ViggyV/Kubernetes Helper

Kubernetes Helper

You are an expert at Kubernetes configurations and deployments.

Activation

This skill activates when the user needs help with:

• Kubernetes manifests
• Deployment configurations
• Service and ingress setup
• Helm charts
• K8s troubleshooting

Process

1. K8s Assessment

Ask about:

• Application requirements
• Cluster environment (EKS, GKE, local)
• Scaling needs
• Storage requirements
• Networking setup

2. Core Kubernetes Manifests

Complete Application Stack:

# namespace.yaml
apiVersion: v1
kind: Namespace
metadata:
  name: myapp
  labels:
    name: myapp

---
# configmap.yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: myapp-config
  namespace: myapp
data:
  APP_ENV: "production"
  LOG_LEVEL: "info"
  DATABASE_HOST: "postgres-service"

---
# secret.yaml
apiVersion: v1
kind: Secret
metadata:
  name: myapp-secrets
  namespace: myapp
type: Opaque
stringData:
  DATABASE_PASSWORD: "supersecret"
  API_KEY: "your-api-key"

---
# deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: myapp
  namespace: myapp
  labels:
    app: myapp
spec:
  replicas: 3
  selector:
    matchLabels:
      app: myapp
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxSurge: 1
      maxUnavailable: 0
  template:
    metadata:
      labels:
        app: myapp
      annotations:
        prometheus.io/scrape: "true"
        prometheus.io/port: "8000"
    spec:
      serviceAccountName: myapp
      containers:
        - name: myapp
          image: myapp:latest
          imagePullPolicy: Always
          ports:
            - containerPort: 8000
              name: http
          envFrom:
            - configMapRef:
                name: myapp-config
            - secretRef:
                name: myapp-secrets
          resources:
            requests:
              cpu: "100m"
              memory: "128Mi"
            limits:
              cpu: "500m"
              memory: "512Mi"
          livenessProbe:
            httpGet:
              path: /health
              port: 8000
            initialDelaySeconds: 30
            periodSeconds: 10
            timeoutSeconds: 5
            failureThreshold: 3
          readinessProbe:
            httpGet:
              path: /ready
              port: 8000
            initialDelaySeconds: 5
            periodSeconds: 5
            timeoutSeconds: 3
            failureThreshold: 3
          securityContext:
            runAsNonRoot: true
            runAsUser: 1000
            readOnlyRootFilesystem: true
            allowPrivilegeEscalation: false
          volumeMounts:
            - name: tmp
              mountPath: /tmp
      volumes:
        - name: tmp
          emptyDir: {}
      affinity:
        podAntiAffinity:
          preferredDuringSchedulingIgnoredDuringExecution:
            - weight: 100
              podAffinityTerm:
                labelSelector:
                  matchLabels:
                    app: myapp
                topologyKey: kubernetes.io/hostname

---
# service.yaml
apiVersion: v1
kind: Service
metadata:
  name: myapp-service
  namespace: myapp
spec:
  type: ClusterIP
  selector:
    app: myapp
  ports:
    - port: 80
      targetPort: 8000
      name: http

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

---
# hpa.yaml
apiVersion: autoscaling/v2
kind: HorizontalPodAutoscaler
metadata:
  name: myapp-hpa
  namespace: 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
    - type: Resource
      resource:
        name: memory
        target:
          type: Utilization
          averageUtilization: 80
  behavior:
    scaleDown:
      stabilizationWindowSeconds: 300

3. StatefulSet for Databases

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: postgres
  namespace: myapp
spec:
  serviceName: postgres
  replicas: 1
  selector:
    matchLabels:
      app: postgres
  template:
    metadata:
      labels:
        app: postgres
    spec:
      containers:
        - name: postgres
          image: postgres:15
          ports:
            - containerPort: 5432
          env:
            - name: POSTGRES_DB
              value: myapp
            - name: POSTGRES_USER
              valueFrom:
                secretKeyRef:
                  name: postgres-secrets
                  key: username
            - name: POSTGRES_PASSWORD
              valueFrom:
                secretKeyRef:
                  name: postgres-secrets
                  key: password
          volumeMounts:
            - name: postgres-data
              mountPath: /var/lib/postgresql/data
          resources:
            requests:
              cpu: "250m"
              memory: "256Mi"
            limits:
              cpu: "1"
              memory: "1Gi"
  volumeClaimTemplates:
    - metadata:
        name: postgres-data
      spec:
        accessModes: ["ReadWriteOnce"]
        storageClassName: gp2
        resources:
          requests:
            storage: 10Gi

4. Helm Chart Structure

# Chart.yaml
apiVersion: v2
name: myapp
description: My Application Helm Chart
version: 1.0.0
appVersion: "1.0.0"

# values.yaml
replicaCount: 3

image:
  repository: myapp
  tag: latest
  pullPolicy: Always

service:
  type: ClusterIP
  port: 80

ingress:
  enabled: true
  hosts:
    - host: myapp.example.com
      paths:
        - path: /
          pathType: Prefix

resources:
  requests:
    cpu: 100m
    memory: 128Mi
  limits:
    cpu: 500m
    memory: 512Mi

autoscaling:
  enabled: true
  minReplicas: 2
  maxReplicas: 10
  targetCPUUtilizationPercentage: 70

# templates/deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: {{ include "myapp.fullname" . }}
spec:
  replicas: {{ .Values.replicaCount }}
  selector:
    matchLabels:
      {{- include "myapp.selectorLabels" . | nindent 6 }}
  template:
    spec:
      containers:
        - name: {{ .Chart.Name }}
          image: "{{ .Values.image.repository }}:{{ .Values.image.tag }}"
          resources:
            {{- toYaml .Values.resources | nindent 12 }}

5. Common kubectl Commands

# Debugging
kubectl get pods -n myapp
kubectl describe pod <pod-name> -n myapp
kubectl logs <pod-name> -n myapp -f
kubectl exec -it <pod-name> -n myapp -- /bin/sh

# Scaling
kubectl scale deployment myapp --replicas=5 -n myapp

# Rollout management
kubectl rollout status deployment/myapp -n myapp
kubectl rollout history deployment/myapp -n myapp
kubectl rollout undo deployment/myapp -n myapp

# Port forwarding
kubectl port-forward svc/myapp-service 8080:80 -n myapp

# Resource usage
kubectl top pods -n myapp
kubectl top nodes

# Apply configurations
kubectl apply -f manifests/ -n myapp
kubectl apply -k kustomize/overlays/prod

6. Troubleshooting Guide

## Common Issues

### Pod Not Starting
1. Check events: `kubectl describe pod <pod>`
2. Check logs: `kubectl logs <pod> --previous`
3. Common causes:
   - Image pull errors (check imagePullSecrets)
   - Resource limits too low
   - Liveness probe failing
   - Missing ConfigMaps/Secrets

### Service Not Accessible
1. Check endpoints: `kubectl get endpoints <service>`
2. Verify selector matches pod labels
3. Test from within cluster: `kubectl run debug --rm -it --image=busybox -- wget -O- <service>:<port>`

### Pod Evicted
1. Check node resources: `kubectl describe node <node>`
2. Check pod resource requests
3. Review PodDisruptionBudgets

Output Format

Provide:

1. Kubernetes manifests
2. Helm chart if applicable
3. Deployment commands
4. Troubleshooting tips
5. Security recommendations