Move rename_ping_staistics_file_to_checked function to common os module

This patch moves function `rename_ping_staistics_file_to_checked` to the
`tobiko.common._os` module and renames it to the `truncate_file`.
Additionally it adds helper function to get name of the truncated file.
The reason for those changes is that the same functions will be used in
the background iperf tests also.

Related: #TOBIKO-128
Change-Id: I14bbfc51f37323a106bd5e0e4fbf6d7145f716d8

tobiko/__init__.py

@@ -107,6 +107,8 @@ interworker_synched = _lockutils.interworker_synched
 
 makedirs = _os.makedirs
 open_output_file = _os.open_output_file
+get_truncated_filename = _os.get_truncated_filename
+truncate_logfile = _os.truncate_logfile
 
 runs_operation = _operation.runs_operation
 before_operation = _operation.before_operation

tobiko/common/_os.py

@@ -16,6 +16,7 @@ from __future__ import absolute_import
 import contextlib
 import os
 import tempfile
+import time
 
 from oslo_log import log
 
@@ -57,3 +58,13 @@ def open_output_file(filename, mode='w', temp_dir=None, text=False):
         with _exception.exc_info():
             if os.path.isfile(temp_filename):
                 os.remove(temp_filename)
+
+
+def get_truncated_filename(filepath: str) -> str:
+    check_time = time.strftime("%Y_%m_%d-%H-%M-%S")
+    return f'{filepath}_checked_{check_time}'
+
+
+def truncate_logfile(filepath):
+    """append _checked to a ping statistics file once finished it's check"""
+    os.rename(filepath, get_truncated_filename(filepath))

tobiko/shell/ping/_ping.py

@@ -466,12 +466,6 @@ def get_vm_ping_log_files(glob_ping_log_pattern='tobiko_ping_results/ping_'
         yield vm_ping_log_filename
 
 
-def rename_ping_staistics_file_to_checked(filepath):
-    """append _checked to a ping statistics file once finished it's check"""
-    check_time = time.strftime("%Y_%m_%d-%H-%M-%S")
-    os.rename(filepath, f'{filepath}_checked_{check_time}')
-
-
 def check_ping_statistics(failure_limit=10):
     """Gets a list of ping_vm_log files and
     iterates their lines, checks if max ping
@@ -495,7 +489,7 @@ def check_ping_statistics(failure_limit=10):
             else:
                 LOG.info(f'no failures in ping log file: {filename}')
 
-            rename_ping_staistics_file_to_checked(filename)
+            tobiko.truncate_logfile(filename)
 
             if ping_failures_len >= failure_limit:
                 tobiko.fail(f'{ping_failures_len} pings failure found '
@@ -505,5 +499,5 @@ def check_ping_statistics(failure_limit=10):
 
 def skip_check_ping_statistics():
     for filename in list(get_vm_ping_log_files()):
-        rename_ping_staistics_file_to_checked(filename)
+        tobiko.truncate_logfile(filename)
         LOG.info(f'skipping ping failures in ping log file: {filename}')