fix: preserve existing AZURE_LOCATION in randomize scripts

Prevent location conflicts when re-running azd provision by checking
if AZURE_LOCATION is already set before randomizing. This fixes the
issue where lab users would encounter errors on retry because the
location changed between provision attempts.

- Add existence check using 'azd env get-value AZURE_LOCATION'
- Only randomize location if not already set or empty
- Apply fix to both bash and PowerShell versions
- Tested with multiple scenarios (existing, empty, persistence)

Author: dbarkol

scripts/randomize-region.ps1

@@ -2,10 +2,18 @@
 # Run this script before 'azd provision' or 'azd up' to use a random region
 # without being prompted. Otherwise, azd will prompt you to select a region.
 
-$regions = @("westus2", "westus3", "eastus2", "northcentralus")
-$selectedRegion = Get-Random -InputObject $regions
+# Check if AZURE_LOCATION is already set
+$existingLocation = azd env get-value AZURE_LOCATION 2>$null
 
-Write-Host "🎲 Randomly selected region: $selectedRegion" -ForegroundColor Green
-azd env set AZURE_LOCATION $selectedRegion
-Write-Host "✅ Region set. Run 'azd provision' to deploy without being prompted." -ForegroundColor Green
-Write-Host "   To change: azd env set AZURE_LOCATION <region>" -ForegroundColor Gray
+if ($existingLocation) {
+    Write-Host "ℹ️  AZURE_LOCATION is already set to: $existingLocation" -ForegroundColor Cyan
+    Write-Host "   Keeping existing location. To change, run: azd env set AZURE_LOCATION <region>" -ForegroundColor Gray
+} else {
+    $regions = @("westus2", "westus3", "eastus2", "northcentralus")
+    $selectedRegion = Get-Random -InputObject $regions
+
+    Write-Host "🎲 Randomly selected region: $selectedRegion" -ForegroundColor Green
+    azd env set AZURE_LOCATION $selectedRegion
+    Write-Host "✅ Region set. Run 'azd provision' to deploy without being prompted." -ForegroundColor Green
+    Write-Host "   To change: azd env set AZURE_LOCATION <region>" -ForegroundColor Gray
+}

scripts/randomize-region.sh

@@ -3,11 +3,19 @@
 # Run this script before 'azd provision' or 'azd up' to use a random region
 # without being prompted. Otherwise, azd will prompt you to select a region.
 
-REGIONS=("westus2" "westus3" "eastus2", "northcentralus")
-RANDOM_INDEX=$((RANDOM % 3))
-SELECTED_REGION="${REGIONS[$RANDOM_INDEX]}"
+# Check if AZURE_LOCATION is already set
+EXISTING_LOCATION=$(azd env get-value AZURE_LOCATION 2>/dev/null)
 
-echo "🎲 Randomly selected region: $SELECTED_REGION"
-azd env set AZURE_LOCATION "$SELECTED_REGION"
-echo "✅ Region set. Run 'azd provision' to deploy without being prompted."
-echo "   To change: azd env set AZURE_LOCATION <region>"
+if [ -n "$EXISTING_LOCATION" ]; then
+    echo "ℹ️  AZURE_LOCATION is already set to: $EXISTING_LOCATION"
+    echo "   Keeping existing location. To change, run: azd env set AZURE_LOCATION <region>"
+else
+    REGIONS=("westus2" "westus3" "eastus2", "northcentralus")
+    RANDOM_INDEX=$((RANDOM % 3))
+    SELECTED_REGION="${REGIONS[$RANDOM_INDEX]}"
+
+    echo "🎲 Randomly selected region: $SELECTED_REGION"
+    azd env set AZURE_LOCATION "$SELECTED_REGION"
+    echo "✅ Region set. Run 'azd provision' to deploy without being prompted."
+    echo "   To change: azd env set AZURE_LOCATION <region>"
+fi