Dasar kubectl

Info Cluster

kubectl cluster-info
kubectl get nodes
kubectl config current-context
kubectl config use-context my-cluster

Perintah Utama

kubectl get <resource>	Tampilkan daftar resource
kubectl describe <resource> <name>	Info detail resource
kubectl create -f file.yaml	Buat resource dari file
kubectl apply -f file.yaml	Buat atau perbarui resource
kubectl delete -f file.yaml	Hapus resource dari file
kubectl edit <resource> <name>	Edit resource di tempat
kubectl api-resources	Tampilkan semua tipe resource

Format Output

-o wide	Kolom tambahan (IP, node)
-o yaml	Output YAML lengkap
-o json	Output JSON lengkap
-o jsonpath='{.spec}'	Ekstrak field tertentu
--sort-by=.metadata.name	Urutkan output berdasarkan field

Pod

Operasi Pod

kubectl get pods
kubectl get pods -A                  # all namespaces
kubectl run nginx --image=nginx      # quick pod
kubectl delete pod nginx

YAML Pod

apiVersion: v1
kind: Pod
metadata:
  name: myapp
  labels: { app: myapp }
spec:
  containers:
    - name: app
      image: nginx:1.27
      ports:
        - containerPort: 80

Nilai Status Pod

Running	Semua container sudah berjalan
Pending	Menunggu penjadwalan atau pull image
CrashLoopBackOff	Container terus crash dan restart
ImagePullBackOff	Gagal mengunduh image container
Completed	Selesai berjalan (Jobs)

Deployment

YAML Deployment

apiVersion: apps/v1
kind: Deployment
metadata:
  name: web
spec:
  replicas: 3
  selector:
    matchLabels: { app: web }
  template:
    metadata:
      labels: { app: web }
    spec:
      containers:
        - name: web
          image: nginx:1.27
          ports:
            - containerPort: 80

Perintah Deployment

kubectl get deploy	Tampilkan deployment
kubectl scale deploy web --replicas=5	Skala replica
kubectl set image deploy/web web=nginx:1.28	Update image (rolling)
kubectl rollout status deploy/web	Pantau progres rollout
kubectl rollout undo deploy/web	Rollback ke revisi sebelumnya
kubectl rollout history deploy/web	Lihat riwayat revisi

Service

Jenis Service

ClusterIP	Internal saja (default)
NodePort	Ekspos di IP setiap node pada port statis
LoadBalancer	Load balancer eksternal (cloud)
ExternalName	Alias DNS ke layanan eksternal

YAML Service

apiVersion: v1
kind: Service
metadata:
  name: web-svc
spec:
  type: ClusterIP
  selector: { app: web }
  ports:
    - port: 80
      targetPort: 80

Ekspos Cepat

kubectl expose deploy web --port=80 --type=ClusterIP
kubectl expose deploy web --port=80 --type=NodePort
kubectl get svc

ConfigMap & Secret

ConfigMap

kubectl create configmap app-cfg \
  --from-literal=DB_HOST=db.example.com \
  --from-file=config.ini

Secret

kubectl create secret generic db-creds \
  --from-literal=username=admin \
  --from-literal=password=s3cret

Penggunaan dalam Pod

# As environment variables
envFrom:
  - configMapRef: { name: app-cfg }
  - secretRef:    { name: db-creds }

# As volume mount
volumes:
  - name: cfg
    configMap: { name: app-cfg }

Perintah

kubectl get cm	Tampilkan ConfigMap
kubectl get secret	Tampilkan Secret
kubectl describe cm app-cfg	Tampilkan data ConfigMap
kubectl get secret db-creds -o yaml	Tampilkan Secret (base64-encoded)

Namespace

Perintah Namespace

kubectl get ns	Tampilkan namespace
kubectl create ns staging	Buat namespace
kubectl delete ns staging	Hapus namespace dan semua resource
kubectl get pods -n staging	Tampilkan pod di namespace
kubectl get pods -A	Tampilkan pod di semua namespace

Atur Namespace Default

kubectl config set-context --current \
  --namespace=staging

Volume

PersistentVolumeClaim

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: data-pvc
spec:
  accessModes: [ReadWriteOnce]
  resources:
    requests: { storage: 10Gi }

Mount dalam Pod

volumes:
  - name: data
    persistentVolumeClaim:
      claimName: data-pvc
containers:
  - volumeMounts:
      - name: data
        mountPath: /app/data

Jenis Volume

emptyDir	Direktori sementara, dihapus bersama pod
hostPath	Mount path filesystem host
persistentVolumeClaim	Penyimpanan persisten (PVC)
configMap	Mount ConfigMap sebagai file
secret	Mount Secret sebagai file

Ingress

YAML Ingress

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: web-ingress
spec:
  rules:
    - host: app.example.com
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: web-svc
                port: { number: 80 }

Catatan Ingress

Ingress Controller	Wajib ada (nginx-ingress, traefik, dll.)
pathType: Prefix	Cocokkan awalan URL
pathType: Exact	Cocokkan path URL tepat
TLS	Tambahkan bagian `tls:` dengan nama secret

Debugging

Perintah Diagnostik

kubectl logs <pod>	stdout/stderr container
kubectl logs <pod> -c <ctr>	Log container tertentu
kubectl logs <pod> --previous	Log dari container yang crash
kubectl describe pod <pod>	Event, kondisi, status
kubectl exec -it <pod> -- sh	Masuk shell ke container
kubectl port-forward <pod> 8080:80	Forward port lokal ke pod
kubectl top pods	Penggunaan CPU/memori (metrics-server)
kubectl get events --sort-by=.lastTimestamp	Timeline event cluster

Pod Debug

kubectl run debug --rm -it --image=busybox -- sh
# or attach ephemeral container
kubectl debug -it  --image=busybox

Pola Umum

Label & Selector

kubectl get pods -l app=web
kubectl get pods -l 'env in (prod,staging)'
kubectl label pod myapp env=prod

Batas Resource

resources:
  requests: { cpu: 100m, memory: 128Mi }
  limits:   { cpu: 500m, memory: 256Mi }

Liveness & Readiness

livenessProbe:
  httpGet: { path: /healthz, port: 8080 }
  initialDelaySeconds: 5
  periodSeconds: 10
readinessProbe:
  httpGet: { path: /ready, port: 8080 }

Resep Cepat

Dry run	`kubectl apply -f file.yaml --dry-run=client`
Generate YAML	`kubectl create deploy web --image=nginx --dry-run=client -o yaml`
Watch	`kubectl get pods -w`
Copy file	`kubectl cp file.txt pod:/tmp/`
Restart deploy	`kubectl rollout restart deploy/web`

REFERENSI CEPAT KUBERNETES