live: revisit logging for checksum file creation

Add logging before calculating checksum to provide a hint to user on what is
going on while ogClient is still busy.

src/live/ogOperations.py

@@ -160,14 +160,15 @@ class OgLiveOperations:
 
     def _write_md5_file(self, path):
         if not os.path.exists(path):
-            raise OgError(f'Invalid image path {path} when computing md5 checksum')
+            raise OgError(f'Failed to calculate checksum, image file {path} does not exist')
+
         filename = path + ".full.sum"
         dig = self._compute_md5(path)
         try:
             with open(filename, 'w') as f:
                 f.write(dig)
         except:
-            logging.error(f'cannot write {filename}')
+            logging.error(f'Cannot write checksum {filename}')
             return -1
 
         return 0
@@ -470,12 +471,12 @@ class OgLiveOperations:
         self._ogbrowser_clear_logs()
         self._restartBrowser(self._url_log)
 
+        logging.info(f'Request to create image {name}.img at repository {repo}')
+
         if ogChangeRepo(repo, smb_user=self._smb_user, smb_pass=self._smb_pass) != 0:
             self._restartBrowser(self._url)
             raise OgError(f'Cannot change image repository to {repo}')
 
-        logging.info(f'Request to create image {name}.img at repository {repo}')
-
         if ogRest.terminated:
             return
 
@@ -560,6 +561,9 @@ class OgLiveOperations:
             else:
                 raise
 
+        logging.info(f'Writing checksum file {name}.img.full.sum...')
+        logging.info('*DO NOT REBOOT OR POWEROFF* the client during this time')
+
         if self._write_md5_file(f'/opt/opengnsys/images/{name}.img') == -1:
             raise OgError(f'Cannot write {name}.full.sum file')