Continuous Integration
- 2. What is Integration? Definition: “the act of combining into an integral whole” In software development, integration includes… Combining source files Combining software and environment Combining software and data Combining software and requirements (tests) Combining developers Pooja Mantri Continuous Integration
- 3. Integration Testing in SDLC Combine the application’s components into working software. Historically done near the end of the project. Very risky! Software modules don’t always work together as expected Best case: Time to fix, time to retest that module Worst case: Time to determine why, time to redesign, time to fix, time to test all of the modules affected by the redesign. Pooja Mantri Continuous Integration
- 4. Nightly Builds Practice became popular in the late 90s after Microsoft published its development practices Integrate all of the software on a nightly basis. Smoke Test – run the application and conduct a minimal set of tests to see if it “catches fire”. Pooja Mantri Continuous Integration
- 5. Take it to the Extreme Extreme Programming says… if testing is good, test all the time if integration testing is important, integrate and test all the time if short iterations are good, make the iterations really, really short (minutes and hours, not weeks and months) Continuous Integration is born. Pooja Mantri Continuous Integration
- 6. What is Continuous Integration? It describes a set of software engineering practices that speed up the delivery of software by decreasing integration times. Integrates source code and runs tests after each commit of code to the source repository. Near-immediate feedback to the developer from the authoritative source, the system itself. Pooja Mantri Continuous Integration
- 7. Example: Development of a Small Feature Assumption: We have to do something which can be competed in few hours. The actual task doesn’t matter. Development checks out current coy of the integrated source code. He performs his task, tests it and commits the changes to the repository. Pooja Mantri Continuous Integration
- 8. The builder than merges the copy to the mainline. If any conflicts found they are fixed by the developer. If no merge conflicts, builder builds the project on integration machine based on mainline code. If compilation error, developer fixes it and repeats the process until builder can build a working copy which is properly synchronized with the mainline. Pooja Mantri Continuous Integration
- 9. Task is completed on if after a successful build. If a clash between two developers exist, it is caught either when Second developer commits his local copy or Integration build fails Thus error is detected rapidly In continuous integration a failed integration build should never remain failed for long. Pooja Mantri Continuous Integration
- 10. Practices of continuous Integration Maintain a single source repository Automate the build Make your build self-testing Everyone commits frequently Every commit should build the mainline on an integration machine Keep the build fast Make it easy for anyone to get the latest executable Everyone can see what’s happening Automate deployment Pooja Mantri Continuous Integration
- 11. Nightly vs. Continuous Builds Nightly builds generate deliverables. They result in something tangible: something for QA to test something for product managers to review something to reassure team members that they are in fact building a product. Because of the external audience, the nightly build is a formal event, a mini-milestone that your team should hit without fail. Breaking the nightly build is something that generates blame and often consequences, such as becoming the build mother or being awarded a dunce cap. Continuous Integration builds don’t need durable build products to be beneficial. They are a way for a developer to have a conversation with the system to gain reassurance that they have done their part. Both must be used Pooja Mantri Continuous Integration
- 12. Benefits of Continuous Integration It minimizes integration risk. It supports easier defect diagnosis. Frequent Deployment It saves time creating releases. Encourages good testing habits It enables other good development practices… Pooja Mantri Continuous Integration
- 13. C.I. Enables other Practices Test Driven Development Fewer bugs, less time debugging Confidence to refactor Executable Documentation Validation that you are complete Release Management Builds are centralized Builds are repeatable/re-creatable Modifications are clearly mapped to releases Issues are clearly mapped to releases and thus to modifications Releases are only created with committed code Digitally signed code Enforcement of Company Development Policy Automate policy tests with Checkstyle Manual code reviews can focus on design not syntax Pooja Mantri Continuous Integration