Install ExternalDNS in Workload Clusters Deployed by a Supervisor

This topic explains how to deploy ExternalDNS to Tanzu Kubernetes Grid (TKG) workload clusters deployed to vSphere by a vSphere with Tanzu Supervisor.

External DNS allows for DNS records to be created automatically for Kubernetes services with an ingress component such as Contour with Envoy. The ExternalDNS package is validated with the following DNS providers: AWS (Route 53), Azure DNS, and RFC2136-compliant DNS servers (such as BIND).

You can install External DNS on a workload cluster in two ways:

Using the Tanzu CLI
Using kubectl

Install ExternalDNS Using the Tanzu CLI

Prerequisites

Adhere to the following prerequisites.

Reference

Refer to the following topic as needed.

ExternalDNS Components, Configuration, Data Values.

Install ExternalDNS

Complete these steps to install the ExternalDNS package on a TKG cluster.

Create the namespace for ExternalDNS.

kubectl create ns tanzu-system-service-discovery

Use Kubectl to list the packages and their versions available in the repository.
```
kubectl -n tkg-system get packages
```
The latest available package in the repository is 0.11.0+vmware.1-tkg.2. This is the version to install.
If necessary, create a configmap that defines the DNS server the ExternalDNS package will interface with.

See ExternalDNS Components, Configuration, Data Values for an example.
Create a data values specification for the ExternalDNS package for your chosen DNS provider.

See External DNS Configuration Parameters for a full list of available parameters.

Install the ExternalDNS package using the Tanzu CLI.

tanzu package install external-dns -p external-dns.tanzu.vmware.com -n tanzu-system-service-discovery -v 0.11.0+vmware.1-tkg.2 --values-file external-dns-data-values.yaml

Verify that the package is installed using the Tanzu CLI.

tanzu package installed list -n tanzu-system-service-discovery

NAME          PACKAGE-NAME                   PACKAGE-VERSION        STATUS
external-dns  external-dns.tanzu.vmware.com  0.11.0+vmware.1-tkg.2  Reconcile succeeded

kubectl -n tanzu-system-service-discovery get all
NAME                               READY   STATUS    RESTARTS   AGE
pod/external-dns-77d947745-tcjz9   1/1     Running   0          63s

NAME                           READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/external-dns   1/1     1            1           63s

NAME                                     DESIRED   CURRENT   READY   AGE
replicaset.apps/external-dns-77d947745   1         1         1       63s

Install ExternalDNS Using Kubectl

Install the ExternalDNS package to synchronize exposed Kubernetes services and ingresses with DNS providers. The ExternalDNS package is validated for AWS (Route 53), Azure DNS, and RFC2136 (BIND).

Prerequisites

Adhere to the following prerequisites to install the ExternalDNS package.

Reference

Refer to the following topic as needed.

ExternalDNS Components, Configuration, Data Values.

Install ExternalDNS

Complete the following steps to install the ExternalDNS package.

List the available ExternalDNS versions in the repository.
```
kubectl get packages -n tkg-system
```
The most version is external-dns.tanzu.vmware.com.0.13.4+vmware.2-tkg.2.

Create the external-dns.yaml specification.

The following example is for Azure DNS. See ExternalDNS Components, Configuration, Data Values for others.

apiVersion: v1
kind: ServiceAccount
metadata:
  name: dns-sa
  namespace: tkg-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: dns-role-binding
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-admin
subjects:
  - kind: ServiceAccount
    name: dns-sa
    namespace: tkg-system
---
apiVersion: packaging.carvel.dev/v1alpha1
kind: PackageInstall
metadata:
  name: dns
  namespace: tkg-system
spec:
  serviceAccountName: dns-sa
  packageRef:
    refName: dns.tanzu.vmware.com
    versionSelection:
      constraints: 0.13.4+vmware.2-tkg.2
  values:
  - secretRef:
      name: dns-data-values
---
apiVersion: v1
kind: Secret
metadata:
  name: dns-data-values
  namespace: tkg-system
stringData:
  values.yml: |
    ---
    namespace: service-discovery
    dns:
      pspNames: "vmware-system-restricted"
      deployment:
        args:
        - --provider=azure
        - --source=service
        - --source=ingress
        - --source=contour-httpproxy #! configure external-dns to read Contour HTTPProxy resources
        - --domain-filter=my-zone.example.org #! zone where services are deployed
        - --azure-resource-group=my-resource-group #! Azure resource group
        volumeMounts:
        - name: azure-config-file
          mountPath: /etc/kubernetes
          readOnly: true
        #@overlay/replace
        volumes:
        - name: azure-config-file
          secret:
            secretName: azure-config-file

Customize the dns-data-values secret of the external-dns.yaml specification with appropriate values for your environment.

See External DNS Configuration Parameters for a full list of available parameters.
Install the ExternalDNS package.
```
kubectl apply -f external-dns.yaml
```
Verify ExternalDNS installation.
```
kubectl get all -n service-discovery
```