In today’s cloud-native ecosystem, Kubernetes has evolved from a “nice-to-know” tool to a strategic competency. Whether you're interviewing for a DevOps, Cloud Engineer, SRE, or Platform Engineer role, expect deep-dive discussions on architecture, troubleshooting, scalability, and production-grade deployments.
Below is a structured, interview-focused guide covering foundational to advanced Kubernetes questions with concise, practical answers.
- What is Kubernetes?
Answer:
Kubernetes is an open-source container orchestration platform designed to automate deployment, scaling, and management of containerized applications. It abstracts infrastructure complexity and provides declarative configuration, self-healing, and auto-scaling capabilities.
Originally developed by Google and now maintained by the Cloud Native Computing Foundation (CNCF).
- What are the Main Components of Kubernetes Architecture?
? Control Plane Components
- kube-apiserver – Entry point for all API requests
- etcd – Key-value store for cluster state
- kube-scheduler – Assigns pods to nodes
- kube-controller-manager – Manages controllers (ReplicaSet, Node, etc.)
- cloud-controller-manager – Integrates with cloud providers
? Node Components
- kubelet – Ensures containers are running in a Pod
- kube-proxy – Handles networking rules
- Container runtime – e.g., containerd
- What is a Pod?
Answer:
A Pod is the smallest deployable unit in Kubernetes. It encapsulates one or more containers that:
- Share network namespace
- Share storage volumes
- Run on the same node
Pods are ephemeral — they are not meant to be long-lived entities.
- What is the Difference Between Deployment and StatefulSet?
Feature | Deployment | StatefulSet |
Use Case | Stateless apps | Stateful apps |
Pod Identity | Random | Stable, unique identity |
Storage | Shared/ephemeral | Persistent per Pod |
Scaling | Parallel | Ordered |
Use StatefulSet for databases like MySQL, MongoDB, Kafka.
- What is a ReplicaSet?
Answer:
ReplicaSet ensures a specified number of Pod replicas are running at all times. If a Pod crashes, it automatically creates a new one.
Typically managed indirectly via a Deployment.
- What is a Service in Kubernetes?
Answer:
A Service provides stable networking and load balancing for Pods.
Types of Services:
- ClusterIP – Internal communication
- NodePort – Exposes service on node IP
- LoadBalancer – Cloud load balancer integration
- ExternalName – DNS aliasing
- What is the Difference Between ConfigMap and Secret?
Feature | ConfigMap | Secret |
Use Case | Non-sensitive config | Sensitive data |
Storage | Plain text | Base64 encoded |
Examples | App config | DB passwords, tokens |
- What is a Namespace?
Answer:
A Namespace logically separates cluster resources. It enables multi-tenant environments and resource isolation.
