This tutorial describes how to setup ExternalDNS for usage in conjunction with an ExternalName service.
The main use cases that inspired this feature is the necessity for having a subdomain pointing to an external domain. In this scenario, it makes sense for the subdomain to have a CNAME record pointing to the external domain.
apiVersion: apps/v1
kind: Deployment
metadata:
name: external-dns
spec:
strategy:
type: Recreate
selector:
matchLabels:
app: external-dns
template:
metadata:
labels:
app: external-dns
spec:
containers:
- name: external-dns
image: k8s.gcr.io/external-dns/external-dns:v0.7.6
args:
- --log-level=debug
- --source=service
- --source=ingress
- --namespace=dev
- --domain-filter=example.org.
- --provider=aws
- --registry=txt
- --txt-owner-id=dev.example.org
kind: Service
apiVersion: v1
metadata:
name: aws-service
annotations:
external-dns.alpha.kubernetes.io/hostname: tenant1.example.org,tenant2.example.org
spec:
type: ExternalName
externalName: aws.example.org
This will create 2 CNAME records pointing to aws.example.org
:
tenant1.example.org
tenant2.example.org
If externalName
is an IP address, External DNS will create A records instead of CNAME.
kind: Service
apiVersion: v1
metadata:
name: aws-service
annotations:
external-dns.alpha.kubernetes.io/hostname: tenant1.example.org,tenant2.example.org
spec:
type: ExternalName
externalName: 111.111.111.111
This will create 2 A records pointing to 111.111.111.111
:
tenant1.example.org
tenant2.example.org