Kubernetes

Production Kubernetes Orchestration Guide for Cloud Engineers

️ 1. Cluster Internals

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Can you explain how the Kubernetes Scheduler works under the hood? How does it choose the best node for a pod?

What is etcd, why is it critical to a Kubernetes cluster, and how does it maintain consistency?

# Key Characteristics:

What is the role of kube-proxy in a cluster? Can you compare IPTables mode versus IPVS mode?

# Modes of Operation:

How does CoreDNS facilitate service discovery inside a Kubernetes cluster?

What are the primary responsibilities of the Kubernetes API Server (kube-apiserver)?

CNI & Networking

Q10

What is a CNI plugin, and what actually happens when a pod is assigned an IP?

Q11

If you had to choose a CNI, how would you compare Calico, Cilium, Flannel, and Weave?

Q12

What is eBPF, and why is the Cilium CNI moving away from standard iptables in favor of it?

Q13

Walk me through the Kubernetes networking model. How do pods communicate with each other?

Q14

Explain how Service IP routing works under the hood. How does a virtual IP reach a real pod?

Q15

️ 1.6 Ingress & Gateway API

Q16

What is the difference between the legacy Ingress resource and the new Gateway API?

Q17

How does NGINX Ingress Controller process incoming traffic and apply routing changes?

Q18

What is an IngressClass and why would we run multiple ingress controllers?

Q19

If a user receives a 503 Service Unavailable, how would you troubleshoot the Ingress pathway?

Q20

Storage

Q21

What is a CSI Driver, and why did Kubernetes migrate away from in-tree storage plugins?

Q22

How do you explain the relationships between PersistentVolumes (PV), PersistentVolumeClaims (PVC), and StorageClasses?

Q23

How does dynamic storage provisioning work when a developer deploys a PVC?

Q24

If our database needs more disk space, how do you expand an active PVC?

Q25

AWS EKS Specifics

Q26

What is IAM Roles for Service Accounts (IRSA), and how does it secure pod access to AWS?

Q27

How does authentication and authorization work in an Amazon EKS cluster? How does AWS IAM map to Kubernetes RBAC?

Q28

What is the AWS Load Balancer Controller, and how does it integrate Services and Ingresses with AWS ALB/NLB?

Q29

How do you upgrade an AWS EKS cluster in production with zero downtime?

Q30

Workloads & Pod Controller Logic

Q31

What is the operational difference between a Deployment and a StatefulSet? When would you use one over the other?

Q32

What is a DaemonSet, and can you share a few real-world examples of when you would deploy one?

Q33

# Common Use Cases:

Q34

How does a Kubernetes Job differ from a CronJob? When is each appropriate?

Q35

What is a ReplicaSet, and why do we rarely manage ReplicaSets directly in production?

Q36

What are Init Containers, and how do they differ from standard sidecars in a Pod's lifecycle?

Q37

# Characteristics:

Q38

Advanced Pod Scheduling

Q39

How does Node Affinity work? What is the difference between required (hard) and preferred (soft) scheduling rules?

Q40

# Types of Affinity:

Q41

Can you explain the difference between Pod Affinity and Pod Anti-Affinity? Give me a scenario where you would use each.

Q42

What are Taints and Tolerations? How do they work together to control pod placements?

Q43

What is a Pod Disruption Budget (PDB), and how does it protect active workloads during maintenance?

Q44

What are Topology Spread Constraints, and how do they prevent single-zone or single-rack outages?

Q45

Cluster Security & Admission Control

Q46

Explain Kubernetes RBAC. What is the difference between a Role and a ClusterRole, and when would you use a RoleBinding over a ClusterRoleBinding?

Q47

What is a Service Account, and how does a pod use it to communicate securely with the Kubernetes API Server?

Q48

What is a Network Policy, and how do you implement a default-deny ingress rule in a namespace?

Q49

What are Pod Security Standards (PSS), and how do baseline and restricted profiles differ?

Q50

What are Admission Controllers? What is the difference between Mutating and Validating Admission Webhooks?

Q51

Cluster Autoscaling & Resource Allocation

Q52

How does the Horizontal Pod Autoscaler (HPA) compute desired replicas? Walk me through the mathematical formula it uses.

Q53

What is the Vertical Pod Autoscaler (VPA), and why can't we use it alongside the HPA on the same resource metrics?

Q54

How does the Cluster Autoscaler decide to scale node counts up or down? What events trigger these actions?

Q55

What is KEDA (Kubernetes Event-driven Autoscaling), and in what scenarios is it preferred over the standard HPA?

Q56

What are Resource Quotas, and how do they prevent a single tenant from starving other namespaces?

Q57

Scenario: Our cluster nodes are crashing under heavy load, causing application downtime. How would you design a highly available cluster infrastructure?

Q58

Scenario: We need to roll out updates to a high-traffic payment service with absolutely zero downtime. What is your deployment and routing strategy?

Q59

Scenario: Our cloud monthly bill is skyrocketing due to over-provisioned nodes. How would you optimize resource allocations for workloads?

Q60

Scenario: We are running Kubernetes across AWS, GCP, and on-premises datacenters. How do you manage and synchronize configurations across all clusters?

Q61

Scenario: We are storing database passwords as plaintext inside our environment configurations. How do you secure secrets in Kubernetes?

Q62

Scenario: We need to design a disaster recovery plan for our Kubernetes workloads. How do you implement a backup and restore strategy?

Q63

Scenario: Users are complaining that our application is slow, but CPU usage looks normal. How would you systematically diagnose this performance issue?

Q64

Scenario: We want to roll out a high-risk database-dependent update to 5% of users first. How do you configure a Canary deployment?

Q65

Scenario: Due to strict GDPR compliance, customer data cannot leave the EU. How do you configure our cluster to enforce data residency?

Q66

Scenario: We are migrating a monolithic e-commerce application to microservices on Kubernetes. How do you plan this migration?

Created by

Apurv Gujjar

DevOps & Cloud Engineer

Specialized in:DevOpsAWSGCPKubernetesTerraformDocker

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