Validate the direct downloaded template file format (QCOW2) if the template file exists (apache#10332)

* Validate the direct downloaded template file format (QCOW2) if the template file exists

* string format not required

Author: sureshanaparti

plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/storage/KVMStorageProcessor.java

@@ -2674,8 +2674,15 @@ public Answer handleDownloadTemplateToPrimaryStorage(DirectDownloadCommand cmd)
 
             template = storagePoolMgr.createPhysicalDiskFromDirectDownloadTemplate(tempFilePath, destTemplatePath, destPool, cmd.getFormat(), cmd.getWaitInMillSeconds());
 
-            String templatePath = template.getPath();
-            if (templatePath != null) {
+            String templatePath = null;
+            if (template != null) {
+                templatePath = template.getPath();
+            }
+            if (StringUtils.isEmpty(templatePath)) {
+                logger.warn("Skipped validation whether downloaded file is QCOW2 for template {}, due to downloaded template path is empty", template.getName());
+            } else if (!new File(templatePath).exists()) {
+                logger.warn("Skipped validation whether downloaded file is QCOW2 for template {}, due to downloaded template path is not valid: {}", template.getName(), templatePath);
+            } else {
                 try {
                     Qcow2Inspector.validateQcow2File(templatePath);
                 } catch (RuntimeException e) {