Jenkins is an open-source, free server that allows testers and engineers to develop reliable technologies for Continuous Integration or flexible construction applications on systems that use Java for coding. It has over 1600 plugins to support any kind of development task.
Through various plugins, the Jenkins suite provides several benefits in software design, resulting in smoother validated procedures in the shortest amount of time. If no such plugin exists, one can build it and post it on the community website for more fine-tuning. Curious to know more about Jenkins interview questions and answers? Check out these Jenkins interview questions.
Jenkins interview questions and answers usually begin with simple inquiries about the product’s benefits, installation, and so on. After completing this package, you will have no difficulty in answering Jenkins interview questions. These Jenkins interview questions and answers are for experienced developers, testers, and advanced programmers. Always be succinct and to the point in the responses to Jenkins pipeline interview questions and answers.
These Jenkins interview questions and answers will boost your core interview skills and help you perform better. Be smarter with these Jenkins pipeline interview questions.
We have collected the questions in this set of Jenkins pipeline interview questions and answers after conducting extensive research and discussing with top Jenkins experts.
Let’s take a look at these 50 hand-picked Jenkins interview questions from the most prestigious companies:
Jenkins is a Continuous Integration platform that allows for the creation, testing, and implementation of new code. Continuous Integration (CI) is a mechanism in which developers commit updates to the source code from a common repository, and all improvements are created in real-time. This can happen many times a day. The CI server monitors each commitment in real-time, improving code builds and ensuring quick verification. This relieves the testers of their responsibilities, allowing for faster integration and less time wastage.
Jenkins has many appealing features for developers:
Jenkins is often used to consistently design and validate software applications. It makes it easy for developers to implement updates to the code and for users to get the latest version quickly. Jenkins uses plugins to accomplish Continuous Integration. Plugins essentially allow DevOps stages to be integrated.
Continuous Integration is a programming process that requires developers to commit updates to the source code in a public repository many times a day or at frequent intervals. A repository is created for any commitments made. As a result, any challenges can be spotted by the team early on. Moreover, the Continuous Integration platform performs various other tasks, such as deploying the development application to the test server, informing the relevant teams about the construct and test performance, etc. Jenkins uses plugins to accomplish Continuous Integration. Plugins generally allow DevOps stages to be integrated.
Buddy, Jenkins, TeamCity, Big Eval, GoCD, Bamboo, GitLab CI, and others are examples of continuous integration tools.
|Before Jenkins||After Jenkins|
|Once all of the developers had finished their allocated coding assignments, they would all commit the code at the very same time. Build is then reviewed and implemented.||As soon as the developer commits the code, it is designed and tested. Throughout the day, Jenkins will create and validate the code many times.|
|The development process is slow.||The development process moves quickly, and users now have easier access to new features. Profits are increased.|
Azure DevOps (formerly known as Visual Studio Team Services – VSTS) is a series of tools for creating, evaluating, and distributing software. Developing and installing software has become even more effective with Azure DevOps. It is not only a series of software for automating CI-CD using the Microsoft stack but it can also be conveniently integrated with a variety of other third-party tools.
Jenkins requires a few basic requirements to be installed on your Windows system.
The measures below should be taken to install Jenkins effectively:
The Jenkin suite’s essential plugins are Docker, Jira, Slack Notification, Maven, Amazon E2C, jUnit, Pipeline, Mailer, and Greenballs.
Jenkins uses a domain-specific language (DSL) called “Groovy” inside a Pipeline Project (read plugin), which will describe a new pipeline as just a script. That single script may articulate a flow that would typically take several “standard” Jenkins jobs chained around.
Groovy will work in conjunction with Java, and the two languages’ syntaxes are very close. While writing Groovy, when you forget the grammar, you can write in Java syntax. Groovy may be used as one of the Java platform’s scripting languages. Groovy scripts could be named from inside Java, reducing the amount of time spent on Java development.
Let’s assume a developer is operating on a code and contributes it to the repository.
The Jenkins Web application ARchive (WAR) file can be started from the command line in the following manner:
A pipeline is a set of interconnected jobs that are executed one after another in a predetermined order. Jenkins pipelines have several modules that can be used to combine and incorporate continuous deployment pipelines. Code is used to convey the directions to be followed.
Jenkins pipeline (or just “Pipeline”) is a collection of plugins that help you set up and use continuous distribution pipelines in Jenkins. A continuous distribution pipeline is an integrated representation of the product delivery process, from source code to consumers and customers.
There are 3 types:
Cron syntax is used for building a job in Jenkins. Cron syntax is represented by five asterisks, each separated by a space. The syntax is as follows – [minutes] [hours] [day of the month] [month] [day of the week]. For example, if you want to set up a Cron for every Monday at 11.59 pm, it would be 59 11 * * 1.
The steps for building a Jenkins job are as follows:
Due to various optimizations, Jenkins pipeline programs have become the tool of choice for business companies looking to incorporate and transform continuous distribution (CD) pipelines through Jenkins. CD pipelines are streamlined expressions of the mechanism for getting applications from version control to consumers and clients. Jenkins allows you to build CD pipelines using either a web UI or a Jenkins file that has been dedicated to source control.
Let’s pretend we want to use Node, a third-party tool.
|Open-source tool||Commercial tool|
|Supported by a huge global community||It has a separate production team|
|Not very user-friendly||More user-friendly features|
|There are several plugins available to execute different functions.||The majority of features are pre-installed, and there are also extensions available on the Atlassian marketplace.|
Jenkins uses plugins to simplify the whole continuous implementation and distribution process. The steps are as follows:
The JENKINS_HOME directory contains all of the settings, logs, and configurations.
Jenkins DSL (Domain Specific Language) is a plugin that allows jobs to be specified programmatically but in a human-readable manner. The UI settings are intuitively converted into code using this plugin. You’ll be able to build a version for the job while still keeping track of the updates. The translated code is written in the Groovy programming language.
The steps are as follows:
Blue Ocean is a contemporary Jenkins UI that provides a tailored interface with a modern style. Any user can build, diagnose, and simulate Continuous Delivery pipelines using this guide. Since it is viewed visually, there are no engineering qualifications required to build or comprehend the pipelines. Furthermore, since each stage can be quickly navigated, detecting automation problems is easy.
The steps are as follows:
The measures to combine Git with Jenkins are as follows:
We must first create a branch before we can create a CD workflow. The division is where all of the scriptings, checking, and code updates take place. If the research is over, the division modifications are combined and delivered.
Continuous Integration (CI) is the practice of continuously incorporating modifications into the essential program at all phases of the distribution pipeline after being validated in a prototype environment. Jenkins and Bamboo servers make use of CI.
Continuous Delivery is the manual delivery of code (shipping) to a specific test, integration, or manufacturing area.
Continuous Deployment is the automated release of code into the staging or development process after it has passed the CI stage’s testing.
Pipeline-as-a-code is a strategy or collection of features that allows you to keep the CI/CD workflow logic throughout the source code repository despite making extra Jenkins branch configurations. This is specific to projects with a Jenkins file folder in the repo’s root folder (containing a pipeline script). Declarative and syntax pipeline syntax are the two forms of pipeline syntax.
Jenkins is guided by the agent directive about how and when to conduct the Pipeline or its subsets. Agents are required for all pipelines. The agent creates a workspace for the pipeline, including source control checkout files and other required working files. When an executor is usable, it also triggers Jenkins to run the steps needed for execution.
Jenkins uses the continuous integration method, while Ant and Maven work on constructed software. Jenkins can run unit tests and deploy programs automatically, while Maven and Ant can only execute build operations.
Ant is a formal method, while Maven is a full declarative process with a lifecycle. Ant scripts cannot be reused. Maven modules, on the other hand, can be reused. Ant is an ancient technique that is now in use by legacy applications. Maven is used for the majority of new apps.
Jenkins manages project builds with the help of jobs. There are a few steps to setting up a job:
Jenkins can be secured and global protection configured by doing the following:
The agent determines the pipeline’s execution point for a specific stage or the whole pipeline.
Several input parameters may influence the execution of a construct. If you do have several test suites but just want to run one, for example. You can choose which one to run by setting a parameter. To use parameters in work, you must do so when specifying the parameter. The parameter may be a string, a register, or something else entirely.
There are two ways to start a node agent:
Browser: A JNLP (Java Web Start) file is downloaded if the Jenkins node agent is launched from a browser. This file starts a new job-running loop on the client computer.
Command-line: The executable agent.jar file is required to launch the node agent from the command line. When you run this file, it starts a loop on your client who communicates with Jenkins to create jobs.
Triggers determine where and how pipelines are operated.
This is a handy plugin that saves all of the important settings and parameters for future use. This is particularly helpful in case of a malfunction, as it prevents the settings from being lost.
There are two ways to fix a faulty construct:
Using the “restart from level” command, we can restart the pipeline from where it failed.
The JENKINS HOME (/var/lib/Jenkins) directory contains all of the configurations and parameters. The whole home directory should be copied to the new server. The command “sync” can be used to do this.
Maven is a platform for managing builds. All of the dependencies required to create, validate, and run the code can be configured using a simple pom.xml. Maven is in charge of a research project’s entire lifecycle. The Maven Webdriver can develop the project and run all tests effectively when it is merged with Jenkins.
Tools like Selenium or Maven can be used to run automated experiments. The developers can schedule the test runs. Jenkins shows the test results and gives the developers a note.
Git is software that allows you to trace improvements in a collection of files. It’s typically used to coordinate work by programmers working on source code together during software development. Pace, data consistency, and support for distributed, non-linear workflows are among its objectives (thousands of parallel branches running on different systems).
With the aid of a lightweight agent, a scripted Jenkins pipeline continues to run on the Jenkins ace. It makes use of a limited number of assets to interpret the pipeline into nuclear directions. Both declarative and scripted language structures are distinct from one another and are distinguished in unusual ways.
Jenkins’ default port is 8080.
The default port can be changed by using the CLI and running Java -jar Jenkins.war –httpPort=8282.
In the default directory, /etc/default/Jenkins, edit the text. And then restart with HTTP PORT=8001 set.
Jenkins supports the owner-slave model, in which a master employs a large number of slaves. Jenkins Distributed Builds is another name for it. It allows you to run jobs on a variety of platforms, including Linux, macOS, and Windows. We may also use Jenkins Distributed Builds to perform a similar project on several conditions in parallel, allowing you to achieve the best results quickly using this distributed approach. The rest of the task results are collected and analyzed on the master hub.
Jenkins has a built-in command-line interface that allows you to access it from the content of the shell. This is useful for automating repetitive errands, mass alerts, and inconvenience research, among other things. The Jenkins CLI client, which is a Java JAR file distributed with Jenkins, is used to use this interface.
With these Jenkins pipeline interview questions and answers and interview questions on Jenkins for testers, you will be able to ace your interview. Though not comprehensive, it lays the groundwork for impressing recruiters with your Jenkins skills. Jenkins is indeed a real-time tool for testing and combining mostly automated builds. It keeps track of a small version of a large Java code piece, culminating in system automation, which saves users and developers time.
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