Setting up ExternalDNS for Services on Dnsimple

This tutorial describes how to setup ExternalDNS for usage within a Kubernetes cluster using Dnsimple.

Make sure to use >=0.4.6 version of ExternalDNS for this tutorial.

Creating Dnsimple Credentials

Instructions on creating your token Dnsimple - API Access Token:

The environment var DNSIMPLE_OAUTH will need to be set to your API Access token to run ExternalDNS with Dnsimple.

Deploy ExternalDNS

Create a deployment file called externaldns.yaml with the following contents:

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: external-dns
spec:
  strategy:
    type: Recreate
  template:
    metadata:
      labels:
        app: external-dns
    spec:
      containers:
      - name: external-dns
        image: registry.opensource.zalan.do/teapot/external-dns:v0.4.8
        args:
        - --source=service # ingress is also possible
        - --domain-filter=example.com # (optional) limit to only example.com domains; change to match the zone you create in dnsimple.
        - --provider=dnsimple
        - --registry=txt
        env:
        - name: DNSIMPLE_OAUTH
          value: "YOUR_DNSIMPLE_API_KEY"

Create the deployment for ExternalDNS:

$ kubectl create -f externaldns.yaml

Deploying an Nginx Service

Create a service file called 'nginx.yaml' with the following contents:

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: nginx
spec:
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - image: nginx
        name: nginx
        ports:
        - containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
  name: nginx
  annotations:
    external-dns.alpha.kubernetes.io/hostname: example.com
spec:
  selector:
    app: nginx
  type: LoadBalancer
  ports:
    - protocol: TCP
      port: 80
      targetPort: 80

Note the annotation on the service; use the same hostname as the zone you create in Dnsimple.

ExternalDNS uses this annotation to determine what services should be registered with DNS. Removing the annotation will cause ExternalDNS to remove the corresponding DNS records.

Create the deployment and service:

$ kubectl create -f nginx.yaml

Depending where you run your service it can take a little while for your cloud provider to create an external IP for the service.

Once the service has an external IP assigned, ExternalDNS will notice the new service IP address and synchronize the Dnsimple DNS records.

Verifying Dnsimple DNS records

Would appreciate some help with this step.

Cleanup

Now that we have verified that ExternalDNS will automatically manage Dnsimple DNS records, we can delete the tutorial's example:

$ kubectl delete service -f nginx.yaml
$ kubectl delete service -f externaldns.yaml