Azure DevOps provides a powerful and versatile platform for implementing Continuous Integration (CI) practices. CI is a key DevOps practice that involves automating the building, testing, and validation of code changes as they are integrated into a shared repository. Azure DevOps supports CI through its build and release pipelines. Here’s how Azure DevOps CI works:

1. Source Code Management:

   • Azure DevOps allows you to connect to version control systems such as Git, Azure Repos (formerly known as VSTS), GitHub, or Subversion. Your source code is stored in repositories, and changes are tracked through commits.

2. Build Pipelines:

   • Build pipelines in Azure DevOps are used to automate the process of building, compiling, and packaging your application code. You can define build steps, specify build agents, and configure triggers for when builds should run.

3. Triggering Builds:

   • Builds can be triggered manually, on code commits (continuous integration trigger), or on pull requests. This ensures that code changes are automatically validated upon submission.

4. Build Agents:

   • Azure DevOps provides hosted build agents that are pre-configured with various development tools and runtimes. You can also set up your own self-hosted build agents to match your specific requirements.

5. Build Artifacts:

   • After a successful build, Azure DevOps generates artifacts such as compiled binaries, libraries, or application packages. These artifacts can be used in subsequent stages of the CI/CD pipeline.

6. Unit Testing:

   • Azure DevOps build pipelines can include unit tests as part of the build process. Test results are recorded and can be used to assess the quality of code changes.

7. Integration Testing:

   • If needed, integration tests can be included in the build pipeline to ensure that different components of the application work together correctly.

8. Code Analysis and Quality Checks:

   • You can integrate code analysis and static code quality checks into the build pipeline. Common tools like SonarQube or third-party extensions can be used for this purpose.

9. Containerization:

   • Azure DevOps supports the creation of container images as part of the build process. Docker images can be built and pushed to container registries.

10. Custom Scripts and Build Tasks:

    • Custom scripts and build tasks can be added to the build pipeline to perform specific actions, such as environment setup, deployment preparation, or custom validation steps.

11. Build Triggers:

    • Build pipelines can be triggered based on events like code commits, pull requests, or scheduled runs. This ensures that code changes are validated automatically and consistently.

12. Parallel Builds:

    • Azure DevOps allows you to run multiple builds in parallel, enabling faster feedback and reduced build times.

13. Integration with CI/CD Pipelines:

    • CI builds can seamlessly feed into CI/CD pipelines, ensuring that only validated and successful builds are deployed to production or other environments.

14. Integration with Deployment Targets:

    • Azure DevOps can deploy the built artifacts to various deployment targets, including on-premises servers, Azure resources, Kubernetes clusters, and more.

15. Logging and Reporting:

    • Azure DevOps provides logs and reporting features that help track the progress and results of CI builds. You can monitor build status, test results, and code quality metrics.

In summary, Azure DevOps CI facilitates the automation of build and validation processes, ensuring that code changes are regularly integrated, tested, and validated. This helps teams detect and address issues early in the development cycle, leading to higher software quality and faster delivery.