external-dns-adguard

This project aims to be a mostly compatible implementation of external-dns but targeting AdGuard Home as the DNS provider. It is similar to and, in fact, inspired by the python version.

Features

• Annotation-based configuration allows custom hostnames per entity
• Persistent database to more accurately detect changes
• Annotation defaults to be compatible with external-dns (external-dns.alpha.kubernetes.io/hostname), but can be configured to anything
• Small memory footprint ~10MB

Configuration

The following environment variables can be configured:

Variables	Default	Description
MODE	DEV	If DEV then it will use the default kubeconfig file; if PROD then it will use the cluster service account
DATABASE_FILE	rules.db	The full path of the database file
ADGUARD_URL	localhost:8080	The URL of the AdGuard Home instance
ADGUARD_SCHEME	http	The protocol to use - either http or https
ADGUARD_USERNAME		The AdGuard Home username
ADGUARD_PASSWORD		The AdGuard Home password
ADGUARD_LOGGING	false	Controls whether verbose feedback of the AdGuard client is enabled
ANNOTATION	external-dns.alpha.kubernetes.io	The annotation to pull the hostnames from

Deployment

The application can be deployed with the sample deployment in [/deployment/deployment.yaml].

NOTE: The sample deployment manifest does not account for storage of the database, so a PVC should be created, or it will lose track of the mappings. This is not catastrophic, but it will prevent it from detecting changes to the hostname annotations, and it will leave behind stale entries in AdGuard.

Examples

Configuring a service to point sample.example.com to 192.168.123:

apiVersion: v1
kind: Service
metadata:
  annotations:
    external-dns.alpha.kubernetes.io/hostname: sample.example.com
  name: sample
spec:
  loadBalancerIP: 192.168.1.123
  ports:
    - nodePort: 32700
      port: 9000
      protocol: UDP
      targetPort: 19132
  selector:
    app.kubernetes.io/instance: sample
    app.kubernetes.io/name: sample
  sessionAffinity: None
  type: LoadBalancer

Configuring an ingress to point sample.example.com at the ingress controller's default IP:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    external-dns.alpha.kubernetes.io/hostname: sample.example.com
  name: sample
spec:
  ingressClassName: nginx
  rules:
    - host: sample.example.com
      http:
        paths:
          - backend:
              service:
                name: sample
                port:
                  name: http
            path: /
            pathType: Prefix

License

This code is released under the Apache License 2.0.