refactor AZ script and helper func for proper AZ selection

... to account for regions with varied number of AZs and the eventuality
that AZ names could be something other than 1,2,3

dev-infrastructure/modules/aks-cluster-base.bicep

@@ -25,6 +25,10 @@ param dnsServiceIP string = '10.130.0.10'
 // Passed Params and Overrides
 param location string
 
+@description('List of Availability Zones to use for the AKS cluster')
+param locationAvailabilityZones array
+var locationHasAvailabilityZones = length(locationAvailabilityZones) > 0
+
 @description('Set to true to prevent resources from being pruned after 48 hours')
 param persist bool = false
 
@@ -58,13 +62,6 @@ var istioIngressGatewayIPAddressIPTagsArray = [
   }
 ]
 
-@description('List of Availability Zones for zone-redundant resources')
-param zoneRedundancyZones array = [
-  '1'
-  '2'
-  '3'
-]
-
 @maxLength(24)
 param aksKeyVaultName string
 
@@ -255,7 +252,7 @@ module istioIngressGatewayIPAddress '../modules/network/publicipaddress.bicep' =
     name: istioIngressGatewayIPAddressName
     ipTags: istioIngressGatewayIPAddressIPTagsArray
     location: location
-    zones: zoneRedundancyZones
+    zones: locationHasAvailabilityZones ? locationAvailabilityZones : null
     // Role Assignment needed for the public IP address to be used on the Load Balancer
     roleAssignmentProperties: {
       principalId: aksClusterUserDefinedManagedIdentity.properties.principalId
@@ -272,7 +269,7 @@ module aksClusterOutboundIPAddress '../modules/network/publicipaddress.bicep' =
     name: aksClusterOutboundIPAddressName
     ipTags: aksClusterOutboundIPAddressIPTagsArray
     location: location
-    zones: zoneRedundancyZones
+    zones: locationHasAvailabilityZones ? locationAvailabilityZones : null
     // Role Assignment needed for the public IP address to be used on the Load Balancer
     roleAssignmentProperties: {
       principalId: aksClusterUserDefinedManagedIdentity.properties.principalId
@@ -338,7 +335,7 @@ resource aksCluster 'Microsoft.ContainerService/managedClusters@2024-04-02-previ
         vnetSubnetID: aksNodeSubnet.id
         podSubnetID: aksPodSubnet.id
         maxPods: 100
-        availabilityZones: zoneRedundancyZones
+        availabilityZones: locationHasAvailabilityZones ? locationAvailabilityZones : null
         securityProfile: {
           enableSecureBoot: false
           enableVTPM: false
@@ -492,9 +489,7 @@ resource userAgentPools 'Microsoft.ContainerService/managedClusters/agentPools@2
       vnetSubnetID: aksNodeSubnet.id
       podSubnetID: aksPodSubnet.id
       maxPods: 225
-      availabilityZones: [
-        '${(i + 1)}'
-      ]
+      availabilityZones: locationHasAvailabilityZones ? [locationAvailabilityZones[i]] : null
       securityProfile: {
         enableSecureBoot: false
         enableVTPM: false

dev-infrastructure/scripts/list-az-regions.sh

@@ -7,12 +7,12 @@ az rest \
   --method get \
   --uri "/subscriptions/$(az account show --query id --output tsv)/locations?api-version=2024-11-01" \
   | jq -r '
-    # First, print items with availabilityZoneMappings set
-    "Regions with Availability Zones:",
-    (.value[] | select(.availabilityZoneMappings) | .name),
-    "",
-    # Then, print items without availabilityZoneMappings
-    "Regions without Availability Zones:",
-    (.value[] | select(.availabilityZoneMappings | not) | .name)
-  '
-
+    reduce .value[] as $item ({}; .[$item.name] = {
+      availabilityZones: (
+        if $item.availabilityZoneMappings then
+          $item.availabilityZoneMappings | map(.logicalZone)
+        else
+          []
+        end
+      )
+    }) | to_entries | sort_by(.key) | from_entries'