Create an Azure Hosted Cluster on AKS

This document describes how to set up an Azure Hosted Cluster on an AKS management cluster with an ExternalDNS setup (starting in OCP 4.16).

If you already have an existing AKS cluster up and running, you can jump to the Setup ExternalDNS

Prerequisites

Obtain the az cli. See this for instructions.

To create an AKS cluster, first set up your constants

RG="aks-test"
LOCATION="eastus"
AKS_CLUSTER_NAME="test"

Log in to your Azure account through the CLI az login

Create an Azure Resource Group

az group create \
--name ${RG} \
--location ${LOCATION}

Create an AKS Cluster

az aks create \
--resource-group ${RG} \
--name ${AKS_CLUSTER_NAME} \
--node-count 3 \
--generate-ssh-keys \
--load-balancer-sku standard \
--os-sku AzureLinux \ 
--enable-fips-image

Finally, get your kubeconfig to your AKS cluster

az aks get-credentials \
--resource-group ${RG} \
--name ${AKS_CLUSTER_NAME} \
--overwrite-existing

Setup ExternalDNS

First setup some constants. The resource group needs to be different from the resource group your AKS cluster is in.

RG="example-hosted-cluster"
LOCATION="eastus"
DNS_ZONE_NAME="azure.myDNSName.com"
EXTERNAL_DNS_NEW_SP_NAME="ExternalDnsServicePrincipal"
CLUSTER_NAME=example-cluster
AZURE_CREDS=/Users/user/.azure/credentials
AZURE_BASE_DOMAIN=my.base.domain.com
PULL_SECRET=/Users/user/all-the-pull-secrets.json

Create an Azure resource group and your DNS zone, which will be used with ExternalDNS

az group create --name ${RG} --location ${LOCATION}
az network dns zone create --resource-group ${RG} --name ${DNS_ZONE_NAME}

Create a service principal for the DNS zone

DNS_SP=$(az ad sp create-for-rbac --name ${EXTERNAL_DNS_NEW_SP_NAME})
EXTERNAL_DNS_SP_APP_ID=$(echo "$DNS_SP" | jq -r '.appId')
EXTERNAL_DNS_SP_PASSWORD=$(echo "$DNS_SP" | jq -r '.password')

Assign the rights for the service principal

DNS_ID=$(az network dns zone show --name ${DNS_ZONE_NAME} --resource-group ${RG} --query "id" --output tsv)
az role assignment create --role "Reader" --assignee "${EXTERNAL_DNS_SP_APP_ID}" --scope "${DNS_ID}"
az role assignment create --role "Contributor" --assignee "${EXTERNAL_DNS_SP_APP_ID}" --scope "${DNS_ID}"

Create a configuration file for our service principal. Change the user path to the azure.json below as desired.

cat <<-EOF > /Users/user/azure.json
{
"tenantId": "$(az account show --query tenantId -o tsv)",
"subscriptionId": "$(az account show --query id -o tsv)",
"resourceGroup": "$RG",
"aadClientId": "$EXTERNAL_DNS_SP_APP_ID",
"aadClientSecret": "$EXTERNAL_DNS_SP_PASSWORD"
}
EOF

Create an ExternalDNS needed secret with the azure.json configuration file

kubectl delete secret/azure-config-file --namespace "default"
kubectl create secret generic azure-config-file --namespace "default" --from-file /Users/user/azure.json

Installing the HyperShift Operator

Make sure you add a record in your ExternalDNS provider from your @ records from your Azure DNS Zone.

Apply some CRDs that are missing

oc apply -f https://raw.githubusercontent.com/prometheus-operator/prometheus-operator/main/example/prometheus-operator-crd/monitoring.coreos.com_servicemonitors.yaml
oc apply -f https://raw.githubusercontent.com/prometheus-operator/prometheus-operator/main/example/prometheus-operator-crd/monitoring.coreos.com_prometheusrules.yaml
oc apply -f https://raw.githubusercontent.com/prometheus-operator/prometheus-operator/main/example/prometheus-operator-crd/monitoring.coreos.com_podmonitors.yaml
oc apply -f https://raw.githubusercontent.com/openshift/api/master/route/v1/zz_generated.crd-manifests/routes-Default.crd.yaml

Install the HyperShift operator

hypershift install \
--enable-conversion-webhook=false \
--external-dns-provider=azure \
--external-dns-credentials /Users/user/azure.json \
--pull-secret ${PULL_SECRET} \
--external-dns-domain-filter ${DNS_ZONE_NAME} \
--managed-service ARO-HCP

Create the Azure Hosted Cluster

Run the following command to create an Azure Hosted Cluster

hypershift create cluster azure \
--name $CLUSTER_NAME \
--azure-creds $AZURE_CREDS \
--location ${LOCATION} \
--node-pool-replicas 2 \
--base-domain $AZURE_BASE_DOMAIN \
--pull-secret $PULL_SECRET \
--generate-ssh \
--release-image quay.io/openshift-release-dev/ocp-release-nightly@sha256:b619707647800f7c382e7cb36e7b1026d82a576661274baffaf0585dd257fd1d \
--external-dns-domain ${DNS_ZONE_NAME} \
--resource-group-name ${RG} \
--annotations hypershift.openshift.io/pod-security-admission-label-override=baseline \
--annotations hypershift.openshift.io/certified-operators-catalog-image=registry.redhat.io/redhat/certified-operator-index@sha256:fc68a3445d274af8d3e7d27667ad3c1e085c228b46b7537beaad3d470257be3e \
--annotations hypershift.openshift.io/community-operators-catalog-image=registry.redhat.io/redhat/community-operator-index@sha256:4a2e1962688618b5d442342f3c7a65a18a2cb014c9e66bb3484c687cfb941b90 \
--annotations hypershift.openshift.io/redhat-marketplace-catalog-image=registry.redhat.io/redhat/redhat-marketplace-index@sha256:ed22b093d930cfbc52419d679114f86bd588263f8c4b3e6dfad86f7b8baf9844 \
--annotations hypershift.openshift.io/redhat-operators-catalog-image=registry.redhat.io/redhat/redhat-operator-index@sha256:59b14156a8af87c0c969037713fc49be7294401b10668583839ff2e9b49c18d6 \
--fips=true

Deleting the Azure Hosted Cluster

You can delete the cluster by using the following command:

hypershift destroy cluster azure \
--name $CLUSTER_NAME \
--azure-creds $AZURE_CREDS \
--resource-group-name ${RG}