Kubernetes Rundown
What it does
Kubernetes (K8s) is a container orchestration platform that automates deploying, scaling, and managing containerized applications across clusters of machines.
Think of it as an operating system for your cluster - you tell it what you want to run (containers), and it figures out where to run them, keeps them healthy, scales them up/down, and handles networking between them.
When itâs useful
Good fit for:
- Running multiple microservices that need to work together
- Applications that need high availability and automatic failover
- Services that need to scale dynamically based on load
- Teams managing many containers across multiple servers
- Production workloads that require zero-downtime deployments
- Multi-environment setups (dev, staging, prod) with consistent configuration
Overkill for:
- Simple single-server applications
- Static websites or small projects
- When youâre just learning Docker
- Teams with 1-2 developers and simple deployment needs
The rule of thumb: If youâre managing more than ~5-10 containers or need features like auto-scaling, self-healing, and rolling updates, K8s starts making sense.
How people commonly use it
Typical workflow:
- Develop locally - Write application code, create Dockerfile
- Build container images - Package app into Docker images
- Write K8s manifests - Define what you want to run (YAML files)
- Deploy to cluster - Apply manifests with
kubectl apply - Monitor and manage - Check logs, scale services, update deployments
Common use cases:
- Microservices architectures - Run dozens of interconnected services
- CI/CD pipelines - Automated deployments on code changes
- Batch jobs - Run scheduled tasks or data processing
- Stateful applications - Databases, message queues (though trickier)
- Multi-cloud deployments - Same setup works on AWS, GCP, Azure
Deployment patterns:
- Rolling updates (gradually replace old versions)
- Blue-green deployments (run two versions, switch traffic)
- Canary releases (test new version with small % of traffic)
Essential skills for intermediate level
Core concepts you must understand:
1. Container basics
- How Docker works (images, containers, registries)
- Writing Dockerfiles
- Container networking and storage basics
2. Key Kubernetes resources
- Pods - Smallest deployable unit (one or more containers)
- Deployments - Manage replicated applications
- Services - Expose pods to network traffic (ClusterIP, NodePort, LoadBalancer)
- ConfigMaps & Secrets - Configuration and sensitive data
- Namespaces - Logical cluster divisions
- Ingress - HTTP/HTTPS routing to services
- Persistent Volumes - Storage that survives pod restarts
3. YAML proficiency
- Read and write Kubernetes manifests
- Understand the structure (apiVersion, kind, metadata, spec)
- Debug YAML syntax errors
4. kubectl command line
kubectl get/describe/logs/exec/apply/delete- Debugging: checking pod status, viewing logs, accessing containers
- Port forwarding for local testing
5. Networking fundamentals
- How pods communicate with each other
- Service discovery (DNS)
- Load balancing basics
- Understanding ClusterIP vs NodePort vs LoadBalancer
6. Architecture understanding
- Control plane components (API server, scheduler, controller manager)
- Node components (kubelet, kube-proxy)
- How the declarative model works (desired state vs actual state)
7. Practical operations
- Rolling updates and rollbacks
- Scaling applications (manual and basic auto-scaling)
- Health checks (liveness and readiness probes)
- Resource limits (CPU/memory requests and limits)
- Basic troubleshooting (pod crashes, image pull errors, networking issues)
Nice to have (intermediateâadvanced):
- Helm (package manager for K8s)
- Monitoring with Prometheus/Grafana
- Log aggregation (ELK, Loki)
- Security basics (RBAC, network policies, pod security)
- StatefulSets for databases
- CI/CD integration (Jenkins, GitLab, ArgoCD)
Learning path:
- Start small - Run Minikube or kind locally
- Deploy simple apps - Static website, then basic API
- Learn by breaking things - Delete pods, crash containers, see what happens
- Read othersâ manifests - Study real-world examples on GitHub
- Build something real - Personal project with 2-3 microservices
- Get certified - CKA (Certified Kubernetes Administrator) forces hands-on learning
The key is that K8s has a steep learning curve, but once concepts click, itâs incredibly powerful. Most people need 2-3 months of regular use to feel comfortable.