25 DevOps Interview Questions You Need To Know The Answers To
How do you understand the philosophy of DevOps?
DevOps is an approach in which software engineers and administrative engineers participate in the entire software product lifecycle, from design and development to comprehensive product support. DevOps is designed to eliminate the traditional siloing where one team writes code, another team tests it, the third deploys it, and the fourth is responsible for operations. Instead, the primary methods include agile management and prioritization of people, processes, and tools.
When do you need DevOps?
DevOps is needed when a company wants to create and improve products faster than conventional software development approaches. It is a software development methodology whose task is to establish cooperation between programmers and sysadmins in the company.
What are the critical components of DevOps?
The main components of DevOps practices are development, Integration, testing, deployment, monitoring, feedback, and operations.
What are DevOps best practices?
DevOps practices are logical actions that improve the quality of the products created. It is achieved by prioritizing customer satisfaction, proactive participation of all stakeholders, leveraging Agile methodologies, implementing continuous Integration and delivery, implementing test automation, and monitoring metrics.
What are the most frequently used DevOps tools?
DevOps tools are very numerous, and they are all divided by their functionality:
- Source code management,
- Cloud tools,
- Continuous Integration,
- DevOps Clusters,
- Command Line Networks,
- Network Protocols.
No DevOps development can do without Git and GitHub, Jenkins, Ansible, Docker, or their analogs.
Are Agile and DevOps the same?
Not really. Agile involves different people responsible for software development, testing, and deployment. In DevOps, the person performing the role of DevOps engineer is responsible for everything. DevOps is more associated with cost reduction, while Agile is related to lean development and reducing unnecessary spending.
Describe “Canary Release”
The new functionality or its updated part is published to a limited audience when it is ready for the production environment. Therefore, before deploying, it is sufficient to ensure that the code does not contain syntax errors.
After testing the functionality, which is already in the environment where real users will start interacting with it, you can open access to real users wholly or partially. Then, if errors are found, the feature can be instantly shut down from users and minimize losses (reputational and financial).
How do you understand Infrastructure as a Code?
Infrastructure as Code (IaC) pioneered the elimination of boundaries between writing applications and creating environments for those applications. Applications can contain scripts that create and manage virtual machines. It removes the need for manual configuration and updates for individual hardware components. This is the foundation of cloud computing and an integral part of DevOps.
What is Configuration Management in DevOps?
Automation and management of system configuration are one of the main concepts of DevOps. Configuration management means recording information about specific infrastructure settings so you can understand when changes have been made.
What is the difference between continuous deployment and continuous delivery?
These terms refer to the concept of Continuous Delivery, but with Continuous Deployment, updates to the working environment happen automatically, whereas, with Continuous Delivery, it happens with manual confirmation.
What do you know about Ansible Tool? Can you substitute it?
Ansible is a software solution for remote configuration management. It allows configuring remote machines. Its main difference from other similar systems is that Ansible uses the existing SSH infrastructure, while others ( Chef, Puppet, etc.) require the installation of a particular PKI environment. But this program can be replaced by analogs: DCImanager, Puppet, Salt, Chef, Fabric, cdist, etc.
What is Continuous Integration?
This question can be among DevOps interview questions. Continuous Integration is a technique that allows you to accelerate. Continuity is achieved by performing short steps; after each step, a standard set of actions is launched: building code, testing, and outputting the result. By Integration, we mean the joining of different pieces of code developed simultaneously by different developers.
What is Jenkins?
Jenkins is among DevOps services that implement DevOps practices. Jenkins is a “pipeline” of software delivery from the development environment to the production environment. The “pipeline” is, of course, conditional. Jenkins performs, step by step, the simplest operations on the code. Developers love Jenkins because it allows them to work with many tools. And it can also start a compilation in several different ways.
How to move Jenkins from one server to another?
There are two options:
А. Copy the entire Jobs folder and attached tasks. But then you will copy all the building history, logs, artifacts, etc.
B. Use Jenkins CLI to create exactly the same job – but “from scratch. “
How to secure Jenkins?
You can achieve security by restricting access to Jenkins files. The settings can configure authorization, configure who has which access, who can create jobs, etc.
How do you understand Containerization?
Containerization derives from the word container. A container is a storage space for “something”: a database, a website, a runtime environment for a programming language. Containerization is a technology that allows an application and all its associated files to be packaged in a single image. The container can be easily moved around and run in any operating system and working environment.
What is a Docker Hub?
Docker Hub is that remote repository where you can download the “image” you need. In this repository, you can later save your “images” to access them anywhere and share them with anyone.
What cloud platforms are used in DevOps?
Azure, AWS, Google Cloud
What is AWS?
AWS stands for Amazon Web Services. It is the world’s most popular cloud platform, providing the most comprehensive capabilities and full-featured services for data centers.
How do you build a Hybrid Cloud?
First, you need to gather the requirements and design a hybrid cloud. After that, choose a Cloud Provider. Next, the provider performs the configuration. Then you migrate part of the services and check their work. Finally, load testing of the Infrastructure is performed, and speed, reliability, and correctness of interaction are checked.
What are the benefits of CBD?
CBD stands for Component-Based Development. The advantage of component-based architectures is the ability of an application to evolve. In addition to the convenience and flexibility in upgrading existing applications, building programs from components has other advantages. They are related to the adaptation of applications to user needs, component libraries, and distributed parts.
Why is Automating Testing important?
Routine and frequent checkup automation reduces the workload of QA specialists. The AT allows monitoring of essential application functions and tracking of product changes. It permits testing with many devices, browser versions, and operating systems. Automation performs application performance testing under conditions of simultaneous operation with a large number of data and users. At the same time, automation reduces both testing costs and risks associated with the human factor in the long run.
What is Version Control System?
They are collaborative tools that allow you to keep a history of project changes. A version control system is needed so that developers can go back to a previous version if they break something in a later one. This tool allows them to move away from manual file storage. There are two types of VCS: centralized (when all changes are stored on a remote server) and distributed (when project history is stored not only on the central server but also on developers’ local computers). The main tools are Subversion and Git, respectively.
Name network monitoring tools you know.
Nagios, Cacti, WireShark, Observium, Zabbix, Icinga2. They allow you to react quickly to abnormal activity within the local network, to be aware of all the network processes, and thus automate part of the routine activities of the administrator: primarily those related to network security.
What can you tell about Selenium?
Selenium is a programmable browser driver. It is used in the context of automating web application testing. You can automate the preparation of test environments and data, and reporting of results. Partly, testers can automate the creation, execution and validation of tests. To run it, a specialist has to describe the actions to be performed and the reactions to specific events, and run the program. The Selenium WebDriver of the system under test is an integral part of testing because, without it, the event will not run. An alternative option for those who can not write in standard programming languages is the Selenium IDE, an add-on for the Firefox browser. It provides a set of commands that can be executed. For example, you can make a linear script using these commands.
Robyn McBride is a journalist, tech critic, author of articles about software, AI and design. She is interested in modern image processing, tech trends and digital technologies. Robyn also works as a proofreader at Computools.