Kubernetes External DNS with PowerDNS

Table of Contents

Pada panduan ini akan membahas cara mengonfigurasi external DNS di kluster Kubernetes. Dengan men-deploy external DNS di kluster, proses pengelolaan data DNS pada aplikasi, service, atau ingress dapat lebih efisien waktu.

Preparation:

Server DNS dengan PowerDNS dan PowerDNS-Admin.
MetalLB

Create the namespace
#

Buat namespace dengan nama external-dns-pdns

kubectl create namespace external-dns-pdns

Set Up ExternalDNS
#

Buat manifest RBAC yang terdiri dari beberapa resource seperti ServiceAccount, ClusterRole, dan ClusterRoleBinding.

apiVersion: v1
kind: ServiceAccount
metadata:
  name: external-dns
  namespace: external-dns-pdns
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: external-dns
rules:
- apiGroups: [""]
  resources: ["services","endpoints","pods"]
  verbs: ["get","watch","list"]
- apiGroups: ["extensions","networking.k8s.io"]
  resources: ["ingresses"]
  verbs: ["get","watch","list"]
- apiGroups: [""]
  resources: ["pods"]
  verbs: ["get","watch","list"]
- apiGroups: [""]
  resources: ["nodes"]
  verbs: ["list"]
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: external-dns-viewer
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: external-dns
subjects:
- kind: ServiceAccount
  name: external-dns
  namespace: external-dns-pdns

Selanjutnya buat resource deployment untuk men-deploy external DNS dengan PowerDNS.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: external-dns
  namespace: external-dns-pdns
spec:
  strategy:
    type: Recreate
  selector:
    matchLabels:
      app: external-dns
  template:
    metadata:
      labels:
        app: external-dns
    spec:
      # Only use if you're also using RBAC
      serviceAccountName: external-dns
      containers:
      - name: external-dns
        image: registry.k8s.io/external-dns/external-dns:v0.13.5
        args:
        - --source=service # or ingress or both
        - --provider=pdns
        - --pdns-server=http://192.168.100.31:8081 # Your PowerDNS API URL (eg. http://127.0.0.1:8081)
        - --pdns-api-key=7c354e13f2482cd821c715b563d5f90ea4a57a
        - --txt-owner-id=2023081202
        - --domain-filter=muterin.local 
        - --log-level=debug
        - --interval=30s

Ganti domain pada --domain-filter dengan domain yang ada di server DNS, sedangkan --txt-owner-id dapat dengan bebas Anda tentukan. Namun Saya sarankan untuk diisi dengan serial domain.

Pastikan status pod external-dns running. Jika status pod error, cek logs atau events kemungkinan ada kesalahan konfigurasi server.

kubectl logs -n external-dns-pdns pod/external-dns-xxx-xx
kubectl events -n external-dns-pdns pod/external-dns-xxx-xx

Testing and Verification
#

Test dengan cara membuat deployment menggunakan image nginxdemos/hello lalu buat service dengan menambahkan external-dns.alpha.kubernetes.io/hostname: pada bagian annotations.

apiVersion: v1
kind: Namespace
metadata:
  name: site
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: demo
  namespace: site
spec:
  replicas: 2
  selector:
    matchLabels:
      app: demo
  template:
    metadata:
      labels:
        app: demo
    spec:
      containers:
      - image: nginxdemos/hello
        name: hello
        ports:
        - containerPort: 80
          protocol: TCP
---
apiVersion: v1
kind: Service
metadata:
  annotations:
    external-dns.alpha.kubernetes.io/hostname: demo.muterin.local
  name: demo
  namespace: site
spec:
  externalTrafficPolicy: Cluster
  internalTrafficPolicy: Cluster
  ports:
  - name: http
    port: 80
    protocol: TCP
    targetPort: 80
  selector:
    app: demo
  type: LoadBalancer