powershell - ouput as json

This patch enables the run_cmdlet method in lisa/tools/powershell.py to output the result as JSON when the output_json parameter is set to True.

Getting Powershell output as JSON is beneficial because it allows for easier parsing and processing of the output data.

lisa/tools/powershell.py

@@ -3,6 +3,7 @@
 
 import base64
 from typing import Any
+import json
 from xml.etree import ElementTree
 
 from lisa.executable import Tool
@@ -48,14 +49,17 @@ def run_cmdlet_async(
     def run_cmdlet(
         self,
         cmdlet: str,
+        output_json: bool = False,
         force_run: bool = False,
         sudo: bool = False,
         fail_on_error: bool = True,
         timeout: int = 600,
         # Powershell error log is the xml format, it needs extra decoding. But
         # for long running script, it needs to look real time results.
         no_debug_log: bool = True,
-    ) -> str:
+    ) -> Any:
+        if output_json:
+            cmdlet = f"{cmdlet} | ConvertTo-Json"
         process = self.run_cmdlet_async(
             cmdlet=cmdlet, force_run=force_run, sudo=sudo, no_debug_log=no_debug_log
         )
@@ -68,7 +72,8 @@ def run_cmdlet(
             # if stdout is output already, it doesn't need to output again.
             no_debug_log=not no_debug_log,
         )
-
+        if output_json and result.stdout:
+            return json.loads(result.stdout)
         return result.stdout
 
     def wait_result(