Sharing some overview about Jenkins best of my knowledge and used few resources on internet.
Jenkins is an open-source automation server that enables developers to automate various aspects of the software development process. It provides a way to automate building, testing, and deploying software, making it easier for development teams to quickly deliver high-quality software. Jenkins is written in Java and runs on a web application server such as Apache Tomcat.
Below are few uses of Jenkins along with the example.
Suppose we have a web application that is being developed by a team of developers. The application is hosted on a version control system such as Git, and the development team is using an Agile development methodology.
Continuous Integration: Whenever a developer makes a code change and pushes it to Git, Jenkins can automatically detect the change and trigger a build. Jenkins can check out the code from Git, compile the code, and run unit tests to ensure that the changes don't break the existing functionality. If the build and tests are successful, Jenkins can generate a report and notify the team that the changes have been integrated successfully.
Continuous Delivery: Once the code has been built and tested, Jenkins can automatically deploy the application to a staging environment for further testing. This environment could be a virtual machine, a container, or a cloud environment. Jenkins can deploy the application and run integration tests to ensure that it works correctly in the staging environment. If the tests are successful, Jenkins can deploy the application to a production environment.
Automated testing: Jenkins can be integrated with testing frameworks such as Selenium, JUnit, and TestNG to run automated tests on the application. For example, Jenkins can run a suite of Selenium tests to ensure that the application's user interface works correctly. If any tests fail, Jenkins can notify the team so that they can investigate and fix the issue.
Code analysis: Jenkins can be used to perform code analysis using tools such as SonarQube, Checkstyle, and PMD. For example, Jenkins can run a SonarQube analysis to detect code smells, security vulnerabilities, and other issues in the code. If any issues are found, Jenkins can generate a report and notify the team so that they can address the issues.
Build and release management: Jenkins can manage the build and release process for the application. For example, Jenkins can create build artifacts, tag releases in Git, and publish the artifacts to a repository such as Nexus or Artifactory. Jenkins can also manage the release pipeline, deploying the application to various environments such as development, testing, and production.
Infrastructure automation: Jenkins can automate the provisioning and configuration of infrastructure. For example, Jenkins can create and configure virtual machines, containers, and cloud resources such as AWS EC2 instances or Azure VMs. Jenkins can use infrastructure-as-code tools such as Terraform or Ansible to define the infrastructure and automate its creation and configuration.
To summarize, we can say, Jenkins can be used to automate various aspects of the software development process, from building and testing code changes to deploying applications to various environments. It can integrate with a wide range of tools and technologies, making it a powerful tool for managing the software development lifecycle.