Add auditing to local syslog from PVC client

This ensures that any client command is logged by the local system.
Helps ensure Accounting for users of the CLI. Currently logs the full
command executed along with the $USER environment variable contents.

client-cli/pvc/pvc.py

@@ -28,8 +28,11 @@ import time
 import colorama
 import yaml
 import json
+import syslog
 import lxml.etree as etree
 
+from sys import argv
+
 from distutils.util import strtobool
 
 from functools import wraps
@@ -51,6 +54,22 @@ default_store_data = {"cfgfile": "/etc/pvc/pvcapid.yaml"}
 config = dict()
 
 
+#
+# Audit function
+#
+def audit():
+    args = argv
+    args[0] = "pvc"
+    syslog.openlog(facility=syslog.LOG_AUTH)
+    syslog.syslog(
+        'client audit: command "{}" by user "{}"'.format(
+            " ".join(args),
+            os.environ.get("USER", None),
+        )
+    )
+    syslog.closelog()
+
+
 #
 # Version function
 #
@@ -5702,6 +5721,8 @@ def cli(_cluster, _debug, _quiet, _unsafe, _colour):
             )
             echo("", err=True)
 
+    audit()
+
 
 #
 # Click command tree