Are you looking for a career in development and operations roles in the IT industry? Well, then the future is yours. Currently, DevOps has a huge popularity worldwide and more than 50% of the organizations are implementing DevOps as per Forrester research. The career opportunities for DevOps professionals are booming with high payouts in the industry. The average annual salary of DevOps professionals ranges around $136,300.

However, cracking the DevOps interview is not easy and requires a lot of preparation. To help you out, we have collected the Top DevOps Interview Questions which are crafted by industry experts, and they will surely help you progress forward in DevOps development.

For your better understanding, we have segregated the DevOps interview questions into:

Let’s not waste much time and get started.

DevOps Basic Interview Questions

Q1. Define DevOps.

Ans. DevOps can be defined as a combination of software development practices and tools used for increasing organizations' ability while delivering applications, services, and more in close alignment with business objectives.

Q2. Why DevOps is Important?

Ans. The major reasons to adopt DevOps are listed below:

  • Faster innovations
  • Shorter development cycles
  • Reduced deployment failures
  • Improved communication and collaboration
  • More stable operating environments
  • Increased efficiencies
  • Reduced Costs and IT Headcount

Q3. What is the difference between Agile and DevOps?

Ans. The major differences between Agile and DevOps are listed below:

Description Agile DevOps
Definition It's an iterative approach that focuses on development. It's a practice of both development and operations.
Purpose Manages complex projects. Manages end-to-end engineering processes.
Target areas Software development. End to end business solutions and faster deliveries.
Tools Kanboard, JIRA, and Bugzilla are popular Agile tools. AWS, Puppet, Chef are some popular DevOps tools.
Release cycles Supports Agile release Cycles Shorter release cycles and also supports defect detection.
Feedback source Self-feedback Feedback from customers.

Q4. List the core operations of DevOps for application development and infrastructure.

Ans. The core operations of DevOps for application development and infrastructure are listed below:

Application development

  • Code building
  • Code coverage
  • Unit testing
  • Packaging
  • Deployment

Infrastructure

  • Provisioning
  • Configuration
  • Orchestration
  • Deployment

Q5. Which are the most popular DevOps tools?

Ans. The most popular DevOps tools are listed below:

  • Git: Version Control System tool
  • Jenkins: Continuous Integration tool
  • Docker: Containerization tool
  • Puppet: Configuration Management and Deployment tools
  • Ansible: Configuration Management and Deployment tool
  • Nagios: Continuous Monitoring tool

Get in-depth knowledge on DevOps Configuration Tools

Q6. What are DevOps key performance indicators?

Ans. The following are the DevOps key performance indicators (KPIs):

  • Deployment Frequency
  • Deployment Failure
  • Change Lead Time
  • Change Volume
  • Mean Time To Detection
  • Mean Time Between Failures
  • Mean Time To Recovery
  • Change Failure Rate
  • Efficiency
  • Performance
  • Pipeline Adoption

Q7. List the key components of DevOps.

Ans. The following are the key components of DevOps:

  • Continuous Integration
  • Continuous Delivery
  • Microservices
  • Infrastructure as Code
  • Monitoring and Logging
  • Communication and Collaboration

Checkout DevOps Tutorial

Version control system (VCS) Interview Questions

Q8. What is the version control system (VCS) in DevOps?

Ans. A version control system is also known as a source control system, and it records the changes done to a file or a set of files over time. It consists of a central shared repository where developers can collaborate on code and track changes.

Q9. What are the benefits of version control?

Ans. The primary benefits you can expect from a version control system are the following:

  • Complete long-term change history of every file is available.
  • All the past versions and variants are kept independent from each other inside the VCS through branching, and whenever required, you can merge back together with the file’s content to verify the changes. 

Q10. What is a branching strategy in DevOps?

Ans. Branching is a technique employed for code isolation. In simple terms, it makes a copy of the source code to create two versions that are developed separately. There are various types of branching available. Therefore, the DevOps team must make a choice depending on application requirements. This choice is called a branching strategy.

Q11. What is Git?

Ans. Git is a distributed version control system particularly used for recording the changes in the source code during software development. It manages a set of files or a project that change over time. It stores the information in a data structure called repository.

Let's understand the importance of Git through its benefits to organizations:

  • Feature branch workflow
  • Distributed development
  • Pull requests
  • Data redundancy and replication
  • High availability
  • Superior disk utilization and network performance
  • Collaboration friendly

Q12. What are the top Git commands?

Ans.

Command Usage Description
git config git config –global user.the name “[name]” This command sets the author name to be used with your commit.
git init git init [repository name] This command starts a new repository.
git clone git clone [url] This command is used for obtaining a repository from an existing URL.
git add git add [file] This command adds a file to the staging area
git commit git commit -m “[ Type in the commit message]” This command records/snapshots the file permanently in the version history
git status git status This command lists all the files that have to be committed.
git rm git rm [file] This command deletes the file from your working directory and stages the deletion.

Continuous Integration Interview Questions

Q13. What’s the main purpose of Continuous Integration (CI)?

Ans. Continuous integration is a development practice of automating the integration of code changes from several contributors to a single software project. By regularly integrating, you can detect errors quickly and locate them easily. The source code version control is the crux of the CI process.

Q14. What are the benefits of Continuous Integration?

Ans. The major benefits of Continuous Integration are listed below:

  • Faster development cycles
  • Smarter risk mitigation
  • Stable codes
  • Team Communication
  • Reduced Overhead
  • Flexibility 
  • Consistency of Build Process

Q15. What is Trunk-Based development? 

Ans. A Trunk-Based development is a source control branching model for software development where developers associate on code in a single branch called trunk and employ documented techniques to create long-lived development branches. This process is called Trunk-Based development. It is a key enabler of continuous integration and by extension continuous delivery.

Q16. How to create a backup and copy files in Jenkins?

Ans. The following steps will help you understand how to create a backup and copy files in Jenkins:

  • Periodically backup your JENKINS_HOME directory, which contains job configurations, slave node configurations, and all your build history.
  • To create a back-up of your Jenkins setup, just copy this directory. You can also copy a job directory to clone or replicate a job or rename the directory.

Q17. How to move or copy Jenkins from one server to another?

Ans. There are multiple ways to copy or move Jenkins from one server to another:

  1. Move a job from one installation of Jenkins to another by simply copying the corresponding job directory.
  2. Make a copy of an existing job by making a clone of a job directory by a different name.
  3. Rename an existing job by renaming a directory. Note that if you change a job name you will need to change any other job that tries to call the renamed job.

Q18. How to create a new build job in Jenkins?

Ans. The following steps will help you understand how to create a Jenkins job:

  • Step1: Logon to the Jenkins dashboard and click on the new item at the top left side of the dashboard.
  • Step2: Enter the item name and click on the freestyle project.
  • Step3: Enter the details of the project you want to test.
  • Step4: Enter your repository URL under source code management.
  • Step5: Under the build, click on add build step, and click on execute Windows batch command.
  • Step6: After entering the data, click on apply and save the project. 
  • Step7: Click on Build now button to build the source code.
  • Step8: To see the status of the build you run, click on the build number and click on the console output.

 Q19. List the top jenkins plugins.

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Ans. There are many useful plugins in Jenkins. Here, I have listed a few of the top plugins used in Jenkins.

  • Dashboard view plugin
  • Performance plugin
  • Kubernetes plugin
  • Amazon ECS Container Service
  • Git plugin
  • Monitoring plugin

Continuous Testing Interview Questions

Q20. What is Continuous Testing? Explain its benefits.

Ans. Continuous Testing is defined as a process of executing automated tests as part of the software delivery lifecycle to obtain feedback on business risks associated with the software release. The objective of continuous testing is to test early and test often to prevent the problems from progressing to the next stage of the SDLC.

The benefits of Continuous Testing are listed below:

  • Mitigates business risks.
  • Improves code quality.
  • Agile and reliable process.
  • Provides test environment access with service virtualization.
  • Maintains consistency through the same configuration for all the tests.

Q21. What do you mean by Automation Testing? 

Ans. Automation Testing or Test Automation is a software testing technique. It is used to automate the testing tasks and repetitive tasks which are difficult to perform manually. It involves the use of separate testing tools which lets you create test scripts to test and compare the actual and expected outcomes.

Q22. What are the benefits of Automation Testing?

Ans.  The major benefits of automation testing are listed below:

  • Supports wider test coverage of application features
  • Ensures consistency
  • Allows parallel execution
  • Improves efficiency
  • Reusable test scripts
  • Saves money and time
  • Reliable results

Q23. List the best Continuous Testing tools?

Ans. The following are the best Continuous Testing tools:

  • Selenium
  • Travis
  • QuerySurge
  • Experitest
  • TestRail

Q24. Mention the testing types supported by Selenium?

Ans.  Selenium supports functional testing and regression testing.

  • Functional Testing: It verifies each function of the software application against the functional specifications/requirements.
  • Regression Testing: In this, test cases are re-executed to verify the previous functionality of the application.

Q25. How to launch the Browser using WebDriver?

Ans. 

  • For Firefox:
WebDriver driver = new FirefoxDriver();
  • For Chrome:
WebDriver driver = new ChromeDriver();
  • For Internet Explorer (IE):
WebDriver driver = new InternetExplorerDriver();

Q26. What’s the difference between Continuous Delivery and Continuous Deployment?

Ans.

Continuous Delivery: It is a process in which continuous integration, automated testing, and automated deployment capabilities develop, build, test, and release high-quality software rapidly and reliably with minimal manual overhead.

Continuous Deployment: It is a process in which qualified changes in the architecture or software code are deployed automatically to production as soon as they are ready and without human intervention.

Configuration Management Interview Questions

Q27. What is the objective of Configuration Management?

Ans.

  • The objective of Continuous Management is to manage all the configurations of the SDLC by making development/deployment process controllable and reliable to provide high-quality software.
  • There are various components in a configuration management system such as servers, networking, storage, and software. The main purpose of configuration management is to make sure the target systems and software are in the desired state.

Q28. Which are the best configuration management tools?

Ans. The best Configuration Management tools are mentioned below:

  • Chef - Automation platform that transforms infrastructure into code.
  • Ansible - Automates entire IT infrastructure.
  • Puppet - Open-source configuration management tool.
  • Saltstack - It is based on Python programming language and allows scalable and efficient configuration.
  • CFEngine - Open-source configuration management tool, which automates large scale and complex IT infrastructure.

You can also mention any other tools if you have real-time experience in your previous job and explain how it improves the software development process.

Q29. Why is Infrastructure as code important? 

Ans. 

  • Infrastructure as code (IaC) is a method to manage and provision IT infrastructure (networks, databases, connection topology, etc.) through source code, rather than manual process or interactive configuration tools.
  • It helps you to automate the infrastructure deployment process easily, consistently, and reliably.

Q30. How does configuration management differ from provisioning infrastructure?

Ans. Configuration management and provisioning infrastructure, both are important for DevOps toolchain. While configuration management is best when it comes to employing desired configurations for target machines or group of machines, provisioning helps you to create, modify, delete, and track infrastructure using APIs or code.

Q31. What is Puppet?

Ans. Puppet is an open-source configuration management tool used for deploying, configuring, and managing servers. It follows a client-server architecture, in which the client is agent and server is known as the master.

Puppet agent and master communicates through a secure encrypted channel with the help of SSL.

Q32. What is a Puppet Manifest?

Ans. Puppet Manifest is a base component for Puppet configuration management policy. In Puppet Master, each Puppet node or Puppet Agent has its configuration details written in the native Puppet language. The details that are written in a language that puppet can understand and describe how resources should be configured are termed as Puppet manifests.

Puppet Manifests declares resources that define state to be enforced on a node. They are considered to be building blocks for complex Puppet modules.

Q33. How Puppet Module is different from Puppet Manifests?

Ans. Puppet Module is a bundle of manifests and data. They have a specific directory structure which allows Puppet to automatically load classes, facts, custom types, defined types, and tasks. Modules must have a valid name and are installed in Puppet’s module path.

Puppet Manifests are nothing but Puppet programs which are composed of Puppet code. It uses.PP extension.

Q34. Explain Puppet Codedir.

Ans. Puppet Codedir is the main directory for Puppet code and data and is mostly used Puppet master and Puppetapply. It consists of global modules directory, Hiera data, and environments (which consists of your manifests and modules).

The Codedir will be located in one of the following locations:

  • Unix:
/etc/puppetlabs/code

Unix non-root users:

 ~/.puppetlabs/etc/code
  • Windows:
 %PROGRAMDATA%PuppetLabscode 

Q35. How can you configure systems with Puppet?

Ans. You can configure systems with Puppet in two ways: 

  • In client or server architecture, you should use the Puppet Agent and Puppet Master.
  • In stand-alone architecture, you should use the Puppet apply application.

Q36. What is Factor in Puppet? How does it work?

Ans. The factor is Puppet’s cross-platform system profiling library. Puppet uses factor to gather information during Puppet run.

Factor discovers and reports basic information of Puppet Agent including network settings, IP addresses, hardware details, etc., and makes available in Puppet manifests as variables.

Q37. How does Ansible work?

Ans. Ansible is an open-source automation tool. It operates by connecting to your nodes and pushing out small programs called Ansible modules to them. It executes these modules through SSH by default and removes them when finished.

It handles many nodes from a single system over an SSH connection by using Ansible playbooks. These Playbooks are capable to execute multiple tasks and represented in YAML format.

Q38. How Ansible playbook is different from ad-hoc commands?

Ans. 

  • Ansible playbook is a structured unit of scripts that describes work for server configuration. It is used for repeated actions.
  • An ad-hoc command is used to do something quicker, mostly one-time use.

Q39. How to get a list of Ansible predefined variables?

Ans. Ansible stores facts about machines under management by default and these can be accessed in playbooks and templates. To get a list of all the facts that are available about a machine, run a setup module as an ad-hoc action: 

Ansible -m setup hostname

This will present all the facts that are available under that particular host.

Q40. What are Ansible Handlers?

Ans.  Handlers are exactly like regular tasks inside an Ansible playbook but run only when the task contains notify directive and also additional information if it changes something.

Eg: When a config file was changed, the task referencing that config file notifies service restart handler.

Q41. How does Chef work?

Ans. Start your answer with defining Chef. It is an automation platform that is particularly used for transforming infrastructure into code. It uses pure-Ruby domain-specific language to write system configurations.

Now you can explain the architecture of Chef and how it works.

Chef architecture consists of three core components:

Chef Workstation, Chef Node, and Chef Servers.

  • Chef Server: Chef Server is the core point for infrastructure’s configuration data. It stores, configures, manages, and presents the configuration data to all components.
  • Chef Workstation: Workstations are the hosts where you can create, test, and modify your cookbooks and configuration data.
  • Chef Node: These are the servers managed by the Chef. Chef client is installed on each node which is under management by Chef. Chef clients run on the nodes to contact the chef server for the information required to configure the node.

Q42. Explain Chef Resources.

Ans. First, begin with the definition of a Chef Resource. A Chef Resource describes a piece of an operating system at its desired state. It is a configuration policy statement that is used for representing the desired state of a node to which you want to take the current configuration for using the resource providers.

The functions of a Chef Resource are listed below:

  • It helps to know the present status of the target machine.
  • Defines the steps needed to perform for getting the target machine to the desired state.
  • Specifies resource type such as template, package, file, or service.

Q43. How Chef CookBook is different from Chef Recipe?

Ans.

  • A Chef Recipe is a set of resources that primarily configures a software package or some piece of infrastructure. Recipes are written in Ruby language.
  • While a Chef Cookbook consists of recipes that a node desired state.

Q44. What happens when you don’t specify a Resource’s action in Chef?

Ans. In case, if you don't specify a resource’s action, then Chef applies the default action.

For example, in resource 1, the action is not specified, still, it will take a default action.

file 'C:UsersAdministratorchef-reposettings.ini' do

content 'greeting=hello world'

end

In resource 2, when you define the action with create command, it is also used to create the default action.

file 'C:UsersAdministratorchef-reposettings.ini' do

action :create

content 'greeting=hello world'

end

Q45. How to refresh static components of a deployed application without redeploying the entire application?

Ans. By using Weblogic.Deployer you can define a component and target a server through the following syntax:

java weblogic.Deployer -adminurl http://admin:7001 -name appname -targets server1,server2 -deploy jsps/*.jsp

Q46. How to turn off the auto-deployment feature?

Ans. The auto-deployment feature is used for determining whether there are any new applications or changes in existing applications and dynamically deploy them.

It is enabled for servers that run in development mode.

To turn off the auto-deployment feature, follow one of the methods to place servers in production mode:

  • In the Administration Console, click the name of the domain in the left pane and select the Production Mode checkbox in the right pane.
  • At the command line, include the following argument when starting the domain’s Administration Server:
-Dweblogic.ProductionModeEnabled=true
  • Production mode is set for all WebLogic Server instances in a given domain.

Continuous Monitoring Interview Questions

Q47. Why is Continuous Monitoring important?

Ans. Continuous Monitoring helps to detect and measure the security implications for planned and unexpected changes and assesses the vulnerabilities in a threat space.

It delivers information on the application’s performance and usage patterns.

Q48. Which are the best Continuous Monitoring tools?

Ans. The following are the best Continuous Monitoring tools:

  • Nagios
  • Tenable
  • Solarwinds
  • Lansweeper
  • Spiceworks
  • Snort

Find more similar monitoring tools: DevOps Monitoring Tools

Container Interview Questions

Q49. What are Containers and list their benefits?

Ans. A Container is an operating system virtualization. A single container can be used to run anything from a staging environment into production. It consists of an entire run-time environment such as necessary executables, libraries, binary code, and configuration files.

They are a streamlined way to create, test, deploy, and redeploy applications in multiple environments.

Benefits of Containers are listed below:

  • Less overhead
  • Improved productivity
  • More consistent operation
  • Better application deployment
  • Greater efficiency

Q50. What is a Docker Container and how do you create it?

Ans.

  • A Docker container is an open-source software development platform which stores the code and all of its dependencies and runs the application quickly and reliably from one computing environment to the other.
  • Docker containers are not specified to any particular infrastructure; they can run on any infrastructure, on any computer, and in any cloud.
  • A Docker container image is a standalone, lightweight, and executable package of software that has everything to run the application such as code, system tools, runtime, system libraries, and settings.

Docker Containers can be created with the Docker image using the following command:

docker run -t -i <image name> <command name>

This will create and start the container.

If you want to check the list of all running containers with status on the host, use the following command:

docker ps -a

If you have any additional DevOps questions and unable to find the answers, please do mention them in the comment section below. We’ll get back to you at the earliest.

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