change logging

frontend/pkg/frontend/frontend.go

@@ -502,10 +502,12 @@ func (f *Frontend) ArmSubscriptionPut(writer http.ResponseWriter, request *http.
 	} else {
 		f.logger.Info(fmt.Sprintf("existing document found for subscription - will update document for subscription %s", subscriptionID))
 		doc.Subscription = &subscription
-	}
 
-	// Log differences
-	logSubscriptionDifferences(f.logger, doc.Subscription, &subscription)
+		messages := logSubscriptionDifferences(doc.Subscription, &subscription)
+		for _, message := range messages {
+			f.logger.Info(message)
+		}
+	}
 
 	err = f.dbClient.SetSubscriptionDoc(ctx, doc)
 	if err != nil {
@@ -645,39 +647,41 @@ func (f *Frontend) ArmDeploymentPreflight(writer http.ResponseWriter, request *h
 	arm.WriteDeploymentPreflightResponse(writer, preflightErrors)
 }
 
-func logSubscriptionDifferences(logger *slog.Logger, oldSub, newSub *arm.Subscription) {
+func logSubscriptionDifferences(oldSub, newSub *arm.Subscription) []string {
+	var messages []string
+
 	// Compare states
 	if oldSub.State != newSub.State {
-		logger.Info(fmt.Sprintf("Subscription state changed from %s to %s", oldSub.State, newSub.State))
+		messages = append(messages, fmt.Sprintf("Subscription state changed from %s to %s", oldSub.State, newSub.State))
 	}
 
 	if oldSub.Properties != nil && newSub.Properties != nil {
-		// Compare tenantId
 		if oldSub.Properties.TenantId != nil && newSub.Properties.TenantId != nil &&
 			*oldSub.Properties.TenantId != *newSub.Properties.TenantId {
-			logger.Info(fmt.Sprintf("Subscription tenantId changed from %s to %s", *oldSub.Properties.TenantId, *newSub.Properties.TenantId))
+			messages = append(messages, fmt.Sprintf("Subscription tenantId changed from %s to %s", *oldSub.Properties.TenantId, *newSub.Properties.TenantId))
 		}
 
-		// Compare registeredFeatures
 		if oldSub.Properties.RegisteredFeatures != nil && newSub.Properties.RegisteredFeatures != nil {
 			oldFeatures := featuresMap(oldSub.Properties.RegisteredFeatures)
 			newFeatures := featuresMap(newSub.Properties.RegisteredFeatures)
 
 			for featureName, oldState := range oldFeatures {
 				newState, exists := newFeatures[featureName]
 				if !exists {
-					logger.Info(fmt.Sprintf("Feature %s removed", featureName))
+					messages = append(messages, fmt.Sprintf("Feature %s removed", featureName))
 				} else if oldState != newState {
-					logger.Info(fmt.Sprintf("Feature %s state changed from %s to %s", featureName, oldState, newState))
+					messages = append(messages, fmt.Sprintf("Feature %s state changed from %s to %s", featureName, oldState, newState))
 				}
 			}
 			for featureName, newState := range newFeatures {
 				if _, exists := oldFeatures[featureName]; !exists {
-					logger.Info(fmt.Sprintf("Feature %s added with state %s", featureName, newState))
+					messages = append(messages, fmt.Sprintf("Feature %s added with state %s", featureName, newState))
 				}
 			}
 		}
 	}
+
+	return messages
 }
 
 func featuresMap(features *[]arm.Feature) map[string]string {