This tutorial describes how to setup ExternalDNS for usage within a Kubernetes cluster using SafeDNS.
Make sure to use >=0.11.0 version of ExternalDNS for this tutorial.
If you want to learn about how to use the SafeDNS service read the following tutorials: To learn more about the use of SafeDNS in general, see the following page:
ANS Group's SafeDNS documentation.
Generate a fresh API token for use with ExternalDNS, following the instructions at the ANS Group developer Getting-Started page. You will need to grant read/write access to the SafeDNS API. No access to any other ANS Group service is required.
The environment variable SAFEDNS_TOKEN
must have a value of this token to run
ExternalDNS with SafeDNS integration.
Connect your kubectl
client to the cluster you want to test ExternalDNS with.
Then apply one of the following manifests file to deploy ExternalDNS.
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
# You will need to check what the latest version is yourself:
# https://github.com/kubernetes-sigs/external-dns/releases
image: registry.k8s.io/external-dns/external-dns:v0.14.2
args:
- --source=service # ingress is also possible
# (optional) limit to only example.com domains; change to match the
# zone created above.
- --domain-filter=example.com
- --provider=safedns
env:
- name: SAFEDNS_TOKEN
value: "SAFEDNSTOKENSAFEDNSTOKEN"
apiVersion: v1
kind: ServiceAccount
metadata:
name: external-dns
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
name: external-dns
rules:
- apiGroups: [""]
resources: ["services","endpoints","pods"]
verbs: ["get","watch","list"]
- apiGroups: ["extensions","networking.k8s.io"]
resources: ["ingresses"]
verbs: ["get","watch","list"]
- apiGroups: [""]
resources: ["nodes"]
verbs: ["list"]
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
name: external-dns-viewer
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: external-dns
subjects:
- kind: ServiceAccount
name: external-dns
namespace: default
---
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:
serviceAccountName: external-dns
containers:
- name: external-dns
image: registry.k8s.io/external-dns/external-dns:v0.14.2
args:
- --source=service # ingress is also possible
# (optional) limit to only example.com domains; change to match the
# zone created above.
- --domain-filter=example.com
- --provider=safedns
env:
- name: SAFEDNS_TOKEN
value: "SAFEDNSTOKENSAFEDNSTOKEN"
Create a service file called 'nginx.yaml' with the following contents:
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx
spec:
selector:
matchLabels:
app: nginx
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: my-app.example.com
spec:
selector:
app: nginx
type: LoadBalancer
ports:
- protocol: TCP
port: 80
targetPort: 80
Note the annotation on the service; use a hostname that matches the domain filter specified above.
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 SafeDNS records.
Check your SafeDNS UI and select the appropriate domain to view the records for your SafeDNS zone.
This should show the external IP address of the service as the A record for your domain.
Alternatively, you can perform a DNS lookup for the hostname specified:
$ dig +short my-app.example.com
an.ip.addr.ess
Now that we have verified that ExternalDNS will automatically manage SafeDNS records, we can delete the tutorial's example:
$ kubectl delete service -f nginx.yaml
$ kubectl delete service -f externaldns.yaml