This tutorial describes how to setup ExternalDNS for usage within a Kubernetes cluster using Cloudflare DNS.
Make sure to use >=0.4.2 version of ExternalDNS for this tutorial.
We highly recommend to read this tutorial if you haven't used Cloudflare before:
Create a Cloudflare account and add a website
Snippet from Cloudflare - Getting Started:
Cloudflare's API exposes the entire Cloudflare infrastructure via a standardized programmatic interface. Using Cloudflare's API, you can do just about anything you can do on cloudflare.com via the customer dashboard.
The Cloudflare API is a RESTful API based on HTTPS requests and JSON responses. If you are registered with Cloudflare, you can obtain your API key from the bottom of the "My Account" page, found here: Go to My account.
The environment vars CF_API_KEY
and CF_API_EMAIL
will be needed to run ExternalDNS with Cloudflare.
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 created above.
- --provider=cloudflare
- --cloudflare-proxied # (optional) enable the proxy feature of Cloudflare (DDOS protection, CDN...)
env:
- name: CF_API_KEY
value: "YOUR_CLOUDFLARE_API_KEY"
- name: CF_API_EMAIL
value: "YOUR_CLOUDFLARE_EMAIL"
Create the deployment for ExternalDNS:
$ kubectl create -f externaldns.yaml
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 Cloudflare DNS zone created above. The annotation may also be a subdomain of the DNS zone (e.g. 'www.example.com').
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 Cloudflare DNS records.
Check your Cloudflare dasbhboard to view the records for your Cloudflare DNS zone.
Substitute the zone for the one created above if a different domain was used.
This should show the external IP address of the service as the A record for your domain.
Now that we have verified that ExternalDNS will automatically manage Cloudflare DNS records, we can delete the tutorial's example:
$ kubectl delete service -f nginx.yaml
$ kubectl delete service -f externaldns.yaml