Top DevOps Interview Questions

DevOps is an acronym that contains the abbreviations of two inextricable parts of any business process i.e Development and Operations.DevOps help in the creation of resilient and competent software suites and tools that help in the development and deployment of high-quality Software-as-a-Service (SaaS) products in a fast-paced, efficient manner.

DevOps requires knowledge of software deployment practices, concepts like Software Development Life Cycle (SDLC), LINUX fundamentals and others like Infrastructure Management capabilities that are achieved using specialized DevOps deployment tools like Docker, Kubernetes, Ansible etc. These qualities are tested at first during the DevOps analyst interview where the employers look for particular traits within you, the candidate.

But don’t worry, today we are going to look at the Top 50 DevOps interview questions in great detail so that you feel at ease while giving that interview.

Q.What is Agile Methodology?

A: Agile Methodology is the base concept of the software development life cycle and is the method where there are continuous iterations in the development and testing phases. These phases are operated and managed concurrently.

Q. What is DevOps and why is it considered an upgrade on Agile Methodology?

A: DevOps is considered an upgrade on Agile methodology as Agile focuses purely on the software development life cycle and its operations. It is concerned mainly with the efficient development of the software whereas DevOps is a work culture that is focused on development as well as the fast-paced and seamless deployment and delivery of top-quality software.

Q.Why do we need DevOps?

A: DevOps is an enhanced principle that helps in seamless development and integration of top-notch software in a series of releases instead of a massive outage. It results in the following benefit owing to which DevOps is desired:-

• Faster integration of software
• Enhanced operating capability
• Reduced time to focus on bug fixes and improvements
• Continuous development and deployment life cycle
• Addresses gaps between Developers and IT operations and brings them on a singular platform.

Q.What are the various phases of a DevOps process?

A: The important phases of a DevOps process include:-

• Planning
• Code Development
• Building/Congregating the code
• Testing
• Integration
• Deployment
• Monitoring
• Feedback

Q.What are the various DevOps tools used?

A: The various DevOps tools used in operations are:-

• Git
• Jenkins
• Docker
• Kubernetes
• Ansible
• Metabase
• Chef
• Puppet, and
• Selenium

All these tools perform different tasks which are ultimately intended for the proper deployment of iterated and foolproof software.

Q.What are the purposes of the various DevOps tools?

A: The various DevOps tools mentioned in the previous question have intended tasks which are the following:-

• The code is first created and stored in Git which is a ‘code repository’ or a storehouse for the code and the intended information veiled in it
• Any changes to be made in the code before version development and deployment is done within the Git environment. Git is also called a ‘Version Control System.’
• A process integration tool called Jenkins then avails the code from the Git repository and develops the program around it using building tools like Ant or Maven.
• Once developed Jenkins then provisions testing environment which is managed by a tool called ‘Selenium.’
• Puppet is used for deployment over production (Puppet provides production servers for the same)
• After production, the software can be monitored using a tool called Nagios.
• Docker provides the required testing environment to test the build features

Q.Enlist the various DevOps KPIs?

A: The three main DevOps KPIs are:-

• Mean time to recover from failure or error
• Deployment frequency
• Failed deployment rate
• Availability
• Change volume
• Lead time to deployment
• Application performance (main)
• Error frequency

Q.What are anti-patterns in DevOps?

A: Anti-patterns are considered as common myths within the DevOps usage and are opposite to what is the common custom for employing DevOps practices. Some of the common anti-patterns of myths in DevOps are:-

• DevOps is a process
• Agile equals DevOps
• Every organization needs to have a separate DevOps group
• DevOps will solve all problems
• DevOps is development driven-release management
• Not defining KPIs at the start of a DevOps session
• We can’t do DevOps because we got the wrong people or either because we are unique

Q.Determine the role of AWS in DevOps.

A: AWS stands for Amazon Web Services who are considered the pioneers in the DevOps industry. AWS helps in managing DevOps processes by performing the following role(s):-

• Flexible services:- Provides ready-to-use services without the need to install or set up the software
• Built for scale:- You can manage a single instance or manage thousands of them using AWS services.
• Automation:- AWS lets you automate tasks and processes, giving you more time to innovate
• Secure Usage:- Using AWS Identity and Access Management (IAM), you can set user permissions and policies.
• Large partner ecosystem:- AWS supports a large ecosystem of partners that integrate with and extend AWS services.

Q.What is Version Control in DevOps?

A: As the name suggests, Version Control is a part of Git operations. In Version Control, iterative developments and changes to the code or structure are recorded and kept note of which can be recalled as a safety measure when any error occurs in the program. Consider it like how video games are saved.Once recorded, Version Control contains a centrally shared repository where teammates and authorized personnel can commit changes to the code or the file.

Version control helps to:-

• Revert changes to the last committed version
• Revert file changes to the last committed version
• Compare and contrast developments
• See who last modified something within the repository
• Where the issue occurred?

Q.Differentiate between Centralized and Distributed Version Control System

Q.Enlist the advantages of using Git

A: The various advantages of using Git are:-

• Retractable to previous committed versions
• Easy availability for anyone
• Collaborative
• Superior disk utilization and performance
• Easy data replication due to single Git directory/repository

Q.Explain the way to find a list of files that have been changed in a particular commit

A: This can be done using the command

git diff-tree –r {commit hash}

• The -r flag provides the command to list all individual files
• Commit hash will list all the files that were changed in the commit

Q.Differentiate between Git fetch and Git pull

Q. Explain Continuous Integration?

A: Continuous Integration is defined as the process that compiles all the code in the user database and facilitates the flow from code availability to development to deployment for production. Example of a CI tool in DevOps is Jenkins tool.

A limitation though with CI can be that since it is the fulcrum of the DevOps process, any small bug within the process or the code which someone enters within the repository when pulled can cause the build to break down and has to be rectified immediately otherwise the process has to be restarted again.

Q.List the factors that lead to successful Continuous Integration

A: The various factors that lead to a successful integration of the code to production through Continuous Integration are:

• Maintain a code repository
• Build the code
• Create self-testing environments
• Make everyone commit to the code base
• Record the code commitments
• Hasten the build
• Test in a rehearsal version of production environment
• Keep results viewable to everyone in the development lifecycle
• Facilitate deployment and manage any errors and keep to minimum

Q.Describe the key aspects of Jenkins

A: Some of the key aspects of the Jenkins pipeline are:-

• Pipeline:- The pipeline’s code defines the entire build process right from building, testing to deploying an application
• Node:- A machine that is capable of running a pipeline within the Jenkins environment
• Stage:- Defines a conceptual list of tasks that are to be performed in the pipeline
• Step:- A particular notion that defines what must happen in a pipeline at a particular time

Q.Mention some of the most useful plugins in Jenkins

A: Some of the most useful plugins for Jenkins include:-

• Maven 2 Project
• Green Balls
• Join
• Copy Artifact
• Azure Container Service
• Amazon ECS Container Service

Q.What are the commands used to restart Jenkins manually?

A: There are two basic commands that are used to restart Jenkins, these are:-

• (Jenkins_url)/restart:- Forces restart without waiting for builds to complete
• (Jenkins_url)/Saferestart:- Waits for all builds to complete before restarting

Q. Name the security mechanisms Jenkins uses for user authorization

A: Jenkins uses three major security mechanisms for user authorization:-

• Internal database to store user records
• Lightweight User Directory Access Protocol (LDAP) servers to authenticate
• Jenkins can be configured to employ the authentication mechanism that the deployed application requires.

Q. Differentiate between continuous delivery and deployment?

Q.What is configuration management in DevOps?

A: Configuration management is a technique employed to handle the various resources and systems within the environment and their changes to maintain uniformity in the infrastructure.

• Enables changes to multiple systems
• Manages overall uniformity and integrity of the IT infrastructure
• Administers and manages multiple IT systems within the infrastructure environment.

Q. Explain the difference between Asset Management and Configuration Management

A: Asset Management:-

• Concerned with operation finances
• Scope is everything you own
• Interfaces to purchasing and leasing
• Maintains data for taxes
• Only incidental relationships

Configuration Management:-

• Concerned with operations
• Scope is everything you deploy
• Interfaces to ITIL operations
• Maintains data for troubleshooting
• Maintains operational relationships

Q.Elucidate the meaning of “Infrastructure as Code (IaC)” in configuration management?

A: IaC combines the concept of two very key features of DevOps process i.e Infrastructure and code. When there is a machine-readable code file that helps order and manage the system infrastructure environment’s configuration and deployment as well as other cloud units that form part of the scene as virtual servers within the setup is called “Infrastructure as Code”.

Q.Explain the key elements of Continuous Testing

A: The key elements of Continuous Testing are:-

• Advanced analysis:- For ascertaining key measures and predict future growth
• Requirements tracing:- Describing and working towards achieving the particular requirement which is obtained as a result of the testing
• Risk assessment:- Identifying potential risks and working on keeping them to a bare minimum by improving system working factors like efficiency and safe-guarding.
• Testing optimization:- Improving the overall testing procedure’s efficiency to find even minute shortcomings and errors

Q.Differentiate between Continuous and Automation testing

A: Continuous Testing is the process of executing the automated test is part of the software delivery process in DevOps. Each build is tested continuously allowing the build team to receive constant feedback to prevent increase in errors.

In contrast, Automation Testing is a process wherein the manual process of testing is applied wherein the separate testing tool helps the developers in creating test scripts that can be executed again and again without any kind of manual intervention.

Q.List the benefits of Automation Testing

A: There are many benefits of Automation Testing, some of which are:-

• Supports execution of repeated test cases
• Helps in testing a large test matrix
• Enables parallel execution
• Improves accuracy
• Saves time and money

Q.Define how to launch a browser using WebDriver?

A: To launch a browser using WebDriver requires different responses across multiple platforms:

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

Q.Explain Forking Workflow? How is it better than Git Workflow?

A: Forking Workflow provides extra options for the developer like side source repositories for performing open-source projects.

Forking Workflow is considered better than Git because it helps integrate the contributions of all developers without needing everyone to push their commit to the central repository. They can rather push in their server-side repositories which ensures the central project maintainer is pushed to and remains in the central repository.

Q.Define Selenium

A: Selenium is a dedicated IDE that facilitates the Selenium environment for recording and debugging tests of DevOps processes. It is implemented as a Firefox extension. It contains the Selenium Core that will help you record and run tests in the actual production environment. Selenium supports two types of testing:-

• Regression Testing:- The testing around an area where a bug was fixed
• Functional Testing:- Testing individual software features

Using Selenium has a host of advantages such as:

• Free, open-source
• Browser compatible (Firefox, Chrome, Safari etc)
• Platform compatible (Linux, Windows, MAC)
• Allows distributed testing (in parts)
• Regular repository developments

Q.What are the various Selenium components?

A: The different Selenium components are:-

• Selenium IDE
• Selenium Remote Control (SRC)
• Selenium Core
• Selenium WebDriver
• Selenium Grid

Q.What are Puppet Manifests?

A: Puppet Manifests are documents that contain code written in native Puppet language that is understandable for the Puppet Master to decipher and create instances of within slave files that are connected to the Puppet master.

Every Puppet Agent or Node consists of these manifests and they are saved using the .pp extension.

Q.What is Ansible and how does it work?

A: Ansible is an open-source automation tool and is categorized into two types of servers, controlling machines and nodes. It is installed on the controlling machine and using that machine nodes are managed with the help of SSH. Node locations are mentioned by inventories within that controlling machine.

Q.What is Kubernetes?

A: Kubernetes is one of the most prominent tools used for open-source automation of application deployment, scaling and management. It is considered a container orchestration system that provides specialized environments for such purposes and works together with other environment tools like Docker.

Q.List the usual Kubernetes objects

A: Some of the prominent Kubernetes objects are:-

• Pods
• Replica Sets
• Namespaces
• Daemon Sets
• Stateful Sets
• Services, and
• Volumes

So those were some of the prominent interview questions asked for DevOps. I hope you found this blog informative. If you want to know more about DevOps and want to specialise in it. Just a few clicks and you will be done.

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