Kubernetes Explained
Pods, nodes, services, and the Kubernetes control plane explained.
What is Kubernetes?
Kubernetes (K8s) is an open-source container orchestration platform. It automates deploying, scaling, and managing containerized applications across clusters of machines.
If Docker answers 'how do I run a container?', Kubernetes answers 'how do I run 1000 containers reliably, across 50 servers, with automatic restarts, load balancing, and rolling updates?'
Core objects
| Object | What it is |
|---|---|
| Pod | The smallest deployable unit — one or more containers that share networking and storage |
| Deployment | Manages a set of identical Pods — handles rolling updates and restarts |
| Service | A stable network endpoint for a set of Pods — handles load balancing |
| Ingress | Routes external HTTP/HTTPS traffic to Services |
| ConfigMap | Stores non-secret configuration data |
| Secret | Stores sensitive configuration data (passwords, tokens) |
| Namespace | Virtual cluster within a cluster — for organizing resources |
Architecture
A Kubernetes cluster has two types of nodes: control plane nodes (which manage the cluster) and worker nodes (which run your workloads).
Practice with TLD
The Kubernetes track starts with pod basics and progresses to debugging real cluster issues. Try k8s-fix-pod-crashloop to start.