Kubernetes & CKA Concepts

The container orchestration domain of the Digital Brain. Curated for the CKA Certification journey.

Core Concepts

PageDescription
CKA CertificationExam structure, domains, and preparation strategy
CKA Study RoadmapThe 40-day learning plan and daily schedule
Why Kubernetes?Why K8s exists: problems it solves and when NOT to use it
Kubernetes NamespacesLogical isolation, multi-tenancy, resource quotas, and default namespaces

Prerequisites

Architecture & Installation

PageDescription
Kubernetes ArchitectureControl Plane, Worker Nodes, component deep-dive, communication flows
Kind Cluster SetupLocal multi-node K8s cluster with Kind (Kubernetes IN Docker)

(More to be populated as ingestion progresses)

  • kubeadm Installation
  • High Availability (HA) Clusters
  • etcd Backup & Restore

Workloads & Scheduling

PageDescription
Pod FundamentalsPods: the smallest deployable unit, imperative vs declarative, YAML basics
Multi-Container PodsSidecar, init, adapter, and ambassador patterns; shared namespaces and volumes
Init ContainersPre-start setup, validation, and migration containers
Sidecar PatternAuxiliary containers for logging, monitoring, proxying, and TLS termination
Kubernetes Environment VariablesConfigMap, Secret, Downward API, and literal injection patterns
Pod Commands and ArgumentsOverriding ENTRYPOINT and CMD in container specs
Deployment, ReplicaSet & Replication ControllerWorkload controllers: self-healing, scaling, rolling updates, and rollback
Kubernetes DaemonSetNode-level workload: one Pod per node for monitoring, CNI, and agents
Kubernetes JobsBatch execution: finite tasks that run to completion with retry logic
Kubernetes CronJobsScheduled batch: time-based Job creation with cron expressions
Kubernetes Static PodsNode-local Pods managed by kubelet, used for control plane bootstrapping
Kubernetes Labels and SelectorsMetadata and query system that binds Services, controllers, and Pods
Kubernetes Manual SchedulingBypassing the scheduler with nodeName, nodeSelector, and taints/tolerations
Kubernetes Taints and TolerationsNegative scheduling: node taints, Pod tolerations, effects, and built-in taint catalog
Kubernetes Node AffinityAdvanced positive scheduling: rich operators, soft/hard constraints, and the taints+affinity production pattern

(More to be populated as ingestion progresses)

  • StatefulSets
  • Resource Quotas & Limits

Services & Networking

PageDescription
Kubernetes ServicesService abstraction, port concepts, Endpoints, and imperative commands
Kubernetes Service TypesDeep dive into ClusterIP, NodePort, LoadBalancer, and ExternalName

(More to be populated as ingestion progresses)

  • Ingress & Ingress Controllers
  • Network Policies
  • CoreDNS
  • CNI Plugins (Calico, Cilium, Flannel)

Storage

(To be populated as ingestion progresses)

  • Volumes & PersistentVolumes
  • PersistentVolumeClaims
  • StorageClasses
  • Stateful Storage Patterns

Security

(To be populated as ingestion progresses)

  • RBAC (Roles, RoleBindings, ClusterRoles)
  • Service Accounts
  • Pod Security Standards
  • TLS & Certificates

Troubleshooting

(To be populated as ingestion progresses)

  • Node & Pod Failure Diagnostics
  • Control Plane Troubleshooting
  • Networking Issues
  • Storage Failures

kubectl & CLI

(To be populated as ingestion progresses)

  • Essential kubectl Commands
  • kubectl Cheatsheet
  • Imperative vs Declarative Management

Tags: kubernetes cka devops containers scheduling networking security troubleshooting