From 4e887594382bf4bbe10ae78b225a2074d0c6a167 Mon Sep 17 00:00:00 2001
From: "Vighneshwar (Vigh) Madas"
 <94487632+iamvighnesh@users.noreply.github.com>
Date: Thu, 16 Nov 2023 12:28:11 +0000
Subject: [PATCH] Set default osDiskSizeGB based on OS Type (#661)

Co-authored-by: Paul Lewis <pjlewisuk@users.noreply.github.com>
---
 bicep/aksagentpool.bicep | 7 +++++--
 bicep/main.bicep         | 5 ++++-
 helper/src/config.json   | 2 +-
 3 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/bicep/aksagentpool.bicep b/bicep/aksagentpool.bicep
index d31a2b420..493a668a1 100644
--- a/bicep/aksagentpool.bicep
+++ b/bicep/aksagentpool.bicep
@@ -60,7 +60,10 @@ var spotProperties = {
   spotMaxPrice: -1
 }
 
-resource aks 'Microsoft.ContainerService/managedClusters@2023-08-02-preview' existing = {
+// Default OS Disk Size in GB for Linux is 30, for Windows is 100
+var defaultOsDiskSizeGB = osType == 'Linux' ? 30 : 100
+
+resource aks 'Microsoft.ContainerService/managedClusters@2023-07-02-preview' existing = {
   name: AksName
 }
 
@@ -77,7 +80,7 @@ resource userNodepool 'Microsoft.ContainerService/managedClusters/agentPools@202
       availabilityZones: !empty(availabilityZones) ? availabilityZones : null
       osDiskType: osDiskType
       osSKU: osSKU
-      osDiskSizeGB: osDiskSizeGB
+      osDiskSizeGB: osDiskSizeGB == 0 ? defaultOsDiskSizeGB : osDiskSizeGB
       osType: osType
       maxPods: maxPods
       type: 'VirtualMachineScaleSets'
diff --git a/bicep/main.bicep b/bicep/main.bicep
index e0f4d1eef..28ec1272d 100644
--- a/bicep/main.bicep
+++ b/bicep/main.bicep
@@ -1382,6 +1382,9 @@ param osSKU string = 'Ubuntu'
 
 var poolName = osType == 'Linux' ? nodePoolName : take(nodePoolName, 6)
 
+// Default OS Disk Size in GB for Linux is 30, for Windows is 100
+var defaultOsDiskSizeGB = osType == 'Linux' ? 30 : 100
+
 module userNodePool '../bicep/aksagentpool.bicep' = if (!JustUseSystemPool){
   name: take('${deployment().name}-userNodePool',64)
   params: {
@@ -1397,7 +1400,7 @@ module userNodePool '../bicep/aksagentpool.bicep' = if (!JustUseSystemPool){
     osType: osType
     osSKU: osSKU
     enableNodePublicIP: enableNodePublicIP
-    osDiskSizeGB: osDiskSizeGB
+    osDiskSizeGB: osDiskSizeGB == 0 ? defaultOsDiskSizeGB : osDiskSizeGB
     availabilityZones: availabilityZones
     spotInstance: nodePoolSpot
   }
diff --git a/helper/src/config.json b/helper/src/config.json
index 55672feb1..fb712434a 100644
--- a/helper/src/config.json
+++ b/helper/src/config.json
@@ -50,7 +50,7 @@
             "maxCount": 20,
             "computeType": "gp",
             "vmSize": "Standard_DS3_v2",
-            "osDiskSizeGB": 0,
+            "osDiskSizeGB": 30,
             "osDiskType": "Ephemeral",
             "enable_aad": true,
             "AksDisableLocalAccounts": false,