• Build code and run any automated tests (mostly unit tests)
• Generate and publish a test coverage report

 

Continous Delivery (CD)

Continuous Delivery

• extension of continuous integration where code changes are automatically prepared for a release to production
• expands CI upon deploying code changes to testing environment and running test and so on after build stage

 

Continuous Deployment (CD)

Continuous Deployment

• every change is deployed to production automatically, without explicit approval from a developer
• building, testing, and releasing software faster and more frequently
  • increase quality, reduce cycle time
• Build + test + deploy continuously

Continuous Delivery: 소프트웨어를 지속적으로 릴리스 가능한 상태로 유지

Continous Deployment: 소프트웨어 변경사항이 자동으로 프로덕션 환경에 배포

 

Benefits of CI/CD

Higher quality

• less bugs and are captured early by automated tests
• developers are alerted as soon as they break a build

Low risk releases

• integration issues have been solved early -> releasing is easire
• deploy small batches of changes -> easy to fix

Lower costs

• cost for fixing an issue in development phase is much lesser than in production
• testing codes are reduced significantly

Better products

• team can focus on what customers care about most - business logic, UX ..

Time to market faster

• eveyrthing is automated
• remove a large amount of re-work effort
• customers see continuous stream of improvements and quality increases every day

Happier team 🤔

• make releases are less painful

CI/CD Tools

- Jenkins is the most popular CI tools: open source, on-premise

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Github Actions

GitHub Actions

• CI/CD platform that allows you to automate your build, test, and deployment pipeline

Componenets of Github Actions

Workflow

• configurable automated process that will run one or more jobs
• defined by a YAML file and will run when triggered by an event in your repository, or they can be triggered manually, or at a defined schedule
• .yml file in the.github/workflows directory

Event

• specific activity in a repository that triggers a workflow run
• activity can originate from GitHub when someone creates a pull request, open an issue, or pushes a commit to a repository
  • you can also trigger a workflow to run on a schedule, by posting to a REST API, or manually

Job

• set of steps in workflow that is executed on the same runner
• each step is either a shell script that will be executed, or an action that will be run
• you can configure a job's dependencies with other jobs
  • by default, jobs have no dependencies and run in parallel with each other

Action

• custom application that performs a complex but frequently repeated task
  • use an action to help reduce the amount of repetitive code
• can pull your git repository from GitHub, set up correct toolchain for your build environment, or set up the authentication to your cloud provider
• you can write your own actions, or you can find actions to use in your workflows in the GitHub Marketplace

Runner

• runner is a server that runs your workflows when they're triggered
• each runner can run a single job at a time
• GitHub provides Ubuntu Linux, Microsoft Windows, and macOS runners
• each workflow run executes in a fresh, newly-provisioned virtual machine