external-dns-technitium-webhook

Warning

This is homelab quality software, and not meant for production usage. You have been warned.

External-dns-technitium-webhook is an ExternalDNS webhook to integrate it with Technitium DNS.

Usage

The application expects all configuration to be passed in via environment variables.

Environment Variable	Description
LISTEN_ADDRESS	The address the webhook server binds to (defaults to 0.0.0.0).
LISTEN_PORT	The port the webhook server listens ono (defaults to 3000).
TECHNITIUM_URL	The URL of the Technitium DNS server (required).
TECHNITIUM_USERNAME	The username to authenticate with the Technitium DNS server (required).
TECHNITIUM_PASSWORD	The password to authenticate with the Technitium DNS server (required).
ZONE	The zone to manage (e.g. example.com, required).
DOMAIN_FILTERS	A semicolon-separated list of domain filters to apply (e.g. foo.example.com;bar.example.com, optional).

Zone Handling

If the specified ZONE doesn't exist in Technitium DNS, it will be created automatically when the application starts.

The zone created will be of Forward type, with forwarder to this-server and DNSSEC validation enabled. This means that if the record doesn't exist in the zone on Technitium DNS, the internal resolver will be used and the DNS servers on the internet will be consulted.

Example Kubernetes Deployment

When deploying on kubernetes, the Technitium DNS webhook can be deployed as a sidecar to the external-dns deployment.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: external-dns-technitium-dns
  namespace: external-dns
  labels:
    app.kubernetes.io/name: external-dns
spec:
  strategy:
    type: Recreate
  selector:
    matchLabels:
      app.kubernetes.io/name: external-dns
  template:
    metadata:
      labels:
        app.kubernetes.io/name: external-dns
    spec:
      serviceAccountName: external-dns
      containers:
        - name: external-dns
          image: registry.k8s.io/external-dns/external-dns
          args:
            - --source=service
            - --source=ingress
            - --registry=noop
            - --provider=webhook
            - --webhook-provider-url=http://localhost:5580
        - name: webhook
          image: ghcr.io/roosmaa/external-dns-technitium-webhook
          env:
            - name: RUST_LOG
              value: "external_dns_technitium_webhook=info"
            - name: LISTEN_PORT
              value: "5580"
            - name: TECHNITIUM_URL
              value: "http://technitium-dns-dashboard.dns.svc.cluster.local:5380"
            - name: ZONE
              value: "example.com"
          envFrom:
            - secretRef:
                name: technitium-dns
          resources:
            requests:
              cpu: 1m
              memory: 10Mi
          readinessProbe:
            httpGet:
              port: 5580
              path: /health
            failureThreshold: 1
---
kind: Secret
type: Opaque
apiVersion: v1
stringData:
  TECHNITIUM_USERNAME: admin
  TECHNITIUM_PASSWORD: admin
metadata:
  name: technitium-dns
  namespace: external-dns