Creating DNS records on a public zone for Azure - External DNS Operator | Networking

Creating DNS records on an Azure public DNS zone

You can create DNS records on Azure by using the External DNS Operator.

Using the External DNS Operator on a {entra-first}-enabled cluster or a cluster that runs in Microsoft Azure Government (MAG) regions is not supported.

Creating DNS records on an Azure public DNS zone

You can create DNS records on a public DNS zone for Azure by using the External DNS Operator.

Prerequisites

You must have administrator privileges.
The admin user must have access to the kube-system namespace.

Procedure

Fetch the credentials from the kube-system namespace to use the cloud provider client by running the following command:

$ CLIENT_ID=$(oc get secrets azure-credentials  -n kube-system  --template={{.data.azure_client_id}} | base64 -d)
$ CLIENT_SECRET=$(oc get secrets azure-credentials  -n kube-system  --template={{.data.azure_client_secret}} | base64 -d)
$ RESOURCE_GROUP=$(oc get secrets azure-credentials  -n kube-system  --template={{.data.azure_resourcegroup}} | base64 -d)
$ SUBSCRIPTION_ID=$(oc get secrets azure-credentials  -n kube-system  --template={{.data.azure_subscription_id}} | base64 -d)
$ TENANT_ID=$(oc get secrets azure-credentials  -n kube-system  --template={{.data.azure_tenant_id}} | base64 -d)

$ az login --service-principal -u "${CLIENT_ID}" -p "${CLIENT_SECRET}" --tenant "${TENANT_ID}"

Get a list of routes by running the following command:

$ oc get routes --all-namespaces | grep console

Example output

openshift-console          console             console-openshift-console.apps.test.azure.example.com                       console             https   reencrypt/Redirect     None
openshift-console          downloads           downloads-openshift-console.apps.test.azure.example.com                     downloads           http    edge/Redirect          None

Get a list of DNS zones by running the following command:

$ az network dns zone list --resource-group "${RESOURCE_GROUP}"

Create a YAML file, for example, external-dns-sample-azure.yaml, that defines the ExternalDNS object:

Example external-dns-sample-azure.yaml file

apiVersion: externaldns.olm.openshift.io/v1beta1
kind: ExternalDNS
metadata:
  name: sample-azure (1)
spec:
  zones:
  - "/subscriptions/1234567890/resourceGroups/test-azure-xxxxx-rg/providers/Microsoft.Network/dnszones/test.azure.example.com" (2)
  provider:
    type: Azure (3)
  source:
    openshiftRouteOptions: (4)
      routerName: default (5)
    type: OpenShiftRoute (6)

1	Specifies the External DNS name.
2	Defines the zone ID.
3	Defines the provider type.
4	You can define options for the source of DNS records.
5	If the source type is `OpenShiftRoute`, you can pass the OpenShift Ingress Controller name. External DNS selects the canonical hostname of that router as the target while creating CNAME record.
6	Defines the `route` resource as the source for the Azure DNS records.

Check the DNS records created for OKD routes by running the following command:

$ az network dns record-set list -g "${RESOURCE_GROUP}"  -z test.azure.example.com | grep console

To create records on private hosted zones on private Azure DNS, you need to specify the private zone under the zones field which populates the provider type to azure-private-dns in the ExternalDNS container arguments.

Creating DNS records on Azure

Creating DNS records on an Azure public DNS zone