A Kubernetes interview can be challenging if not prepared well. Having this in mind, we have prepared the following Kubernetes interview questions along with how best to answer them to help you ace your chances of succeeding in your interview. Let’s jump right in!
1. What Is Kubernetes?
Kubernetes are also known as k8s. It refers to a portable open-source container orchestration tool used to automate roles such as the scaling, monitoring, management, and deployment of containerized applications. Kubernetes deals with several containers which offer logical units to be managed and discovered. It disseminates application workloads to run on a cluster as well as automates dynamic container networking necessities. Kubernetes allocates storage and volumes to running containers, providing automatic scaling as well as maintaining the desired state of apps to provide resiliency.
2. Explain The Benefits Of Kubernetes For Companies
Kubernetes can help businesses to improve their application in the following:
- Reduce development, release, and deployment
It helps in the integration of containers and facilitation of the administration of storage resources from diverse providers
- Optimizes costs
Through its dynamic container administration, Kubernetes helps organizations save in ecosystem management and ensures scalability in diverse environments.
- It is flexible
Kubernetes is flexible in multi-cloud environments without performance or functional losses.
- It provides increased software availability and scalability
Depending on the organization’s needs, Kubernetes scales the underlying infrastructure and applications up or down.
3. Name Some Kubernetes Features
Some of the Kubernetes features include:
The declarative model works in the background to sustain the desired state
Auto-scaling – based on usage, it automatically scales applications and their resources up and down.
Resilience and self-healing- it provides auto replication, auto-scaling, auto restart, and auto replacement to enable application self-healing.
Lifecycle management-Automate updates to enable rollback to previous versions, and the ability to pause, and carry on a deployment.
Persistent storage- It has the ability to add and mount storage dynamically
Load balancing- it supports a wide range of external and internal load balancing options to address different needs.
4. Highlight The Major Components In Kubernetes
Kubernetes has three major components including:
Kube- a proxy- This provides a network proxy that runs on every node in a cluster to allow communication and maintain network rules.
Kubelet-This involve an agent that ensures that the containers required are running in a Kubernetes pod
Container runtime- This involves software that runs the containers. Kubernetes supports all the runtimes that comply with the Kubernetes container runtime interface.
5. What Are The Components That Manages Nodes, Control Communications, And Monitors The State Of A Kubernetes Cluster?
Kube-API server- it is responsible for exposing the Kubernetes API
Kube-scheduler- Examines new Kubernetes pods which do not have nodes to assign them to a node for implementation depending on policies, affinity specifications, and resources.
Kube- controller manager- provides a single binary where all controller functions are compiled.
Etcd- This is where all the data linked to the Kubernetes cluster are stored
6. Define The Term Container Orchestration
Container orchestration is an executable application component that automates the deployment, provision, availability, scaling, lifecycle management, and networking of containers. Container orchestration automates tasks needed to run containerized services and workload such as the operations that are important to the container life cycle.
7. Differentiate Between Docker And Kubernetes
Both Kubernetes and Docker are production-grade container orchestration platforms. However, they have different functionality and strength. Kubernetes installation is quite complex as compared to that of a Docker. Docker has limited functionality but is easier to learn while Kubernetes is more powerful but has a steep learning curve. Docker requires manual scaling while Kubernetes supports auto-scaling.
Kubernetes also requires a separate CLI tool while Docker requires an integrated CLI. Docker needs an auto load balancer but Kubernetes requires a manual setup load balancer.
8. Explain What Is The Ingress Network And How It Works
The ingress is a component that enables users to access Kubernetes services from the Kubernetes cluster. A user can design the access by formulating rules that describe which inbound connections reach which services.
The Ingress network provides the rules to handle external users’ access to the services present in the Kubernetes cluster using HTTPS or HTTP. Using this users can simply formulate rules for routing traffic even without making load balancers or displaying each service to the nodes.
9. Tell Us The Role Of The Kube-API server And Kube-Scheduler
The Kube-scheduler distributes and manages the workload on the worker nodes. It is responsible for selecting the suitable node to run the pod that is not scheduled based on necessary resources as well as monitoring resource utilization. The Kube-scheduler ensures that the workload isn’t scheduled on the already full nodes.
The Kube- API server is the front-end control that follows the scale-out architecture. This displays all APIs node components. It also establishes communication between the Kubernetes master component and the Kubernetes node.
10. Differentiate Between Replication Controller And Replica Set
The replication controller and replica set almost function the same since they both ensure that a certain number of pod replicas run at a specified time. The replication controller supports an equality-based selector only while the replica set supports the new-based selector. In the Replication controller, a rolling-update command is used for updating the replication controller. Hence replacing the specified replication controller with another new replication controller. On the other side, in replica set is used for updating the replica set. Thus, it is best used with deployments that make them declarative.
11. What Are The Uses Of Google Kubernetes Engine(Gk)?
There are several uses of GKE including:
- Debugging clusters of the Kubernetes container
- Resizing application controllers
- Creating docker container clusters
- Updating the clusters of a container
- Creating a replication controller, container pods, load balancer, jobs, or services
12. State Ways Of Providing API Security On Kubernetes
Some of the ways that offer API security include:
- Using API authentication
- Make sure that the traffic is secured by TLS
- Monitoring RBAC failures
- Using the newest version of Kube
- Eliminating default Service Account permissions
- Ensuring that Kubeless secures its API through authorization-mode=Webhook
- Using the right auth mode that has the API server authentication mode= Node, RBAC
- Make sure that the Kube dashboard employs a restrictive RBAC policy
- Enforcing a pod security policy for Kubernetes containers restrictions as well as the protection of the node
13. What Are Federated Clusters?
Federated clusters allow several Kubernetes clusters to be managed as a single cluster. In a data center or cloud, it is possible to construct several Kubernetes clusters and utilize a federation to govern and manage them all centrally. By using a single set of APIs on a hosting cluster, Kubernetes Cluster Federation enables you to coordinate the setup of several Kubernetes clusters. It is possible to describe which clusters should have their configuration handled and how they should be configured. The mechanisms offered by federated clusters are meant to serve as the basis for more complicated multicluster use cases, such as the deployment of multi-geographical applications and disaster recovery.
14. Define Cloud Controller Manager And Its Use In Kubernetes
This refers to the Kubernetes control plane component responsible for embedding cloud-specific control logic. The cloud controller manager separates the components that communicate with the cloud platform from those that only interface with your cluster and enables you to connect your cluster to the API of your cloud provider. The cloud-controller-manager component enables cloud providers to deploy features at a different pace compared to the main Kubernetes project. This is achieved by isolating the interoperability logic that exists between the Kubernetes and the underlying cloud architecture.
15. Give Some Practical Examples Of Security Measures For Kubernetes
Some practical examples of security measures for Kubernetes are auditing support, defining resource quotas, network segmentation, regular security updates, strict resource policies, offering restricted access to etcd, using images from authorized repositories, and regular scans for security vulnerabilities among others.
16. How Can You Monitor The Kubernetes Cluster?
A user can monitor the Kubernetes cluster by using Prometheus. The Prometheus ecosystem contains multiple components such as a client library for equipping application code, a push gateway for upholding short-lived jobs, and special purpose exporters for services such as HAproxy, StatsD, and Graphite, etc.
17. How Can You Get The Central Logs From POD?
This depends on the application and logging patterns such as streaming sidecar container, Node level logging agent, sidecar container consisting logging agent, and export logs from the apps. In the filebeat, journalbeat, and set up are running as daemonset. These logs are dumped into the Kafka topic which later dumps them to the ELK stack.
18. What Are The Types Of Kubernetes Volume?
Some of the popular types of Kubernetes volumes include:
EmptyDir- This type of volume is created when a pod is assigned to a node and it stays active provided the pod keeps running on that node.
Host path- This type of volume mounts a directory or file from the host node’s filesystem into the pod
Iscsi- this volume enables an existing Iscsi volume to be mounted into the pod
Flocker- this volume is used to manage data volumes. It enables a flicker dataset to be mounted into a pod. Nfs- this type of volume enables the existing network file system to be mounted into your pod. This volume does not allow data after the pod has been removed from the node. GCE persistent disk – This kind of volume mounts a GCE( google computer engine) persistent disk into the pod. It enables the data to remain intact after the pod is removed from the node.
19. Mention The List Of Objects Of Kubernetes
There are several objects used in Kubernetes such as replication sets and controllers, distinctive identities, deployments, stateful sets, daemon sets, jobs and cron jobs, and pods.
20. Highlight Tools For Container Orchestration
The container orchestration tools are :
- Apache Mesos- Apache Mesos is an open platform that manages workloads in a distributed manner through dynamic sharing between such applications.
- Kubernetes- Kubernetes is a portable open-source container orchestration tool used to automate roles such as the scaling, monitoring, management, and deployment of containerized applications
- Docker swarm- Docker swarm is a group of either virtual or physical machines that runs the docker apps. They have been designed to join together in a cluster. This allows the user to run the docker commands even though the group would be performed by the machines available in your cluster
21. Describe Your Experience Relating To The Role You Have Applied
I have been performing a similar role for six years now. During this time, I have gained a lot of skills in engaging the Kubernetes community. I have been using my engineering leadership abilities to guide teams on how to use python to provide exciting new features to thousands of users. I have been working to help build the next generation of container technology for cloud, devs, IoT, Edge, workstations, and clusters. Besides, I have the necessary experience to advocate and advance agile software development practices and create great engineering practices. In addition, I am passionate about open-source software, Kubernetes, Linux, and strong teams. I can build a meaningful, rewarding career working with great people in your company. I am eager to join you and assist to grow a healthy engineering culture that will comply with your company values.
22. What Qualities Do You Possess That Can Help You Perform This Role Effectively?
I believe that I am the best candidate for this job based on my strong qualities. I have six years of experience working with container networking and operating systems such as Linux. I am also familiar with technologies such as open-source software, Linux, Kubernetes, cloud, and Docker. Besides, I have strong communication, organizational, analysis, and problem-solving skills. Additionally, I have strong data analysis, technical, security, management, teamwork, communication, programming, leadership, and customer service skills.
23. What Roles Are You Expecting To Be Performing Should You Get This Job?
I had gone through your job posting for this role and I have familiarized myself with the roles that I will be expected to carry out. They include:
- Creating and leading a team of engineers through mentoring, coaching, hands-on career development, and feedback.
- promoting and advancing modern, agile software development practices
- Grow a collaborative, healthy engineering culture that will comply with the set company values
- Advocating for timely delivery of technical solutions that manage business needs
- Creating and supporting great organizational and engineering practices
- Participating in engineering process through architectural and code review
- Engaging with other teams such as commercial partners and open source community
- Ensuring there are quality engineering practices that guide a large team of engineers building Kubernetes offerings
- Setting and managing expectations of senior management, external stakeholders, and other engineering teams
24. What Are The Different Services Within Kubernetes?
Kubernetes offer different services including:
- Cluster IP service – This is the most used type of service. Kubernetes assigns an IP address to a cluster Ip service to enable the service to be reachable within a certain cluster. However, this service does not allow the user to make requests to pods from outside the cluster. It is mostly used for inter-service communication in the cluster.
- Node Port service- this is a cluster service extension upon which the Node Port service routes are created. It is a type of service that displays the service outside the cluster. It is used when a user wants to support external connectivity to her or his service.
- External Name service- This is used to build a service in the Kubernetes to expose an external data store such as the one that runs outside the Kubernetes.
- Load Balancer service- This is a type of service that is used by a user while he or she is using a cloud provider to host a Kubernetes cluster.
25. What Makes You Be The Most Suitable Candidate For This Job?
Besides having a bachelor’s degree in computer science, I’m knowledgeable about software development. I am passionate about helping others develop and grow in their career too. I am also excited about leading, coaching, mentoring, and managing software developers. Having worked in a similar role for six years now, I have gained a lot of experience working in agile development, cloud technologies, and containers. I focus on success as well as the delivery of high-quality software in the given time frame. I have a great understanding of Docker, Kubernetes, containers, and modern Linux. As a software developer, I possess excellent verbal and written technical communication skills. Furthermore, I have strong organizational, problem-solving, data analysis, technical, security, management, teamwork, programming, leadership, and customer service skills. Should I get this job, I will use my experience, education, qualities, and skills to exceed your expectation for this role.
The questions above along with the sample answers provided give you a snapshot of what to expect during a Kubernetes interview. However, you will need to check the websites to get an insight into the working culture of the company. This will help you to figure out any questions that may be asked by the hiring manager during the interview.