Setting up ExternalDNS for Services on TransIP¶
This tutorial describes how to setup ExternalDNS for usage within a Kubernetes cluster using TransIP.
Make sure to use >=0.5.14 version of ExternalDNS for this tutorial, have at least 1 domain registered at TransIP and enabled the API.
Enable TransIP API and prepare your API key¶
To use the TransIP API you need an account at TransIP and enable API usage as described in the knowledge base. With the private key generated by the API, we create a kubernetes secret:
Deploy ExternalDNS¶
Below are example manifests, for both cluster without or with RBAC enabled. Don’t forget to replace YOUR_TRANSIP_ACCOUNT_NAME
with your TransIP account name. In these examples, an example domain-filter is defined. Such a filter can be used to prevent ExternalDNS from touching any domain not listed in the filter. Refer to the docs for any other command-line parameters you might want to use.
Manifest (for clusters without RBAC enabled)¶
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: registry.k8s.io/external-dns/external-dns:v0.13.2
args:
- --source=service # ingress is also possible
- --domain-filter=example.com # (optional) limit to only example.com domains
- --provider=transip
- --transip-account=YOUR_TRANSIP_ACCOUNT_NAME
- --transip-keyfile=/transip/transip-api-key
volumeMounts:
- mountPath: /transip
name: transip-api-key
readOnly: true
volumes:
- name: transip-api-key
secret:
secretName: transip-api-key
Manifest (for clusters with RBAC enabled)¶
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: ["watch", "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:v0.13.2
args:
- --source=service # ingress is also possible
- --domain-filter=example.com # (optional) limit to only example.com domains
- --provider=transip
- --transip-account=YOUR_TRANSIP_ACCOUNT_NAME
- --transip-keyfile=/transip/transip-api-key
volumeMounts:
- mountPath: /transip
name: transip-api-key
readOnly: true
volumes:
- name: transip-api-key
secret:
secretName: transip-api-key
Deploying an Nginx Service¶
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; this is the name ExternalDNS will create and manage DNS records for.
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:
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 TransIP DNS records.
Verifying TransIP DNS records¶
Check your TransIP Control Panel to view the records for your TransIP DNS zone.
Click on 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.