What is Jenkins? How will it Help Create a Software Development Career?

Continuous Integration (CI) is an effective practice in learning software development techniques that involves regularly merging code changes prepared by multiple developers involved in a single project. They deploy all integrations or code changes in a shared repository. The main goal of CI is to ensure that each code change is integrated and tested as early and frequently as possible. The technique enables developers to identify and address integration issues, errors, or conflicts early in the development process. 

Hence, CI reduces the chance of encountering problems later on. It comprises various operations like code compilation, automated testing, quality checks, artifact generation, etc. Enterprises that opt for CI can improve collaboration, ensure code quality, catch and resolve integration issues early in the prototype stage, and accelerate the feedback loop.

CD is an engineering technique within DevOps. It concentrates on automating the software deployment process by delivering changes to production environments frequently and reliably. It expands the CI concept further by ensuring that the software is in the appropriate status for release or deployment at any given time. 

The deployment to the delivery pipeline goes through a series of stages, like building, testing, deploying, and delivery. Various operations involved in CD are deployment automation, configuration management, release orchestration, feedback monitoring, and management, etc.

In software development, CI and CD are utilized to automate various development processes by integrating code changes, testing, and deploying applications. As part of DevOps, CI/CD offers notable benefits to development teams and the organization. Let us explore them one by one:

Delivers Software Quickly 

Frequent and automated integration and deployments make it possible for developers to reduce time to market. The CI/CD pipelines can seamlessly transfer applications from the coding phase to the deployment phase. It ensures that the development speed corresponds to the needs of the client and company.

Enhances Software Quality

CI/CD facilitates continuous testing, feedback loops, and agile methodology for app development. It provides automated testing at different stages of the development pipeline. These testing phases detect bugs early, making it easier to resolve and isolate them. Lesser bugs ensure higher software quality. Also, with fewer errors or bugs in the app, the development cycle decreases the likelihood of release issues.

Facilitates Team Collaboration and Communication

During software development, collaboration plays a significant role in maintaining software quality and timely delivery. CI/CD streamlines smooth collaboration between the testing, development, designing, and operations teams. It helps each team member to communicate and resolve integration conflicts and issues promptly.

Reduces Risks of Defects

Finding and solving flaws in software development incurs unnecessary costs to the company. CI/CD allows for frequent integration and automated testing of code changes. It helps detect bugs, integration issues, and regressions early in software development. By identifying development problems early, developers can handle them promptly, reducing the time and effort required for troubleshooting later.

Increases Confidence and Reliability

CI/CD practices have another significant benefit, they give developers confidence about the software development process. By conducting automated tests and deploying changes consistently, software developers gain more trust in the code stability and reliability. The conviction allows them to repeat and experiment more freely.

Cost-effective Approach

In the competitive software market, time and assets are essential components that can make a product cost-effective. Since CI/CD pipeline takes a different route to software development, the errors get reduced in due time and the delivery becomes smooth. So, error-free projects with agile integration respond to client demands quickly and effectively, reducing time to market and the cost of resolving problems.

Jenkins is managed and built using a master-slave architecture. One Jenkins server cannot handle all the requirements necessary to develop and test the application. Hence, it needs multiple slaves to manage the same. The master and slave components intercommunicate with different slave units through Transmission Control Protocol (TCP) and Internet Protocol (IP). Here is how it all works. There are two components namely,

Jenkins Master

In the CI/CD pipeline, all the job scheduling (testing, deployment, delivery, etc.) gets carried out by the Jenkins master. It also handles numerous other tasks like dispatching builds to slaves for execution, recording, and presenting build results and monitoring all the slaves online/offline. Jenkins jobs are a collection of development assignments (used in the CI/CD pipeline) to build the source code, test your code, deploy the code, and run a shell script.

Jenkins Slaves

These are computing nodes that run on remote servers. They remain compatible with all different operating systems. These slave systems follow the request given by the Jenkins master. Building jobs dispatched by the master get run by the slave systems. Developers can configure how to run the project on a particular slave machine.

There are multiple essential Jenkins tools Jenkins-based developers must be familiar with.

Jenkins Plugins

Community developers usually develop plugins for Jenkins. Users who are using Jenkins can install these plugins on their Jenkins server. Jenkins plugins help developers and DevOps engineers with more functionality that is available in Jenkins. Suppose you want to use an S3 bucket to upload a file, you can install the AWS Jenkins plugin for the S3 bucket.

Jenkins Security

Authentication is another essential component of Jenkins. The primary authentication methods used in Jenkins are:

• LDAP Integration: Jenkins allows authentication using corporate Lightweight Directory Access Protocol (LDAP) configuration.
• Jenkins' User Database: It is a collection of users maintained by Jenkins' database. All the database maintenance is possible using the XML config files.
• SAML-based Single Sign On (SSO): Authentication based on the SSO technique is supported by Jenkins. It uses SSO providers like Okta, AzureAD, Auth0, etc.

Jenkins Nodes and Clouds

Jenkins developers can configure multiple agent nodes and cloud systems for running Jenkins jobs. The nodes use Linux or Windows operating systems, while the cloud uses Docker or Kubernetes to run Jenkins jobs on top of them.

Jenkins Credentials

To set up Jenkins pipelines, developers must connect their projects to a cloud account, an Application Programming Interface (API) endpoint through secret keys, and a database. During this connectivity scenario, users must save different types of secret keys and credential data such as username, password, Secure Shell (SSH) key, secret text, etc.

Jenkins Global Settings 

Jenkins global configuration has multiple other sub-configurations of installed plugins and native Jenkins Global configurations as well. Also, under this section, developers and engineers can configure global environment variables also.

Jenkins follows a series of steps or approaches to perform its deployment, testing, and delivery work.

Let us now understand how Jenkins’ elements interact with each other.

• As the developers commit changes to the source code, it gets placed in the repository.
• The Jenkins' Continuous Integration server reviews the code repositories at regular intervals. If any newly available code gets detected, it pulls the code.
• The Build Server is responsible for creating an executable version of the newly integrated code. If the test fails, the developers receive feedback about the issue.
• Then, Jenkins responsibly deploys the newly integrated version of the application to the test server. Developers get an alert notification if the test fails.
• If the code is free from errors, the tested application gets deployed on the production.

Aspirants who want to build projects using Jenkins or wish to learn Jenkins can undertake different jobs. The primary role of those well-versed with Jenkins is to help the development team reduce automated or repetitive software development tasks by incorporating CI/CD pipeline. Since Jenkins is a widely used DevOps tool, taking a DevOps course or learning Jenkins as a crash course can be an excellent start for beginners. Understanding the principles of DevOps and why Jenkins is necessary to enhance development can help aspirants get a good placement and salary package.

Other than basic graduation and post-graduation in computer science, some primary skills for Jenkins build, and release engineers are:  

• Build Management 
  Knowledge of how to manage project builds each time some new integrations happen is integral.
• Release Management
  CI/CD professionals should know when to release a final product and what testing phases the project should go through before release.
• Shell Scripting 
  Shell scripting is the process of writing and executing scripts using a shell. It is a command-line interpreter or interface to the operating system. Aspirants who want to leverage Jenkins for CI/CD must know shell scripting.
• Git or Other Version Control Systems
  Collaboration is a significant factor in the CI/CD process. Git is a distributed Version Control System (VCS) widely used in software development and collaborative projects. It allows multiple developers to work on the same codebase simultaneously.

• Jenkins Learn continuous integration DevOps with Jenkins: This advance-level course by Quickstart teaches importance of CI and DevOps in startups
• CI/CD with Jenkins X (LFS268): This course by The Linux Foundation is an intermediate-level course that teaches Jenkins X, an open source tool for CI. 
• Continuous Integration (CI) With Jenkins - Basic Build Jobs: This intermediate-level course by O’Reilly teaches using Jenkins automation server to build parameters. 
• Jenkins Certification Training Course: This course by Edureka is a beginner-level course focused on Jenkins pipeline, Tomcat 7, reporting, email and build plugins.
• Jenkins : Automating your delivery pipeline: This course is by Coursera that discusses topics like coding concept pipelines and the delivery system of Spring Pet Clinic.

Those qualified in using Jenkins can opt for the following careers:

DevOps Engineer 

They are responsible for bridging the gap between development teams and operations professionals. They use Jenkins to automate software builds, test cases, and deployment processes. They ensure a smooth integration and delivery of the application development process before deployment. The salary for DevOps engineers varies from country to country, as seen in the table below:

AWS DevOps Specialist

They specialize in implementing and managing DevOps practices using Amazon Web Services (AWS) cloud services. They understand AWS tools, CI/CD tools like Jenkins, DevOps services, and best practices for building, deploying, and operating applications. The salary for AWS DevOps specialists varies from country to country as seen in the table below:

Build Engineer

Build Engineers focus on project building and releasing. They also manage the integration teams and deployment process of software projects. They configure and maintain Jenkins jobs to automate the build process, run tests, and generate artifacts. The salary for Build engineers varies from country to country as seen in the table below:

Release Manager

Release Managers coordinate, plan, and deploy software releases. They utilize Jenkins for automating various project releases like building, packaging, and deploying applications to different environments. The salary for release managers varies from country to country as seen in the table below:

Software Engineer

Software Engineers set up Jenkins jobs for integrating new functionalities in builds, maintain code changes, run unit tests, and generate project artifacts for further deployment. The salary for software engineers familiar with Jenkins varies from country to country as seen in the table below:

Quality Assurance Engineer

The Quality Assurance (QA) Engineers utilize Jenkins for mechanizing various test executions. They use Jenkins for running different types of tests like integration tests, unit tests, and regression tests. QA engineers also generate reports based on test results. The salary for QA engineers with core knowledge of Jenkins usually depends on the company. The average salary of QA engineers across different countries are:

System Administrator

They leverage Jenkins for automating routine tasks, such as log analysis, system monitoring, and app build backup processes. They are also responsible for developing Jenkins jobs (using commands and scripts) for project monitoring and system maintenance.

The salary for system administrators who work closely with DevOps teams usually depends on the company. The average salary of system administrators across different countries are:

Like any other technology, Jenkins also has multiple benefits and drawbacks. Let us explore the advantages and disadvantages of Jenkins.

Advantages

• Jenkins is open-source, free of cost, and platform-independent. Hence, anyone can easily access it.
• Aspirants can install Jenkins on any operating system (Windows, MacOS, Linux, etc.) Also, it is excellent for cloud projects as professionals can deploy it on virtual machines.
• Jenkins offers to integrate multiple plugins for project builds, automation, testing, etc. It makes CI/CD implementation easy in projects. Some well-known plugins are the test analysis plugin, dashboard view plugin, build pipeline plugin, etc.
• Debugging through Jenkins is easy. Hence, developers and DevOps engineers do not have to go rigorously back and forth to fix application bugs.
• Jenkins enjoys excellent support from the developer community.

Disadvantages

• Jenkins can be complex to set up and configure, especially for new users who are beginners to CI/CD-based app development.
• In some situations, Jenkins may prove resource-intensive for application development; becoming heavier when handling large-scale projects or running multiple builds simultaneously.
• As Jenkins-based projects scale or evolve, maintaining and managing the infrastructure can become hectic and time-consuming.
• Jenkins primarily relies on a web-based interface, which can be less intuitive and user-friendly than modern CI/CD tools. It can lead aspirants and professionals to feel outdated and less polished, leading to a steeper learning curve for new aspirants learning Jenkins.
• The use of Jenkins also brings concern for DevOps engineers and developers. Jenkins security depends on proper configuration and management. If the cyber security associated with Jenkins is not set up correctly, it can lead to security risks. Sensitive data leakage and unauthorized access are among the top risks.

DevOps Jobs have spread across the software development realm, professionals are opting for CI and CD techniques using tools like Jenkins. This section will talk about the Unique Selling Points (USPs) and importance of Jenkins:

Distributed Architecture

Jenkins supports distributed builds, facilitating the execution of build processes across multiple machines and computing nodes. It allows the distribution of workloads, enhances performance, and scales the project based on demand.

Monitoring and Alerting

Jenkins comes with monitoring capabilities to track the status performance of software builds and deployments. It can trigger notifications, alerts, and generate logs depending on predefined conditions. This feature of Jenkins prevents project failures or bottlenecks.

Highly Customizable

Jenkins offers a greater degree of flexibility and customization. Aspirants and professionals can create and configure Jenkins jobs through its easy-to-understand web interface. This flexibility allows Jenkins to be tailored for specific project requirements and easy deployment.

Cost-Effective

Unlike other DevOps tools, Jenkins is an open-source tool. Hence, it is freely available. So, enterprises and aspirants who want to learn to use or implement them in large projects do not have to pay for the tool. That makes it an attractive option for organizations seeking cost-effective solutions without compromising functionality or performance.

Automated Testing

Jenkins facilitates automated testing. Aspirants and professionals can integrate popular testing frameworks and tools with its help. It can trigger test suites upon code changes, produce test reports, and provide visibility into test results, allowing teams to gauge code quality and recognize and fix problems promptly.

It is among the top open-source CI/CD tools enterprises use nowadays for automated integration, testing and deployment of project builds. Thus, aspirants who want to become DevOps engineers or DevOps cloud engineers, system administrators, build engineers, can learn Jenkins to stay ahead in the competitive job market.

Those looking to learn Jenkins can explore online self-paced courses from sites like Careervira. which has an excellent archive of industry-standard courses on Jenkins and other DevOps tools.