# Kubernetes Patterns

> When to activate: Kubernetes, k8s, kubectl, deployment, pod, service, ingress, HPA, ConfigMap, Secret, namespace

- Skill: `mattakushi432/kubernetes-patterns` (Agent Skill)
- Install (CLI): `npx skillmds@latest add mattakushi432/kubernetes-patterns`
- Raw SKILL.md: https://api.skillmd.com/api/skills/mattakushi432/kubernetes-patterns/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: DevOps & Infra
- Author: Mattakushi432 (https://skillmd.com/u/mattakushi432)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/mattakushi432/kubernetes-patterns

---

# Kubernetes Patterns

## Deployment with Probes

```yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: myapp
  labels:
    app: myapp
spec:
  replicas: 3
  selector:
    matchLabels:
      app: myapp
  strategy:
    rollingUpdate:
      maxSurge: 1
      maxUnavailable: 0
  template:
    metadata:
      labels:
        app: myapp
    spec:
      containers:
        - name: myapp
          image: myapp:1.2.3
          ports:
            - containerPort: 8080
          resources:
            requests:
              cpu: 100m
              memory: 128Mi
            limits:
              cpu: 500m
              memory: 512Mi
          readinessProbe:
            httpGet:
              path: /ready
              port: 8080
            initialDelaySeconds: 5
            periodSeconds: 10
            failureThreshold: 3
          livenessProbe:
            httpGet:
              path: /health
              port: 8080
            initialDelaySeconds: 15
            periodSeconds: 20
          envFrom:
            - configMapRef:
                name: myapp-config
            - secretRef:
                name: myapp-secrets
```

## Service

```yaml
apiVersion: v1
kind: Service
metadata:
  name: myapp
spec:
  selector:
    app: myapp
  ports:
    - port: 80
      targetPort: 8080
  type: ClusterIP
```

## Ingress (nginx)

```yaml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: myapp
  annotations:
    nginx.ingress.kubernetes.io/rate-limit: "100"
    cert-manager.io/cluster-issuer: letsencrypt-prod
spec:
  ingressClassName: nginx
  tls:
    - hosts:
        - myapp.example.com
      secretName: myapp-tls
  rules:
    - host: myapp.example.com
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: myapp
                port:
                  number: 80
```

## HorizontalPodAutoscaler

```yaml
apiVersion: autoscaling/v2
kind: HorizontalPodAutoscaler
metadata:
  name: myapp
spec:
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: myapp
  minReplicas: 2
  maxReplicas: 10
  metrics:
    - type: Resource
      resource:
        name: cpu
        target:
          type: Utilization
          averageUtilization: 70
```

## PodDisruptionBudget

```yaml
apiVersion: policy/v1
kind: PodDisruptionBudget
metadata:
  name: myapp
spec:
  minAvailable: 2
  selector:
    matchLabels:
      app: myapp
```

## ConfigMap + Secret

```yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: myapp-config
data:
  LOG_LEVEL: info
  PORT: "8080"
---
apiVersion: v1
kind: Secret
metadata:
  name: myapp-secrets
type: Opaque
stringData:
  DATABASE_URL: postgres://user:pass@db:5432/myapp
  JWT_SECRET: changeme
```

## ResourceQuota (namespace level)

```yaml
apiVersion: v1
kind: ResourceQuota
metadata:
  name: team-quota
  namespace: team-a
spec:
  hard:
    requests.cpu: "4"
    requests.memory: 8Gi
    limits.cpu: "8"
    limits.memory: 16Gi
    pods: "20"
```

## Key Rules
- Always set resource requests AND limits
- Use `minAvailable` PDB to ensure availability during rolling updates
- Prefer `readinessProbe` over `livenessProbe` for startup — liveness restarts the pod
- Never use `latest` image tag in production
- Use `topologySpreadConstraints` to spread pods across AZs