Jenkins in the CI/CD pipeline

What is Jenkins?

Jenkins is a Java-based, open-source DevOps automation tool. This continuous integration tool is primarily designed to automate repetitive tasks such as building, testing, and deployment of software applications. Jenkins is crucial for continuous integration and continuous deployment (CI/CD). With CI/CD in place, developers can focus on writing code while Jenkins takes care of the rest. This saves time and enables faster error mitigation and faster delivery of software.

Why use Jenkins?

Traditional software development involves manual processes in the build-test-deploy cycle that often lead to a higher number of bugs, challenges in integration, and delays in software delivery. Thanks to Jenkins's continuous integration, code is automatically built and tested as and when it gets lodged into source repositories such as Github. It's then packaged and deployed with minimal manual intervention after it passes all the tests.

Jenkins helps organizations accelerate their software development process through CI/CD automation, which is used to build and test software projects continuously, making it easier for developers to integrate changes to the project as and when required. This automation also helps users obtain a fresh build when it's ready. Here are some key reasons why Jenkins's server is popular among testers:

• It's an open-source CI/ CD automation tool.
• There's vast community support and an easy installation process.
• Jenkins supports a wide range of plugins that can be used to automate any task in the software development process.
• It helps developers make continuous changes to the codebase.
• It provides a standardized build and test environment to ensure the deployed feature works on machines with different configurations.

Jenkins software and its architecture

In big projects, the build process distributes the load among various machines to improve efficiency. Jenkins follows master-slave architecture to manage such distributed builds. A Jenkins build provides a way to automate a specific task or execute jobs in a sequential manner. It's a process where the source code is transformed into a tangible product that can be executed in any environment. This helps in building large projects with multiple codebases, or when there are different environments for testing or staging. Various projects can run simultaneously regardless of the project size.

Jenkins master node

Jenkins's master node acts as a central point of control and distributes the workload to its slaves. The Jenkins master executes the workflows as per the pipelines.

Jenkins slaves or agents

Jenkins's slave is a java program that runs on a remote machine and listens for request from the Jenkins master. Slaves can work on a variety of operating systems such as Windows, Linux, and so on. A Jenkins slave mainly executes the jobs dispatched by the master.

Now that we know what a Jenkins master and Jenkins slaves do, here's how the Jenkins master and slave architecture works:

1. The Jenkins master schedules the build jobs.
2. The builds are then dispatched to the slaves or agents for execution.
3. The agents run tasks such as executing code and testing and deploying the code in various environments.
4. The master then monitors the slaves and records the build results.
5. The agents/slaves are taken online or offline when required.
6. The Jenkins master can also execute the jobs by itself.

What is a Jenkins pipeline?

A pipeline in software development is a series of multiple jobs or processes linked to each other and run in a sequence. Each stage in the pipeline takes an input, processes it according to the pre-set rules, and releases the output to the following stage. Jenkins's pipeline is a set of plugins that automate the CI/CD process. The pipeline is responsible for building codes, running tests, and deploying new software versions. The CI/CD pipeline of Jenkins includes the following stages:

1. Code commit and build.
2. Unit testing and integration testing.
3. Packaging and deployment.
4. Continuous feedback and notifications.

Continuous integration with Jenkins

Continuous integration is a practice that integrates code changes from different developers into a shared repository. It then triggers various tasks on the source code, such as build automation and test case automation for early detection of issues and bugs. The developers can then proceed and find solutions to remove these bugs and errors as quickly as possible, ensuring there are no software deployment delays.

Continuous deployment and continuous delivery with Jenkins

Continuous delivery is a phase where the code changes are all tested and made ready to be sent into the production environment through manual intervention. Continuous deployment on the other hand is a phase where the software is automatically deployed to production after passing all the tests. Jenkins automates the deployment of the codes by triggering deployment pipelines once the code passes integration and functional tests.

Here are some of the benefits of CI/CD

• Faster reaction times: Developers get immediate feedback on their code commits, making it easy to rectify any issues in the code as soon as possible. This also helps reduce human errors.
• Reduced code-integration risk: Frequent integration of smaller codes reduces the risk of larger and complex integration issues.
• Higher code quality: Constant review and constant testing of the code improves the quality of code.
• Faster deployment: Software can be pushed to production with minimal human intervention, ensuring faster delivery.
• Improved agility: Frequent and continuous deployment enables regular and smaller updates, ensuring quicker delivery.
• Minimized system downtime: Continuous and automated deployment ensures smooth rollouts, reducing downtime.

Real-time example: Github integration with Jenkins

Github is a popular source code repository. Integration with Github is the most commonly used setup in Jenkins CI/CD pipelines. When a developer pushes the code changes to Github repository, Jenkins triggers a series of build and test tasks automatically. Here's how the integration works:

1. The code commit or code change will be pushed by the developer to the Github repository.
2. Jenkins waits for the code and then pulls it from Github, triggering the build process.
3. The build includes integration tests, unit tests, and other necessary checks.
4. Jenkins then sends feedback (pass/fail) to Github and to other push notification tools, such as email or Slack.

The importance of Jenkins in the testing lifecycle

Jenkins is an important component in the software testing lifecycle because it automates testing tasks. Every time a code commit comes in, Jenkins triggers automated test scripts, ensuring testing occurs at all stages of the software deployment process. Manual testing without Jenkins is possible but is likely to be inefficient and will slow down the software development cycle. In manual testing, developers would need to trigger builds in-person, run tests, and analyze results, which is time-consuming and prone to human error. It's also difficult to identify issues with the code as quickly as in automated testing using Jenkins. Jenkins allows testing the code changes every time they're pushed to a version control system, making it agile and faster.

Advantages of using Jenkins for test automation

Jenkins is a boon for organizations as well as software developers in ensuring quality code is developed and deployed at a rapid speed. Jenkins provides several benefits when integrated for testing automation, such as:

• Flexibility: Integration with a huge variety of testing tools and frameworks such as selenium, Junit, Zoho QEngine, and so on.
• Scalability: Jenkins can be used on multiple machines with various operating systems, allowing parallel execution of tests and faster feedback.
• Supports various testing types: Jenkins can easily integrate with multiple testing tools and frameworks that support various testing types, such as unit, regression, and integration testing.
• Customized pipelines: Jenkins allows you to create customizable pipelines, allowing testers to facilitate cross-environment testing on web, mobile devices, APIs, etc. in parallel. This speeds up the testing process and enables quick deployment of the software version or features.
• Continuous monitoring: Jenkins continuously monitors the health of the codebase and automatically triggers tests when needed.
• Reporting: Jenkins can highlight failed tests and generate detailed test reports over time, making analysis easy.
• Customization: Jenkins can be customized to run different tests in different environments and different branches.

Jenkins and Zoho QEngine integration

Zoho QEngine is a test automation tool that supports running automated tests on mobile, web environments, and APIs. Integrating Jenkins with Zoho QEngine enables seamless test execution, automated reporting, faster identification and resolution of bugs in the code, parallel test execution, and efficient collaboration between developers and testers.

A typical scenario would include a software development team using Zoho QEngine for their testing automation. Here, each developer will push the code to a repository, and once the code commit is received, Jenkins triggers a series of activities such as build and automated tests through Zoho QEngine. After collecting the test results, Jenkins will notify the developer team if the tests fail or deploy the updated feature to a staging environment if everything is good.

Conclusion

Testers can benefit by integrating Jenkins with Zoho QEngine because this significantly improves the software quality, reduces manual errors, and ensures faster deployment and release of quality applications. With its extensive plugin system, vast community support, powerful pipeline capabilities, and robust integrations, Jenkins remains a key tool for organizations striving to achieve agility in software development.