What is Jenkins?
Jenkins is an open-source continuous integration/continuous delivery and deployment (CI/CD) automation software DevOps tool written within the Java programing language. it’s wont to implement CI/CD workflows, called pipelines. Pipelines automate testing and reporting on isolated changes during a larger code base in real-time and facilitate the mixing of disparate branches of the code into the main branch. They also rapidly detect defects during a codebase, build the software, automate testing of their builds, prepare the code base for deployment (delivery), and ultimately deploy code to containers and virtual machines, also as bare metal and cloud servers. There are several commercial versions of it. This definition only describes the upstream open source project.
Jenkins to the rescue! As an endless Integration tool, it allows seamless, ongoing development, testing, and deployment of newly created code. Continuous Integration may be a process wherein developers commit changes to the development code from a shared repository, and every one of the changes to the development code is built continuously.
The Jenkins project was started in 2004 (originally called Hudson) by Kohsuke Kawaguchi, while he worked for Sun Microsystems. Kohsuke was a developer at Sun and got uninterested in incurring the wrath of his team whenever his code broke the build. He created Jenkins as how to perform continuous integration – that’s, to check his code before he did an actual plan to the repository, to make certain all was well. Once his teammates saw what he was doing, all of them wanted to use it. Kohsuke open-sourced it, creating the Jenkins project, and shortly Jenkins usage had spread around the world.
How Jenkins works:
Jenkins is distributed as a WAR archive and as installer packages for the main operating systems, as a Homebrew package, as a Docker image, and as a development code. The development code is usually Java, with a couple of Groovy, Ruby, and Antlr files.
You can run the WAR standalone or as a servlet during a Java application server like Tomcat. In either case, it produces an internet interface and accepts calls to its REST API.
When you run it for the primary time, it creates an admin user with an extended random password, which used for its initial webpage to unlock the installation.
it offers many great features for developers:
Free Open Source: it is an open-source resource supported by full community support.
Easy Installation: it may be a platform-agnostic, self-contained Java-based program, able to run with packages for Windows, Mac OS, and Unix-like operating systems.
Easy Configuration: it is found out and configured using its web interface, featuring error checks and a built-in help function.
Extensible: it is often extended through its plugin architecture, providing nearly endless possibilities for what it can do.
Available Plugins: There are many plugins available within the Update Center, integrating with every tool within the CI and CD toolchain.
Easy Distribution: it easily allocate work across multiple machines for quick builds, tests, and deployments across multiple platforms.
Advantages and Disadvantages:
There are pros and cons to it.
One of the benefits of it is that it is often extended using plugins. This makes it adaptable to changes in IT environments. Plugins also contribute to the flexibility of Jenkins, as does the rich scripting and declarative languages that leave highly custom pipelines. Since Jenkins is very unopinionated, it fits well into most of the environments, including complex hybrid and multi-cloud systems.
Jenkins has been around for much longer than other solutions during this space. This, plus its flexibility, has led thereto being widely deployed. For this reason, Jenkins is well understood, with a broad knowledge domain, extensive documentation, and abundant community resources. These resources make it easier to put in, manage, and troubleshoot Jenkins installation.
Jenkins and its plugins are built on Java. Java may be a proven enterprise development language with a broad ecosystem. This places it on a solid base which will be extended using common design patterns and frameworks.
Jenkins is, obviously, not perfect. While it’s easy to put in, production Jenkins is often difficult to implement. Developing production pipelines using Jenkins files requires coding in either its declarative or scripting language. Complex pipelines, particularly, are often difficult to code, debug, and maintain.
The open-source system is one server architecture. This makes it easy to put in but caps resources to those of one computer, virtual machine, or container. it doesn’t leave federation across servers leading to performance issues. Lack of federation also can cause a proliferation of independent Jenkins servers that are difficult to manage across an outsized enterprise.
it is dependent on older Java architectures and technology, specific as servlets and Maven. Even the Jenkins Docker installation still requires that the Jenkins code and servlet middleware be packaged into a container together, maintaining its monolithic architecture. additionally, it’s not designed to be implemented using newer Java technology like Spring Boot or GraalVM.
Before and After Jenkins
|Before Jenkins||After Jenkins|
|The entire development code of the project was built then tested. The application bugs identification and fixing within the event of build and test failure was problematic and time-consuming, which sequentially slows the software delivery process.||Every commit made within the development code is built and tested. So, instead of checking the entire development code developers only got to specialize in a specific commit. This results in normal new software releases.|
|The developers need to await test results.||The developers know the test results of every commit made within the development code on the run.|
|The full build, test, deployment process is manual.||The developers only got to commit changes to the development code and Jenkins will automate the remainder and notifications of the method required.|
it provides developers with a superb framework from which they will develop and test new codes, leading to the quicker delivery of complex quality software. By avoiding costly delays and log roadblocks. Jenkins offers an easy CI/CD environment for just about any combination of languages and development source code repositories using pipelines, also as automating a variety of other routine development tasks. While Jenkins doesn’t eliminate the necessity to make scripts for individual steps, it does offer you quicker and more forceful to integrate the entire chain of build, test, and deployment tools than you’ll easily build.