“Industry Use Cases OF Jenkins🤵…!!”

Hey Folks, If you wants to know about jenkins & its use cases, Then bingo…you are on the right page..!!

Lets discuss what is jenkins??

Continuous Integration & Continuous Delivery are integral parts of DevOps, as they are used for integrating multiple stages of the methodology. There are many CI/CD tools in the market but Jenkins; the Java-based open-source CI/CD tool tops the popularity list.

In this blog as we try to answer ‘what is Jenkins’, we also deep dive into what is Jenkins pipeline, how does Jenkins work, and more.

Jenkins is an open-source server that is written entirely in Java. It lets you execute a series of actions to achieve the continuous integration process, that too in an automated fashion.

This CI server runs in servlet containers such as Apache Tomcat. Jenkins facilitates continuous integration and continuous delivery in software projects by automating parts related to build, test, and deployment. This makes it easy for developers to continuously work on the betterment of the product by integrating changes to the project.

Jenkins automates the software builds in a continuous manner and lets the developers know about the errors at an early stage. A strong Jenkins community is one of the prime reasons for its popularity. Jenkins is not only extensible but also has a thriving plugin ecosystem.

History Of Jenkins

Jenkins has an early mover advantage since it has been in development since 2011. Kohsuke Kawaguchi created Jenkins (then called ‘Hudson’) while working at Sun Microsystems. Hudson was created in summer 2004 and the first release was in February 2005.

After the acquisition of Sun Microsystems by Oracle, a proposal was approved by the Hudson community for creating the Jenkins project. In February 2011, Oracle intended that the development of Hudson should continue hence, Hudson was forked instead of renaming it to Jenkins.

Though Hudson and Jenkins were being developed independently, Jenkins acquired significantly more projects & contributors than Hudson. Consequently, Hudson is no longer maintained by the community

Salient Features Of Jenkins:

1. Easy Installation & Configuration

Jenkins is a self-contained Java program that is agnostic of the platform on which it is installed. It is available for almost all the popular operating systems such as Windows, different flavors of Unix, and Mac OS.

2. Open-Source

As it is open-source, it is free for use. There is a strong involvement of the community which makes it a powerful CI/CD tool.

3. Thriving Plugin Ecosystem

The backbone of Jenkins is the community and the community members have been instrumental in the development (and testing) of close to 1500+ plugins available

4. Easy Distribution

Jenkins is designed in such a manner that makes it relatively easy to distribute work across multiple machines and platforms for accelerated build, testing, and deployment.

How Does Jenkins Work?

In this section of the What is Jenkins blog, we look at the internal functioning of Jenkins i.e. what happens once the developer commits changes to the repository and how CI/CD is realized in Jenkins. We also look at the Master-Agent architecture in Jenkins.

Architecture Of Jenkins

Before we dive into how does Jenkins work, we must understand the architecture of Jenkins. These are the series of steps that outlines the interaction between different elements in Jenkins:

• Developers do the necessary modifications in the source code and commit the changes to the repository. A new version of that file will be created in the version control system that is used for maintaining the repository of source code.
• The repository is continuously checked by Jenkins CI server for any changes (either in the form of code or libraries) and changes are pulled by the server.
• In the next step, we ensure that the build with the ‘pulled changes’ is going through or not. The Build server performs a build with the code and an executable is generated if the build process is successful. In case of a build failure, an automated email with a link to build logs and other build artifacts is sent to the developer.
• In case of a successful build, the built application (or executable) is deployed to the test server. This step helps in realizing continuous testing where the newly built executable goes through a series of automated tests. Developers are alerted in case the changes have caused any breakage in functionality.
• If there are no build, integration, and testing issues with the checked-in code, the changes and tested application are automatically deployed to the Prod/Production server.

Here is the diagrammatic representation of the Jenkins architecture:

A single Jenkins server might not be sufficient to realize the following requirements:

• Testing needs to be performed on different environments (i.e. code written using different languages e.g. Java, Python, C, etc. are committed to the version control system), where a single server might not suffice the requirement.
• A single Jenkins server might not be sufficient to handle the load that comes with large-scale software projects.

In such scenarios, the distributed (or Master-Agent) architecture of Jenkins is used for continuous integration and testing. Diving deeper into how does Jenkins works, we take a look at the architecture of Jenkins.

Master- Agent Architecture In Jenkins

The master-agent (or distributed) architecture in Jenkins is used for managing distributed builds. The Master and Agent(s) communicate through the TCP/IP protocol.

These are the roles and responsibilities of the Jenkins Master and Agent(s):

Jenkins Master

The main server in Jenkins is the Master. Here are the jobs handled by Jenkins Master:

• Schedule build jobs
• Choosing the appropriate agent in the master-agent ecosystem for dispatching the builds.
• Monitor agents and take them online/offline as and when required.
• Presenting the build results (and reports) to the developer.

The Jenkins master can also execute the jobs directly but it is always recommended to select the appropriate agent(s) for build and execution-related tasks.

Jenkins Agent(s)

A agent is a remote machine that is connected to the Master. Depending on the project and build requirements, you could opt for ’N’ number of agents. agents can run on different operating systems and depending on the ‘type of build request’, the appropriate Agent is chosen by the Master for build execution and testing.

Here are the jobs handled by the Jenkins Agent(s):

• Listen to commands from the Jenkins Master.
• Execute build jobs that are dispatched by the Master.
• Developers have the flexibility to run the build and execute tests on a particular agent or a particular type of Agent. The default option is Jenkins Master selecting the best-suited Agent for the job.

Here is a simple diagrammatic representation of how does Jenkins work, with multiple Jenkins Agents connected to the Jenkins Master:

In the Jenkins Master-Agent architecture shown below, there are three Agents, each running on a different operating system (i.e. Windows 10, Linux, and Mac OS).

• Developers check-in their respective code changes in ‘The Remote Source Code Repository’ that is depicted on the left-hand side.
• Only the Jenkins master is connected to the repository and it checks for code-changes (in the repository) at periodic intervals. All the Jenkins Agents are connected to the Jenkins Master.
• Jenkins master dispatches the request (for build and test) to the appropriate Jenkins Agent depending on the environment required for performing the build. This lets you perform builds and execute tests in different environments across the entire architecture.
• The Agent performs the testing, generates test reports, and sends the same to the Jenkins Master for monitoring.

As developers keep pushing code, Jenkins Agents can run different builds versions of the code for different platforms. Jenkins Master (or Master Node) controls how the respective builds should operate.

Important Concepts Of Jenkins Pipeline

Moving on with what is Jenkins pipeline, here are some basic concepts that need to be well-understood if you are planning to use the Jenkins Pipeline:

a. Pipeline

The Pipeline consists of a set of instructions written as code. It defines the entire build process, which ideally consists of different stages for building, testing, and delivering the application.

b. Node

Node is a machine that is a part of the Jenkins environment. The Jenkins Pipeline executes on a node block that is usually a part of the Scripted Pipeline syntax.

c. Stage

Stage in a Jenkins Pipeline consists of a unique subset of tasks such as Build, Test, Deploy, etc. The Stage block is used by many plugins for providing the visualization of Jenkins status (and progress).

d. Step

Step is a single task that tells Jenkins what exactly needs to be done. For example, setting an environment variable can be done in a step, executing a build command can also be a step. On the whole, a Jenkins Pipeline constitutes a series of steps.

Advantages Of Using Jenkins Pipeline

Jenkins Pipeline is instrumental in adding a rich set of automation tools onto Jenkins. Hence, Jenkins can be used for simple continuous integration as well as for comprehensive CD pipelines.

These are some of the primary reasons for using the Jenkins Pipeline:

• As the Jenkins Pipeline is implemented as code, it can be checked in the source control repository. Teams can view, edit, as well as iterate upon the delivery pipeline.

• Jenkins Pipelines are robust. A Pipeline is automatically resumed in case the server witnesses an unplanned restart.
• Pipeline process can pause and wait for input for any input from the user.
• Pipelines are versatile as they can be used for realizing complex CD requirements, including performing work in parallel.
• Jenkins Pipelines are extensible by plugin developers and users with Pipeline Shared Libraries.

Jenkins Case Study:

Lets see “How Jenkins helped Avoris Travel“..

A fast, simple CI/CD matters when your technology is
the driver for a new kind of travel company

👉Avoris. Reinventing Travel :

Ávoris is an innovative project, open to new ideas, driven by digital transformation, committed to excellence and quality, and the undisputed protagonist of the current tourism universe.

A great global tour operator that from Spain and Portugal with a determined spirit of internationalization, has consolidated its presence in 15 Latin American countries and extended its roots to the entire planet: from Asia, through China, to North America, with Miami as the gateway. input.

“Our infrastructure is very important because we have to be online to meet customer demand anywhere in the world,” said Alejandro Alvarez Vazquez, Sysadmin, Avoris Travel. “Our CI/CD platform is used by 200 people. The services that we build and deploy are used by thousands of potential clients and by our network of 675 own agencies located in Spain and Portugal.”

A use case for acceleration while reducing build times by more than half

Process improvement is top of mind for the ops team at Avoris. And Alejandro shared his story for one critical instance where the use of Jenkins made a big difference.

They realized their build times were on the decline, so they sought to minimize their delivery cycle times with Jenkins. The results? The team was able to speed up their CI/CD with shared volumes and more. And they were able to reduce build times more than 50%.

✋Challenge:

With over 200 developers relying on the company’s infrastructure, they needed a secure, easily customizable, and powerful CI/CD platform.

👉Solution:

Avoris Travel, a unique travel company seeking to reinvent the travel industry, relies on an equally inventive technology platform fueled by Jenkins.

👉Results:

1. reduced build times over 50% with the flexibility of Jenkins plugins.
2. increased the speed of delivery with Jenkins Pipelines.
3. Much less problematic and simple deployments for the team.
4. scalable infrastructure supporting 675 agencies and over 2.8 million international consumers.

Thanks for reading…!

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