Most Asked Docker and Kubernetes Interview Questions for the Candidates

As the demand for IT professionals with experience in containerization technologies such as Docker and Kubernetes increases, employers seek candidates who know how to use these tools to create and manage cloud-native applications.

In this article, we’ll look at the frequently asked 10 Docker and Kubernetes interview questions for freshers.

Interview Questions on Docker and Kubernetes 

• How does orchestration relate to software and DevOps?

Answer: Orchestration in software and DevOps is the process of automating the management and deployment of IT services, such as provisioning, configuration, patching, upgrades, and process orchestration. 

It helps to reduce manual effort, ensure high availability and scalability, and provide easier monitoring and management of services. Additionally, it allows for changes to be quickly rolled back if needed. 

• What is Google Container Engine intended for? 

Answer: Google Container Engine makes it effortless to create and manage clusters of virtual machines hosted on the Google Cloud Platform, leveraging the power of Google Kubernetes technology. With Container Engine, you can easily deploy and manage container-based applications on a cluster of machines. 

• What is the purpose of 'Heapster' in Kubernetes? 

Answer: Heapster is a performance monitoring and event tracking tool used in Kubernetes. It collects and aggregates performance metrics from all nodes in the Kubernetes cluster and provides an easy-to-use interface to query and visualise the collected data. It can also track events, such as when a pod is created, deleted, or updated.

• What is the link between Kubernetes and Docker? 

Answer: Kubernetes and Docker are both containerization technologies, but they are used for different purposes. Docker is used for packaging and running individual applications, while Kubernetes is used for managing and deploying those applications across multiple machines. 

Kubernetes can orchestrate, schedule, and manage Docker containers, making deploying, scaling, and managing applications easier. 

• What is the function of the master node in Kubernetes, and how does it work? 

Answer: The master node in Kubernetes is the control plane that manages and coordinates all nodes in the cluster, schedules workloads, and maintains the cluster's state. 

It communicates with the nodes using the Kubernetes API and manages the cluster's configuration, setting up networking, storage, and services and running the Kubernetes control plane components. 

• What are the key attributes of Docker? 

Answer: The key attributes of Docker include the following:

• Containerization: Docker provides a lightweight, portable, and secure way to package and deploy applications. 
• Scalability: It can easily scale up or down in response to changing demand. 
• Orchestration: With Docker, deploying and managing multiple containers is simple.
• Security: A secure environment for running applications is provided by Docker.
• Flexibility: It supports multiple platforms and languages, making developing and deploying applications easy. 
• Speed: Containers that Docker powers are fast to launch and can be quickly redeployed.
• Extensibility: Docker can be extended with plugins and APIs. 

• What are the primary disadvantages of using Docker? 

Answer: The primary disadvantages of using Docker are as follows:

• Lack of support for Windows: It is mainly used on Linux systems, and Windows users may need help to use it. 
• Limited networking capabilities: Docker containers are isolated from each other by default, so they don't have access to the same network resources as other containers or the host system. 
• Compatibility with existing systems: It may need to be compatible with certain existing systems, making it difficult to integrate into existing infrastructure.
• Security concerns: Docker containers can be vulnerable to malicious attacks, and users must be aware of these risks when running Docker containers.  

• How would you define the term "memory-swap flag"? 

Answer: The memory-swap flag in Docker is used to specify the total memory and swap memory available to a container. This flag can set a container's total memory and swap memory limits. 

This can be useful for ensuring that a container does not consume too much memory on the host system or for limiting the amount of swap memory available. 

• What do you understand by ETCD? 

Answer: Kubernetes uses ETCD to store, share and synchronise its data and configurations across nodes. Although ETCD was designed for use by CoreOS, it is open-source and can be used on multiple platforms such as Linux, BSB, and OS X. ETCD is the central source of truth for a Kubernetes cluster and keeps track of the cluster's state at any given time. 

• What is the definition of a Docker image? 

Answer: A Docker image is a preconfigured, read-only template that provides instructions for creating and running a container on a Docker engine. It contains all the necessary components and resources required to create and operate a container, such as software libraries, system tools, code, and runtime.

Overall, these are some of the most asked Kubernetes and Docker interview questions that give you a good understanding of the subject and the ability to answer questions related to it confidently.

Things to Keep in Mind Before You Go for an Interview

Preparing Kubernetes and Docker interview questions is a good start for an interview, but there are also other important things to consider. Before you proceed, consider the following: 

• Research the organisation and position for which you are applying.

• Dress professionally and bring several copies of your resume.

• Arrive early for the interview and be prepared to wait.

• Remain positive and confident throughout the interview.

• Ask relevant questions and show interest in the company.

• Demonstrate your knowledge and expertise. 

Conclusion

We hope the aforementioned top Docker and Kubernetes interview questions for developers have provided you with a thorough comprehension of the answers to your upcoming interview questions.

With Skill-Lync, you can learn more about the subject and better understand the technology. Our specialised courses available at can help you ace the upcoming interviews and make you successful. We also provide placement support and help you to prepare for interviews.

Talk yo our experts and book your free demo.