Kubernetes Cluster Add-ons - GCP (4.3)

Kubernetes Add-ons

The following general Kubernetes add-ons should be added:

ExternalDNS

ExternalDNS is a Kubernetes add-on that configures public DNS servers with information about exposed Kubernetes services to make them discoverable.

To install ExternalDNS, follow these steps:

Add bitnami repository to the helm repository:

helm repo add bitnami https://charts.bitnami.com/bitnami

Update helm repository to get the latest software:
```
helm repo update
```

Create a file called external-dns-values.yaml and populate it with the following helm values:

gcp:
  zoneType: public
domainFilters:
  - <gke_domain_dns_name from terraform output>
policy: sync
provider: google
txtOwnerId: <gke_domain_zone_name from terraform output>
serviceAccount:
  annotations:
    iam.gke.io/gcp-service-account: <external_dns_service_account from terraform output>

Install the ExternalDNS helm chart:
```
helm install external-dns bitnami/external-dns -n uepe \
--version <helm chart version> -f external-dns-values.yaml
```
Where <helm chart version> is a compatible version listed in the Compatibility Matrix.

Ingress NGINX Controller

This is an optional add-on. Refer to the Introduction - GCP (4.1) chapter for additional information.

The Ingress NGINX Controller is an ingress controller for Kubernetes using NGINX as a reverse proxy and load balancer.

To install Ingress NGINX Controller, follow these steps:

Add ingress-nginx repository to the helm repository:

helm repo add ingress-nginx https://kubernetes.github.io/ingress-nginx

Update helm repository to get the latest software:
```
helm repo update
```

Create a file called ingress-nginx-values.yaml and populate it with the following helm values:

controller:
  scope:
    enabled: true
  admissionWebhooks:
    enabled: false
  metrics:
    enabled: false
    serviceMonitor:
      enabled: false
  ingressClassResource:
    name: nginx
    enabled: true
    default: false
    controllerValue: "k8s.io/ingress-nginx"
  watchIngressWithoutClass: false
  service:
    annotations:
      cloud.google.com/backend-config: '{"default": "nginx-controller-healthcheck-config"}'
      cloud.google.com/app-protocols: '{"http":"HTTP", "https":"HTTPS"}'  
    targetPorts:
      http: 80
      https: 443
    type: NodePort
  extraArgs:
    v: 1
serviceAccount:
  create: false

Install the ingress-nginx-controller helm chart:
```
helm install ingress-nginx ingress-nginx/ingress-nginx --version <helm chart version> -f ingress-nginx-values.yaml -n uepe
```
Where <helm chart version> is a compatible version listed in the Compatibility Matrix.

If you are running multiple installations on the cluster, in case the Nginx IngressClass resource is already installed, then you should set the following helm value to avoid hitting a resource already exists error:

controller.ingressClassResource.enabled=false

Executing helm list should show all add-ons added in this section:

NAME                        	NAMESPACE	REVISION	UPDATED                             	STATUS  	CHART                             	APP VERSION
external-dns                	uepe     	1       	2024-02-06 14:06:28.705309 +0800 +08	deployed	external-dns-6.31.5               	0.14.0     
ingress-nginx-controller        uepe     	1       	2024-02-22 11:44:54.18561 +0800 +08 	deployed	ingress-nginx-4.9.1               	1.9.6

This section is now complete. Now proceed to the Usage Engine Private Edition Preparations - GCP section.