Continuous Integration & Deployment

Continuous Integration

• The practice of merging all developer working copies to a shared mainline several times a day.
• Grady Booch first proposed CI in his 1991 method
• Extreme programming (XP) adopted the concept of CI
• It automates build and testing of code every time code is committed for changes.
• Needs a shared version control repository.
• CI prevents integration problems
• Every code change is integrated as it’s developed.

Continuous Delivery

• It is the ability to get changes of all types into production
• Changes include
  • new features
  • configuration changes
  • bug fixes
  • experiments
• The code should always be in a deployable state
• It automates the flow to production.
• It is the process to
  • Build
  • test
  • configure
  • deploy

from a build to a production environment.

• Multiple testing create a Release Pipeline to automate deployment
• Used to sequence multiple deployment “rings” for progressive exposure
• Aims to keep production fresh by achieving shortest path from availability of new code to deployment.
• Uses extensive automation, to minimize time to deploy and mitigate or remediate production incidents (TTM and TTR).

• Involves
  • comprehensive configuration management
  • continuous integration
  • continuous testing