KCNA
Kubernetes and Cloud Native Associate
KCNACloud Native Architecture

Cloud Native Architecture

Cloud native is a design approach that fully exploits the advantages of cloud computing: elasticity, automation, resilience, and distributed systems.

CNCF & the Cloud Native Landscape

The Cloud Native Computing Foundation (CNCF) hosts and fosters projects across the cloud native landscape including Kubernetes, Prometheus, Envoy, Helm, Argo, and many more.

Cloud native principles:

  • Microservices — decompose into small, independently deployable services
  • Containers — portable, isolated packaging
  • Dynamic orchestration — automated placement and management
  • DevOps culture — CI/CD, infrastructure as code, shared ownership

The Twelve-Factor App

A methodology for building cloud-native apps:

FactorDescription
CodebaseOne codebase, many deploys
DependenciesExplicitly declare and isolate
ConfigStore config in environment variables
Backing servicesTreat as attached resources
Build/Release/RunStrictly separate stages
ProcessesExecute as stateless processes
Port bindingExport services via port binding
ConcurrencyScale via the process model
DisposabilityFast startup, graceful shutdown
Dev/prod parityKeep environments as similar as possible
LogsTreat as event streams
Admin processesRun as one-off processes

Microservices vs Monolith

MonolithMicroservices
DeploymentAll-or-nothingIndependent per service
ScalingScale everythingScale only what needs it
Failure isolationOne bug can crash allFailures are contained
ComplexitySimple initiallyNetwork, observability complexity

Service Mesh

A service mesh (Istio, Linkerd, Consul Connect) handles cross-cutting concerns:

  • mTLS between services
  • Traffic management (retries, circuit breaking, canary)
  • Observability (traces, metrics per service-to-service call)

Implemented via sidecar proxies (Envoy) injected into each Pod.

Serverless & Functions

  • Serverless: no server management, pay per invocation
  • FaaS (Function as a Service): AWS Lambda, Google Cloud Functions
  • Knative: serverless framework on Kubernetes

Helm: Kubernetes Package Manager

Helm packages K8s manifests into charts:

helm repo add bitnami https://charts.bitnami.com/bitnami
helm install my-postgres bitnami/postgresql
helm upgrade my-postgres bitnami/postgresql --set auth.password=newpass
helm rollback my-postgres 1

Summary

  • Cloud native means containers + dynamic orchestration + microservices + DevOps
  • CNCF hosts the key projects in the ecosystem
  • Service meshes add reliability and observability at the network layer
  • Helm simplifies deploying complex K8s applications
CertLab — KCNA & DCNA Revision