making the tar file check use python when running locally, so can be run on windows machines

coordinator/ProcessorServer.py

@@ -3,6 +3,8 @@
 
 import datetime
 import logging
+import os
+import tarfile
 from string import Template
 from typing import List
 
@@ -43,21 +45,25 @@ def process_pre_job_server_download(input_args: dict):
 
         server_name: str = config['ServerName']
         full_file_path = f"{file_path}/{file_name}.tar.gz"
-        if server_name == "":
-            cmd_check_file = [f"test -f {full_file_path} && tar -tzf {full_file_path} > /dev/null"]
-            run_in_shell: bool = True
+
+        """
+        check the incoming met data tar exists and is a valid tar file (on either remote or local machine)
+        """
+        if server_name == "":  # means the file is local
+            data_is_ready = os.path.exists(full_file_path) and tarfile.is_tarfile(full_file_path)
         else:
             cmd_check_file = ["ssh", "-i", config['ServerKey'], "-o", "StrictHostKeyChecking=no", server_name,
                               f"test -f {full_file_path} && tar -tzf {full_file_path} >/dev/null"]
             run_in_shell: bool = False
 
-        description_short = 'subprocess_ssh'
-        description_long = f"Checking for existence of {file_path}/{file_name}.tar.gz"
+            description_short = 'subprocess_ssh'
+            description_long = f"Checking for existence of {file_path}/{file_name}.tar.gz"
 
-        status = subprocess_and_log(cmd_check_file, description_short, description_long, check = False,
-                                    shell = run_in_shell)
+            status = subprocess_and_log(cmd_check_file, description_short, description_long, check = False,
+                                        shell = run_in_shell)
+            data_is_ready = status.returncode > 0
 
-        if status.returncode > 0:
+        if not data_is_ready:
 
             # a time check in UTC. If it's late, raise warning, if very late, raise error
 
@@ -91,7 +97,7 @@ def process_pre_job_server_download(input_args: dict):
                 logger.info(message)
                 endScript(premature=True)
 
-        elif status.returncode == 0:
+        elif not data_is_ready:
             logger.info(f"Data is available for config {i+1} of {len(config_paths)}, calculation shall proceed")
 
     return True