Interview Questions and DevOps

Top DevOps Interview Questions and Answers

Posted in Interview Questions, DevOps
 Top DevOps Interview Questions and Answers

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DevOps stands for Development and Operations. It is a new form of software development that has revolutionized the way software products are developed and distributed. The DevOps methodology focuses on providing frequent smaller upgrades rather than rare big feature sets.

IT operations benefit from DevOps. Before the advent of DevOps, several concerns remained intrinsic to the IT team. This resulted in the IT team facing some level of undesired suspicion.

However, that all changed with the entry of DevOps, which allows the IT operations to share these concerns with the rest of the organization resulting in enhanced transparency and better coordination between the IT operations and the other teams.

Top DevOps Interview Questions and Answers

The following section features the top DevOps Interview Questions and Answers that will prepare you for your next DevOps interview:

Question: What are the different phases in DevOps?

Answer: DevOps is mainly classified into 6 phases. Its phases are in a particular cycle. However, all the phases are not separated by boundaries, and no phase begins even if the previous one has ended completely. Now, let's study the DevOps cycle phase in more detail.

1. Planning

Planning and software development is the first phase of the DevOps lifecycle. This phase involves understanding the project properly for the ultimate work goal of its participants. This also feeds the various phases of development and operations. It's also important that organizations are trained on tools and metrics to have enough clarity of the project's management.

2. Development

In this phase, the project gets built by designing infrastructure, writing codes, defining tests, or by automation process. Evidence is important in this phase. In managing applications, operations with data, developers store codes in code manager, which allows viewing, versioning, and much more.

3. Continuous Integration

This phase automates the mechanism of validation, testing. This has a unique feature that ensures the development environment is properly and then published in a service that integrates it with the remaining applications.

4. Automated Deployment

DevOps stimulates the automation of deployments by tools and scripts with the ultimate goal of solving the whole process with the activation of a feature. The most important aspect of this phase is the arrival of the cloud, as a code that forces a change from finite infrastructure management to permanent cost optimization management.

5. Operations

Usually, all operations related to DevOps happen continuously throughout the life of software, as there is a dynamic change in the infrastructure. This platform provides opportunities for transformation, availability, and scalability.

6. Monitoring

This phase is a permanent phase of the DevOps process. DevOps monitors and analyzes information that displays the current status of the application.

Question: Why has DevOps gained popularity over the past few years?

Answer: Nowadays, DevOps are in great demand in the current industry, and many businesses are eagerly wanting to invest in DevOps talent. Some of the huge multi-national companies such as Facebook and Netflix are investing their money and time in DevOps for automation and pacing up application deployment as every large industry wants to see some automation in the coming years. It helps the organizations to grow and expand their businesses to generate large revenues. Its popularity continues to grow in demand as tech competition increases as most companies start adopting DevOps practices; then, it becomes even more important for the competitors to invest in similar or better development practices, increasing demand.

DevOps implementation has given provable results in businesses which contend higher efficiency, with its new technology standards; tech workers can implement codes faster than ever before, and with lesser errors. As now, more consumers and businesses rely on cloud software as it requires fast deployments to meet the consumer needs without interrupting services; this increases user adoption of cloud software like DevOps over the years.

Question: What is the difference between Ansible and Puppet?

Answer: Today, DevOps professionals have to manage and control a huge number of servers hosting, so for this, they need exponential growth in computing as well as new technology such as virtualization and cloud computing. Thus Puppet and Ansible are the tools that are used for managing a large number of servers.

These are also called Remote Execution and Configuration Management tools, and it allows the admin to perform or execute the commands on many servers simultaneously. Its main feature is generally to maintain and configure thousands of servers at a single time. Apart from this, Ansible and Puppet has major differences right from the moment and can be differentiated concerning many mechanisms as shown below:

Category

  1. Ansible
  2. Puppet

Scalability

  1. Scalability in Ansible is very convenient and simple.
  2. Puppet also offers scalability but somewhere lacks as compared to ansible

Management and Scheduling

  1. In ansible, configuration gets pushed to the nodes from the server for better employment of code.
  2. In puppet, configuration gets pulled from the selected server.

Language

  1. It is fully published in Python and uses YAML syntax to convey or write configurations.
  2. It is written in Ruby and uses declarative language to form the configurations.

Availability in case of failures

  1. In this case, availability will have lesser worries as the subordinate node is present in case of any nodal failure.
  2. In this case, many multiple master servers are present so that if the original master fails, it does not stop the ongoing task.

Repository

  1. The repository of Ansible is Ansible Galaxy, where all the information is stored.
  2. A storehouse of the puppet is Puppet forge, which has 6000 modules.

Setting up and Usage

  1. Ansible has a master that runs the client machine and writes the configuration to manage tasks.
  2. Puppet uses a client-server architecture to manage complex tasks.

Question: What are the benefits of using the Version Control System (VCS)?

Answer: The key benefits of Version Control are as follows:

  1. With the Version Control System (VCS), all the workers are allowed to access the file freely at any time. It also allows merging all the changes that are made in a common version.
  2. It is designed to help multiple people by collaboratively edit text files, which makes sharing comparatively easy between multiple computers.
  3. It is important for documents that require a lot of redrafting and revision as they provide an audit trail for redrafting and updating final versions.
  4. It permits all the team members to have access to the complete history of the project so that in case of any breakdown in the central server, we can use any teammate's storehouse.
  5. All the previous versions and variants are smartly packed up inside the VCS. Any version is requested at any time to get information about the previous complete projects.

Question: What are the different components of Selenium?

Answer: Selenium is an open-source tool that is used for automating different web applications. It has mainly four major components that help to run multiple test cases and provides services of using various browsers and languages for automation. The components of Selenium are as follows:

1. Selenium IDE

Selenium IDE (Integrated Development Environment) is one of the simplest frameworks in the selenium suite. It has an easy record and playback function, which helps in figuring the tool that provides easy learning. If the tester is aware of the basics of HTML, JavaScript, and DOM, it is easier to utilize Selenium IDE. It enters the commands quickly and reduces the possibility of entering invalid commands.

2. Selenium RC

Selenium RC (Remote Control) is a tool that helps in understanding test scripts and providing support for different programming languages like Ruby, PHP, Java, etc. It mainly depends upon JavaScript for automation and does not support record and playback features.

3. Selenium WebDriver

It is mainly the extension of selenium RC, but it supports all the latest browsers and various platforms. It is created to support vital web pages in which elements present on the page can change without reloading the page, and it directly calls the browser for automation.

4. Selenium GRID

Selenium GRID is a tool that runs multiple test cases against different browsers and machines in parallel. Several nodes are not fixed in the grid, and it can be launched on various browsers and platforms. It is used together with selenium RC.

Question: What is the purpose of configuration management in DevOps?

Answer: Configuration management helps in automating tasks that are otherwise time-consuming and tedious and enhances an organization's agility. It brings consistency and improves the process of a product/service by streamlining design, documentation, control, and implementation of changes during various phases of the project.

Question: What is the purpose of AWS in DevOps?

Answer: AWS services support the automation of manual tasks and processes that help developers build applications faster and more efficiently. These processes can be deployment, development, test workflows, configuration management and container management.

Question: What is the difference between a centralized and distributed version control system (VCS)?

Answer: In a centralized repository system, the repository is located in a central location, and clients access this system when they need something. In such a version control system, the repository is always updated with the latest changes as the changes are directly committed to the central system; therefore, all the clients always have access to the latest code. CVS and SVN are examples of centralized VCS.

In a distributed VCS, everyone in the team has their repository, which is a mirror of the central repository. It provides flexibility, as one can work offline. Only when the changes have to be committed to the central system, you need to be online. This makes distributed VCS faster. Git and Mercurial are distributed VCS.

Question: Explain the differences between git pull and Git fetch?

Answer:

git fetch git pull
the command to use this feature is: git fetch <remote> command to use: git pull <remote> <branch>
Fetches the changes from the remote repository but doesn't merge them with the local repository. Fetches the changes of the branch from the remote repository and merges them with the local repository. pull = fetch + merge
Done at latter stages, since no merging is involved, there are no conflicts to be resolved. There are chances of merge conflicts if two or more people are working on different copies of the same code/file.
The local repository is unchanged, but the central repository is updated. The changes from the central repository are updated in the local repository.
Developers can see the changes made by others before they push their changes for integration. Developers can first bring the latest files to their local, and then start updating the same.

Question: What is git stash?

Answer: Git stash command is used to save the changes temporarily in the working directory. This gives developers a clean directory to work on. They can later merge the changes in the git workflow. If this command is used, the changes in the tracked files are merged in the working directory. Git stash command can be used many times in the git directory. It is used as git stash

Question: What is a merge conflict in Git, and how can it be resolved?

Answer: Merge conflicts occur when changes are made to a single file by multiple people at the same time. Due to this, Git won't be able to tell which of the multiple versions is the correct version. To resolve the conflicts, we should create a new Git repo, add a file, create a branch, make the edits and commit the changes. The next step is to merge the new branch into the master. Once this is done, Git clearly shows the differences in the different versions of the file and where the edits need to be made to remove the conflicts.

Question: Can you tell us the fundamental differences between DevOps & Agile?

Answer: Although DevOps shares some similarities with the Agile methodology, which is one of the most popular SDLC methodologies, both are fundamentally different approaches to software development. Following are the various fundamental differences between the two:

  • Agile Approach – The agile approach is only meant for development in Agile while the agile approach is meant for both development and operations in DevOps.
  • Practices and Processes – While agile involves practices such as Agile Scrum and Agile Kanban, DevOps involves processes such as CD (Continuous Delivery), CI (Continuous Integration), and CT (Continuous Testing).
  • Priority – Agile prioritizes timeliness whereas, DevOps gives equal priority to timeliness and quality.
  • Release Cycles – DevOps offers smaller release cycles with immediate feedback while Agile offers only smaller release cycles without immediate feedback.
  • Feedback Source – Agile relies on feedback from customers while feedback from self (monitoring tools) is involved in DevOps.
  • Scope of Work – For Agile, the scope of work is agility only but for DevOps, it is agility and the need for automation.

Question: Why do we need DevOps?

Answer: Organizations these days are trying to transport small features to customers via a series of release trains instead of releasing big feature sets. There are several benefits of doing so, including better software quality and quick customer feedback.

All such benefits lead to a higher level of customer satisfaction, which is the most important goal for any product development project. To do so, companies need to:

  • Increase deployment frequency
  • Lessen lead time between fixes
  • The lower failure rate of new releases
  • In case of new release crashing, have a faster mean time to recovery

DevOps helps in fulfilling all these requirements and thus, achieving seamless software delivery. Full-fledged organizations like Amazon, Etsy, and Google have adopted DevOps methodology resulting in achieving performance levels that were previously uncharted.

With the adoption of DevOps methodology, organizations are able to accomplish tens to thousands of deployments in a single day. Moreover, doing so while offering first-rate reliability, security, and stability.

Question: What are the important business and technical benefits of using DevOps?

Answer: DevOps brings a lot of business and technical benefits to the table. Some of the most important ones are listed down as follows:

Business benefits

  • Enhanced operating environment stability
  • Faster delivery of features
  • More time for adding value to the product

Technical benefits

  • Continuous software delivery
  • Faster problem resolution
  • Lesser complex problems

Question: Can you name some of the most-used DevOps tools?

Answer: Following is a list of some of the most widely used DevOps tools:

  • Ansible – A configuration management and application deployment tool
  • Chef – A configuration management and application deployment tool
  • Docker – A containerization tool
  • Git – A version control system (VCS) tool
  • Jenkins – A continuous integration (CI) tool
  • Jira – An agile team collaboration tool
  • Nagios – A continuous monitoring tool
  • Puppet – A configuration management and application deployment tool
  • Selenium – A continuous testing (CT) tool

Question: What is Selenium used for?

Answer: Selenium is used for continuous testing in DevOps. The tool specializes in functional and regression forms of testing.

Question: What do you understand by Puppet in DevOps?

Answer: It is a configuration management tool that is used for automating administration tasks. Puppet makes use of the Master-Slave architecture in which the two entities communicate via an encrypted channel.

System admins need to perform a lot of repetitive tasks, notably installing and configuring servers. Writing scripts for automating such tasks is an option but it becomes hectic when the infrastructure is large. Configuration management is a great workaround for this.

Puppet helps in configuring, deploying, and managing servers. Not only does it make such redundant tasks easier but it also cuts a significant portion of the total work time. The mature configuration management tool:

  • Continuously checks whether the needed configuration for a host is in place or not. If altered, the configuration is automatically reverted back
  • Defines distinct configurations for every host
  • Does dynamic scaling (up and down) of machines
  • Provides control over all the configured machines so that a centralized change can automatically get propagated to all of them

Question: What do you understand by anti-patterns of DevOps?

Answer: When a DevOps pattern commonly adopted by other organizations doesn’t work in a specific context and still the organization continues using it, it leads to the adoption of an anti-pattern. In other words, anti-patterns are myths about DevOps. Some of the notable anti-patterns are:

  • An organization needs to have a separate DevOps group
  • Agile equals DevOps
  • DevOps is a process
  • DevOps is development-driven release management
  • DevOps is not possible because the organization is unique
  • DevOps is not possible because the people available are unsuitable
  • DevOps means Developers Managing Production
  • DevOps will solve all problems
  • Failing to include all aspects of the organization in an ongoing DevOps transition
  • Not defining KPIs at the start of a DevOps transition
  • Reduce the silo-based isolation of development and operations with a new DevOps team that silos itself from other parts of the organization

Question: DevOps has something called CI. What is it and what is its purpose?

Answer: CI in DevOps stands for Continuous Integration. CI is a development practice in which developers integrate code into a shared repository multiple times in a single day.

Continuous Integration of development and testing enhances the quality of the software as well as reducing the total time required for delivery.

The developer has broken the build if a team member checking in code runs into a compilation failure. As such, other developers are not able to sync with the shared source code repository without introducing compilation errors into their own workspaces.

This disrupts the collaborative and shared development process. Hence, as soon as a CI build breaks, it’s important to identify and correct the problem immediately.

Typically, a CI process includes a suite of unit, integration, and regression tests that run each time the compilation succeeds. In case any of the aforesaid tests fail, the CI build is considered unstable (which is common during an Agile sprint when development is ongoing) and not broken.

Question: More often than not we hear shift left in DevOps. What is it?

Answer: The traditional software development lifecycle when graphed on a paper has two sides, left and right. While the left side of the graph includes design and development, the right side includes production staging, stress testing, and user acceptance.

To shift left in DevOps simply means the necessity of taking as many tasks on the right i.e. that typically happens toward the end of the application development process and incorporates them into earlier stages of a DevOps methodology.

There are several ways of accomplishing a shit left in DevOps, most notably:

  • Create production-ready artifacts at the end of every Agile sprint
  • Incorporating static code analysis routines in every build

The level of doing the DevOps the right way is directly dependent on the degree of shifting left as much as possible.

Question: What does CAMS in DevOps stand for?

Answer: The acronym CAMS is usually used for describing the core creeds of DevOps methodology. It stands for:

  • Culture
  • Automation
  • Measurement
  • Sharing

Question: What are the several KPIs used to gauge DevOps success?

Answer: KPIs is a contracted form of Key Performance Indicators. In order to measure the success of a DevOps process, several KPIs can be used. Some of the most popular ones are:

  • Application performance
  • Application usage and traffic
  • The automated test pass percentage
  • Availability
  • Change volume
  • Customer tickets
  • Defect escape rate
  • Deployment frequency
  • Deployment time
  • Error rates
  • Failed deployments
  • Lead time
  • Mean time to detection (MTTD)
  • Meantime to recovery (MTTR)

Question: In your opinion, what are the major benefits of implementing DevOps automation?

Answer: Following are the major benefits of implementing DevOps automation:

  • Removal of the possibility of human error from the CD equation (Core benefit).
  • As tasks become more predictable and repeatable, it is easy to identify and correct when something goes wrong. Hence, it results in producing more reliable and robust systems.
  • Removes bottlenecks from the CI pipeline. It results in increased deployment frequency and decreased number of failed deployments. Both of them are important DevOps KPIs.

Question: What do you understand by containers?

Answer: Containers are a form of lightweight virtualization that help in providing isolation among processes. Containers are heavier than a chroot but lighter than a hypervisor.

Answer: There are several Java frameworks that allow creating microservices. However, Eclipse MicroProfile and Spring Boot stand out from the herd as the two leading Java development frameworks used in DevOps for creating microservices.

Question: What do you understand by a Version Control System (VCS)? Define its uses.

Answer: A Version Control System or VCS is a system that is capable of recording changes made to a file or a group of files over time. Git and Mercurial are two of the most popular version control systems. Important uses of a VCS are:

  • Check what was the last modification that caused a problem
  • Compare the changes made over time
  • Identifying who introduced a new issue and at what time
  • Revert a file or files to some earlier state
  • Revert the complete project to a previous state

Answer: There are two ways of doing so:

  • By creating a new commit to undo all changes made by the commit that has already been pushed and made public. Following command is used for doing so:
    git revert
  • By fixing or removing the bad file in a new commit and then pushing it to the remote repository. After making necessary changes to the file, commit it to the remote repository using the command:
    git commit -m “commit message”

Question: What are post mortem meetings?

Answer: Many times there is a need to discuss what went wrong during a DevOps process. For this, post mortem meetings are arranged. These meetings yield steps that should be taken to avoid the same failure or set of failures in the future for which the meeting was arranged in the first place.

Question: Draw a comparison between Asset Management and Configuration Management.

Answer: The process of monitoring as well as maintaining things of value to an entity or group is called an Asset Management.

Configuration Management refers to the process of controlling, identifying, planning for, and verifying the configuration items within service in support of Change Management.

Question: Can you state and explain various key elements of continuous testing?

Answer: Various key elements of continuous testing are:

  • Advanced analysis – Used for forecasting and predicting unknown future events
  • Policy analysis – Meant for improving the testing process
  • Requirement traceability – Refers to the ability to describe as well as follow the life of a requirement, from its origin to deployment
  • Risk assessment – The method or process of identifying hazards and risk factors that can cause potential damage
  • Service virtualization – Allows using virtual services instead of production services. Emulates software components for simple testing
  • Test optimization – Improve the overall testing process

Question: Please explain the core operations of DevOps in terms of development and infrastructure.

Answer: Core operations of DevOps in terms of development and infrastructure are:

  • Application development – Developing a product that is able to meet all customer requirements and offers a remarkable level of quality
  • Code coverage – a measurement of the total number of blocks or lines or arcs of the code executed while the automated tests are running
  • Code developing – Prepare the codebase required for the product development
  • Configuration – Allowing the product to be used in an optimum way
  • Deployment – Installing the software to be used by the end-user
  • Orchestration – Arrangement of several automated tasks
  • Packaging – Activities involved when the release is ready for deployment
  • Provisioning – Ensuring that the infrastructure changes arrive just-in-time with the code that requires it
  • Unit testing – Meant for testing individual units or components

Question: What is DevOps?

Answer: DevOps is the value-added practice wherein the development, as well as operation engineers, work together from the initial point of designing a product to deployment in the markets.

Question: What is the basic premise of DevOps?

Answer: DevOps is a cultural shift wherein a collaboration and operation teams work together throughout the product or service life cycle.

Answer: DevOps is related to Agile methodology.

Question: What are the priorities in DevOps?

Answer: The priorities in DevOps include resource management, teamwork, and communication.

Question: What are the benefits of DevOps?

Answer: The varied benefits of DevOps include innovation, stability, functionality, and speed.

Question: What are the different advantages of Git?

Answer: Git has the following advantages:

  1. It helps in data redundancy and replication.
  2. It is highly available.
  3. It supports collaboration.
  4. It can be used for a variety of projects.
  5. It uses only one Git directory per repository.
  6. It supports disk utilization.
  7. It offers higher network performance.

Question: What is the difference between Git fetch and Git pull?

Answer: Git pull is common that pulls any new commits from a branch of the central repository to update the target branch. Git fetch pulls any new commits from only the desired branch and then stores them into a new brand of the local repository.

Question: Can we handle merge conflict in Git?

Answer: Yes, we can handle merge conflict in the following three steps:

  • Step 1: Developing a clear understanding by checking everything using Git status.
  • Step 2: Mark and clean up the conflict by applying the merge tool.
  • Step 3: Performing commit and merging with the current branch along with the master branch.

Question: What is Forking Workflow?

Answer: Forking Workflow gives every developer with their service side repositories, thereby supporting open source projects.

Question:How is Forking Workflow better than Git Workflow?

Answer: Forking Workflow is better than Git Workflow because it helps in integrating the contributions of different developers without needing everyone to push to a single central repository for cleaning project history. Thus the developers are allowed to push their server-side repositories, and thereby on the project maintainer will push to the official repository.

Question: What is Git rebase?

Answer: Git rebase is a command which is designed to integrate the changes from one branch to another brand.

Question: How is Git rebase different from Git merge?

Answer: Git rebase is different from Git merge because, in the case of Git rebase, the feature branch is transferred to the master branch's ending point. However, in the case of Git merge, the merging adds to a new commit in the history wherein history does not change, but the master branch is changed.

Question: Can we move or copy Jenkins from one server to another?

Answer: Yes, we can move or copy the Jenkins from one server to other. For instance, by copying the Jenkins jobs directory can be moved from the older server to the new server. This way, installation can be moved from one installation to another by copying in the corresponding job directory.

Question: Can we make a new copy of an existing Jenkins job?

Answer: Yes, we can make a new copy of an existing Jenkins job by creating a clone of the directory in a different name.

Question: What is the difference between continuous testing and automation testing?

Answer: In continuous testing, the process of executing the automated test is part of the software delivery process. 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.

Question: What is the role of a Selenium Grid?

Answer: The role of a Selenium Grid is to execute the same or different test scripts and that too on different platforms and browsers so that the distributed test execution can be made. It helps in testing under various environments and offers an ability to save execution time.

Question:Can we secure Jenkins?

Answer: Yes, we can secure Jenkins in the following ways:

  1. Ensuring that global security is on
  2. Checking if Jenkins is integrated
  3. Making sure that the project matrix is enabled
  4. Automating the process of setting up rights and privileges
  5. Limiting physical access to Jenkins data
  6. Applying security audits regularly

Question:What is Jenkins Pipeline?

Answer: Jenkins pipeline is a suite of plugins that supports the implementation and integration of Jenkins's continuous delivery pipeline.

Question:What is continuous integration?

Answer: Continuous integration, also known as a continuous delivery pipeline, includes functions of build, deploy, test, and release. It is a time-saving feature and builds jobs that are integrated and chain into a particular sequence.

Question: What is a Puppet Module?

Answer: Puppet Module is a collection of manifest and data, including files, templates, and facts that have a specific directory structure.

Question: How is the Puppet Module different from Puppet Manifest?

Answer: Puppet Manifests use the .pp extension. They are Puppet programs, which consist of the Puppet Code. On the other hand, Puppet Modules organizes various kinds of Puppet Manifests that can split the Puppet code with it.

Question: What is Ansible work in DevOps?

Answer: Ansible work is an open-source automation tool used in DevOps.

Question: What are the categories of Ansible in DevOps?

Answer: There are two categories of Ansible in DevOps which include,

  1. Controlling machines.
  2. Nodes.

Question: Can we install Ansible on the controlling machines?

Answer: Yes, we can install Ansible on the controlling machine by using the machine nodes that are managed with the help of SSH.

Question: Are Ansible agentless tool? What are its benefits?

Answer: Yes, Ansible is an agentless tool because it does not require any kind of mandatory installations on the remote nodes. The benefits of the Ansible tool include the following:

  1. Task automation
  2. Configuration management
  3. Application deployment

Conclusion

That completes the list of the Top DevOps interview questions and answers. In addition to increasing your chances of securing a DevOps job, these will definitely help you assess as well as enhance your current level of DevOps understanding.

Looking for more DevOps interview preparation content? DevOps Interview Questions Preparation Course will take you one step closer to your next DevOps job.

DevOps interview will not have questions only about DevOps; the interviewer will certainly ask you some generic software development questions as well. Cracking the Coding Interview: 189 Programming Questions and Solutions can help you prepare for generic programming interview questions.

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Vijay Singh

Vijay Singh

My name is Vijay Singh Khatri, and I enjoy meeting new people and finding ways to help them have an uplifting experience. I have had a variety of customer service opportunities, through which I was able to have fewer returned products and increased repeat customers, when compared with co-workers. Currently working with hackr.io View all posts by the Author

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