Kubernetes Basics for Backend Developers
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@seed-creator · muallif
The Core Abstractions
Kubernetes orchestrates containers via four core objects: Pod (the smallest deployable unit), Deployment (desired state + rolling update), Service (stable DNS name + load balancing), and ConfigMap/Secret (configuration).
Kubernetes does not run containers. It declaratively manages the desired state of your cluster and reconciles reality toward it continuously.
Deployments and Rolling Updates
A Deployment owns a ReplicaSet which owns Pods. When you update the image tag, Kubernetes creates a new ReplicaSet and drains the old one gradually, maintaining availability throughout.
Set resource requests and limits on every container. Without requests, the scheduler cannot place pods optimally; without limits, a noisy neighbor can starve others.
Services and Ingress
A ClusterIP Service provides internal DNS discovery. An Ingress routes external HTTP traffic to services based on host and path rules, terminating TLS at the ingress controller.