Continuous integration (CI) and continuous delivery (CD) are software engineering practices that involve regularly merging code changes into a shared repository and performing automated builds and tests. CI involves integrating code changes daily to find issues early, while CD ensures code can be reliably released at any time through short development cycles with automated testing, deployment, and documentation. Implementing CI/CD helps build better quality software faster and cheaper by identifying defects early, encouraging collaboration, and facilitating frequent releases.

1. Continuous Integration &
Continuous Delivery
Denis Ristic

2. Or,
how to build software
better, faster, cheaper

3. Who am I?
@denisristic
denis.ristic@perpetuum.hr
● Software architect
● Developer
● Team Leader
● Scrum Master
● DevOps engineer

4. CI Definition
CI is the practice in software
engineering of merging all working
copies with a shared mainline several
times a day
[Wikipedia]

5. What is CI?
● a development methodology
● of daily developer integrations
● verified by automated builds

6. What is not CI?
● nightly builds
● dev branches
● building via IDEs

7. Building software
can be a risky
business
● Fixing bugs late is costly
● Lack of team cohesion
● Poor quality code base
● Lack of project visibility
● Lack of deployable software

8. How CI works?
Better
● Build better quality software
● That is tested early and often
● Using best practices and
coding standards
Faster
● Test in parallel, not at the end
● No integration points
● Builds become a non event
Cheaper
● Identify defects earlier
● Fix when least costly
● Easy repetable testing

9. CD Definition
CD is a software engineering
approach in which teams produce
software in short cycles, ensuring that
the software can be reliably released
at any time
[Wikipedia]

10. CD Ingredients
● Compilation
● Tests execution
● Database integration
● Code inspection
● Automated deployment (!!!)
● Documentation generation

11. Compilation
● Ensure code actually compiles
● On every target platform

12. Test Execution
● Ensures product functions as expected
● Through repeatable testing

13. Database Integration
● Ensures that DB and code are in sync
● Automates (re)creation of DB and test data

14. Code Inspections
● Ensures a healthy code base
● Identifies problems early
● Enforces best practices

15. Automated Deployment
● Products can be released anytime
● Continually demo-able state
● Eliminates “works on my machine”

16. Document Generation
● Ensures documentation is current
● Removes burden from developers
● Products build reports and metrics

17. How do I get started?

18. When do I build?
● At every check-in
● Every time a dependency changes

19. How do I build?
● Use a single build script
● That can run from console
● Do not depend on an IDE

20. How to do it continuously?
● Use a dedicated CI server, not cron
● Trigger on all daily check-ins
● Not (only) at midnight

21. Pay attention to your builds
● Provide immediate feedback
● Make it easily accessible
● Require no developer effort

22. Metrics Matter
● Identify key metrics and track them visually
● Act on them immediately

23. Cookbook

24. 7 steps
1. Commit early, commit often
2. Never commit broken code
3. Fix build failures immediately
4. Fail fast
5. Act on metrics
6. Build in every target environment
7. Create artifacts from every build

25. Summary

26. Continuous Integration
Can help you build better quality
software faster, with
more confidence

27. The End