DevOps aims to streamline the process from writing code to deploying applications by encouraging collaboration between developers and operations teams. It utilizes tools that automate the integration, testing and deployment of code changes. The key aspects are using version control systems like Git for code management, branching to allow parallel work without disrupting the main code, and continuous integration pipelines that automatically build, test and deploy code changes. This helps catch bugs early and allows rapid yet stable releases.

1. DevOps presentation

2. What is DevOps
● A buzz word
● A culture among developers
● A combination of many different tools
● An environment where building, testing
and releasing happens rapidly and
frequently

3. What is DevOps really though?
● The entire pipeline from source code to
production deployment
Source
Code
Testing Packaging Distribution Production
Deployment

4. Source Code
● Version management is essential
● Tools:
– Git
– Subversion
– Bazaar
– ...

5. Version Management
● Keep track of all software revisions
● Allow multiple developers to work in
parallel
● At Axsh we use git and github

6. Version Management
● Every revision to the code is a commit
● We can now track every revision of the
code
● Every revision can be reverted if needed
Commit Commit Commit Commit

7. Multiple developers
● Multiple people can commit to the code

8. Multiple developers
● What if somebody breaks the code?

9. Multiple developers
● What if somebody breaks the code?

10. Solution: branching
Master branch
Feature branch 1
Feature branch 2

11. Branching benefits
● Developers don’t get in each others way
● Safe to experiment and break the code
since Master branch is not affected

12. Merging
● When a branch is finished, merge back
into Master
Master branch
Feature branch 1
Feature branch 2

13. Merging
● When master advances, merge it into
feature branches
Master branch
Feature branch 2

14. Merging
● Again, when a feature branch is done,
merge it to master
Master branch
Feature branch 2

15. Good branching culture
● Never commit directly to master
● Every time a new feature or bugfix starts,
cut a new branch from master
● When a feature branch is done
– Review code
– Run automatic tests
– Merge
– Delete feature branch

16. How to test a feature branch
● Run unit tests:
– Quick tests that each cover a small part of
the code
● Build packages
● Install on test environment just like you
would on production
● Run integration tests
– Test the entire software system like it would
be used in production

17. Unit test example
public class MyUnit {
public String concatenate(String one, String two) {
return one + two;
}
}
public class MyUnitTest {
public void testConcatenate() {
MyUnit myUnit = new MyUnit();
String result = myUnit.concatenate("one", "two");
assertEquals("onetwo", result);
}
}
The test:
The code:

18. Unit tests
● Are very small
● Are very quick
● Test only one specific part of the code
● Can be done repeatedly while writing
code (Test Driven Development)

19. Integration testing
● Deploy the entire application on an
environment similar to production
● Test the application just like a real client
would use it
● Integration tests take a long time
● They should run at the end of a feature
branch

20. Effective testing
● Should be done automatically using CI
● Should be simple and repeatable
● Should report test results

21. Code review
● Automated tests ensure the code works
● Developers needs to ensure code quality
● Feature branches needs to get approval
from another developer before merge
● Some teams use automatic code review
tools

22. Jenkins
Axsh’s CI system
Source
Code
Github
Unit Tests Package
build
Test env
Deploy
Integration
Tests
Distribution
Yum
Repository
Reporting