Kubernetes Fundamentals

Kubernetes (K8s) is the industry standard container orchestration platform — automating deployment, scaling, and management of containerized applications across clusters of servers.

50 min•By Priygop Team•Last updated: Feb 2026

Core K8s Concepts

Pod — Smallest deployable unit. One or more containers sharing network/storage. Ephemeral (not directly managed)
Deployment — Manages replicas of pods. Handles rolling updates, rollbacks, desired state. kubectl rollout undo
Service — Stable network endpoint for pods. Types: ClusterIP (internal), NodePort (external), LoadBalancer (cloud LB)
Ingress — HTTP routing to services. Define rules: /api → api-service, /app → app-service. Works with Nginx/Traefik
ConfigMap / Secret — Configuration injection. ConfigMap for non-sensitive; Secret for passwords (base64, ideally encrypted)
HPA (Horizontal Pod Autoscaler) — Scale pods based on CPU/memory/custom metrics. Min 2, max 10 replicas
Namespace — Logical cluster isolation. Separate namespaces for dev/staging/production
Helm — Package manager for Kubernetes. Charts bundle all K8s manifests. helm install my-app ./chart

Kubernetes Manifests

Example

# deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: web-app
  namespace: production
spec:
  replicas: 3
  selector:
    matchLabels:
      app: web-app
  template:
    metadata:
      labels:
        app: web-app
    spec:
      containers:
        - name: web
          image: ghcr.io/myorg/web-app:latest
          ports:
            - containerPort: 3000
          env:
            - name: DATABASE_URL
              valueFrom:
                secretKeyRef:
                  name: app-secrets
                  key: database-url
          resources:
            requests:
              memory: "128Mi"
              cpu: "100m"
            limits:
              memory: "256Mi"
              cpu: "500m"
          livenessProbe:
            httpGet:
              path: /health
              port: 3000
            initialDelaySeconds: 30
            periodSeconds: 10
          readinessProbe:
            httpGet:
              path: /ready
              port: 3000

---
# service.yaml
apiVersion: v1
kind: Service
metadata:
  name: web-app
spec:
  selector:
    app: web-app
  ports:
    - port: 80
      targetPort: 3000

---
# hpa.yaml — Auto-scaling
apiVersion: autoscaling/v2
kind: HorizontalPodAutoscaler
metadata:
  name: web-app
spec:
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: web-app
  minReplicas: 2
  maxReplicas: 10
  metrics:
    - type: Resource
      resource:
        name: cpu
        target:
          type: Utilization
          averageUtilization: 70

Quick Quiz

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Core K8s Concepts

Pod — Smallest deployable unit. One or more containers sharing network/storage. Ephemeral (not directly managed)

Deployment — Manages replicas of pods. Handles rolling updates, rollbacks, desired state. kubectl rollout undo

Service — Stable network endpoint for pods. Types: ClusterIP (internal), NodePort (external), LoadBalancer (cloud LB)

Ingress — HTTP routing to services. Define rules: /api → api-service, /app → app-service. Works with Nginx/Traefik

ConfigMap / Secret — Configuration injection. ConfigMap for non-sensitive; Secret for passwords (base64, ideally encrypted)

HPA (Horizontal Pod Autoscaler) — Scale pods based on CPU/memory/custom metrics. Min 2, max 10 replicas

Namespace — Logical cluster isolation. Separate namespaces for dev/staging/production

Helm — Package manager for Kubernetes. Charts bundle all K8s manifests. helm install my-app ./chart

Kubernetes Manifests

Example

# deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: web-app
  namespace: production
spec:
  replicas: 3
  selector:
    matchLabels:
      app: web-app
  template:
    metadata:
      labels:
        app: web-app
    spec:
      containers:
        - name: web
          image: ghcr.io/myorg/web-app:latest
          ports:
            - containerPort: 3000
          env:
            - name: DATABASE_URL
              valueFrom:
                secretKeyRef:
                  name: app-secrets
                  key: database-url
          resources:
            requests:
              memory: "128Mi"
              cpu: "100m"
            limits:
              memory: "256Mi"
              cpu: "500m"
          livenessProbe:
            httpGet:
              path: /health
              port: 3000
            initialDelaySeconds: 30
            periodSeconds: 10
          readinessProbe:
            httpGet:
              path: /ready
              port: 3000

---
# service.yaml
apiVersion: v1
kind: Service
metadata:
  name: web-app
spec:
  selector:
    app: web-app
  ports:
    - port: 80
      targetPort: 3000

---
# hpa.yaml — Auto-scaling
apiVersion: autoscaling/v2
kind: HorizontalPodAutoscaler
metadata:
  name: web-app
spec:
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: web-app
  minReplicas: 2
  maxReplicas: 10
  metrics:
    - type: Resource
      resource:
        name: cpu
        target:
          type: Utilization
          averageUtilization: 70