Refactor VM credential handling to use conditional expressions for default values

Author: Ayaz-Microsoft

docs/DeploymentGuide.md

@@ -202,7 +202,7 @@ Copy the contents from the production configuration file to your main parameters
 
 > **Note:** This section only applies if you selected **Production** deployment type in section 3.1. VMs are not deployed in the default Development/Testing configuration.
 
-By default, random GUIDs are generated for VM credentials. To set custom credentials:
+By default, hard-coded fallback values are used for VM credentials (`JumpboxAdminUser` / `JumpboxAdminP@ssw0rd1234!`). To set custom credentials:
 
 ```shell
 azd env set AZURE_ENV_JUMPBOX_ADMIN_USERNAME <your-username>

infra/main.bicep

@@ -637,9 +637,9 @@ module virtualMachine 'br/public:avm/res/compute/virtual-machine:0.20.0' = if (e
     enableTelemetry: enableTelemetry
     computerName: take(virtualMachineResourceName, 15)
     osType: 'Windows'
-    vmSize: vmSize ?? 'Standard_D2s_v5'
-    adminUsername: vmAdminUsername ?? 'JumpboxAdminUser'
-    adminPassword: vmAdminPassword ?? 'JumpboxAdminP@ssw0rd1234!'
+    vmSize: !empty(vmSize) ? vmSize : 'Standard_D2s_v5'
+    adminUsername: !empty(vmAdminUsername) ? vmAdminUsername : 'JumpboxAdminUser'
+    adminPassword: !empty(vmAdminPassword) ? vmAdminPassword : 'JumpboxAdminP@ssw0rd1234!'
     managedIdentities: {
       systemAssigned: true
     }

infra/main.json

@@ -16625,13 +16625,13 @@
             "value": "Windows"
           },
           "vmSize": {
-            "value": "[coalesce(parameters('vmSize'), 'Standard_D2s_v5')]"
+            "value": "[if(not(empty(parameters('vmSize'))), parameters('vmSize'), 'Standard_D2s_v5')]"
           },
           "adminUsername": {
-            "value": "[coalesce(parameters('vmAdminUsername'), 'JumpboxAdminUser')]"
+            "value": "[if(not(empty(parameters('vmAdminUsername'))), parameters('vmAdminUsername'), 'JumpboxAdminUser')]"
           },
           "adminPassword": {
-            "value": "[coalesce(parameters('vmAdminPassword'), 'JumpboxAdminP@ssw0rd1234!')]"
+            "value": "[if(not(empty(parameters('vmAdminPassword'))), parameters('vmAdminPassword'), 'JumpboxAdminP@ssw0rd1234!')]"
           },
           "managedIdentities": {
             "value": {

infra/main_custom.bicep

@@ -566,9 +566,9 @@ module virtualMachine 'br/public:avm/res/compute/virtual-machine:0.20.0' = if (e
     enableTelemetry: enableTelemetry
     computerName: take(virtualMachineResourceName, 15)
     osType: 'Windows'
-    vmSize: vmSize ?? 'Standard_D2s_v5'
-    adminUsername: vmAdminUsername ?? 'JumpboxAdminUser'
-    adminPassword: vmAdminPassword ?? 'JumpboxAdminP@ssw0rd1234!'
+    vmSize: !empty(vmSize) ? vmSize : 'Standard_D2s_v5'
+    adminUsername: !empty(vmAdminUsername) ? vmAdminUsername : 'JumpboxAdminUser'
+    adminPassword: !empty(vmAdminPassword) ? vmAdminPassword : 'JumpboxAdminP@ssw0rd1234!'
     managedIdentities: {
       systemAssigned: true
     }