From 1bb0db2dfabb5278933b53fded5cdc9cecaaa853 Mon Sep 17 00:00:00 2001
From: Aditya Nagesh <adityanagesh@microsoft.com>
Date: Wed, 11 Dec 2024 18:59:15 +0530
Subject: [PATCH] Transformer Logs: Save to file

Set transformer property 'enable_file_logging' to True
to save the transformer logs to file
---
 docs/run_test/runbook.rst |  7 +++++++
 lisa/schema.py            |  2 ++
 lisa/transformer.py       | 34 +++++++++++++++++++++++++++++++---
 3 files changed, 40 insertions(+), 3 deletions(-)

diff --git a/docs/run_test/runbook.rst b/docs/run_test/runbook.rst
index 669548543c..fcd0570f99 100644
--- a/docs/run_test/runbook.rst
+++ b/docs/run_test/runbook.rst
@@ -524,6 +524,13 @@ its value will be overwritten by the transformer. For example,
 ``to_list_image`` to ``image``. The original variable name must exist in
 the output variables of the transformer.
 
+enable_file_logging
+^^^^^^^^^^^^^^^^^^^
+
+type: bool, optional, default is False.
+
+When set to True, the transformer will log the output to a file.
+
 .. _combinator:
 
 combinator
diff --git a/lisa/schema.py b/lisa/schema.py
index 431dca0dd6..8f796173ff 100644
--- a/lisa/schema.py
+++ b/lisa/schema.py
@@ -187,6 +187,8 @@ class Transformer(TypedSchema, ExtendableSchemaMixin):
     rename: Dict[str, str] = field(default_factory=dict)
     # enable this transformer or not, only enabled transformers run actually.
     enabled: bool = True
+    # write logs to file. set to false by default
+    enable_file_logging: bool = False
     # decide when the transformer run. The init means run at very beginning
     # phase, which is before the combinator. The expanded means run after
     # combinator expanded variables.
diff --git a/lisa/transformer.py b/lisa/transformer.py
index 94a500eec1..b16826b45a 100644
--- a/lisa/transformer.py
+++ b/lisa/transformer.py
@@ -3,14 +3,23 @@
 
 import copy
 import functools
+from logging import FileHandler
+from pathlib import Path
 from typing import Any, Dict, List, Optional, Set
 
 from lisa import schema
 from lisa.environment import Environment
 from lisa.node import Node
 from lisa.parameter_parser.runbook import RunbookBuilder
-from lisa.util import InitializableMixin, LisaException, constants, subclasses
-from lisa.util.logger import get_logger
+from lisa.util import (
+    InitializableMixin,
+    LisaException,
+    constants,
+    get_datetime_path,
+    is_unittest,
+    subclasses,
+)
+from lisa.util.logger import create_file_handler, get_logger, remove_handler
 from lisa.variable import VariableEntry, merge_variables
 
 _get_init_logger = functools.partial(get_logger, "init", "transformer")
@@ -29,15 +38,18 @@ def __init__(
         self.prefix = runbook.prefix
         self.depends_on = runbook.depends_on
         self.rename = runbook.rename
+        self.enable_file_logging = runbook.enable_file_logging
 
         self._runbook_builder = runbook_builder
         self._log = get_logger("transformer", self.name)
 
+        if self.enable_file_logging:
+            self._log_handler = self._create_log_handler()
+
     def run(self) -> Dict[str, VariableEntry]:
         """
         Call by the transformer flow, don't override it in subclasses.
         """
-
         self._log.info("transformer is running.")
         variables = self._internal_run()
 
@@ -52,6 +64,10 @@ def run(self) -> Dict[str, VariableEntry]:
         self._log.debug(f"returned variables: {[x for x in results]}")
         if unmatched_rename:
             raise LisaException(f"unmatched rename variable: {unmatched_rename}")
+
+        if self.enable_file_logging and self._log_handler:
+            remove_handler(self._log_handler)
+            self._log_handler.close()
         return results
 
     @property
@@ -72,6 +88,18 @@ def _internal_run(self) -> Dict[str, Any]:
         """
         raise NotImplementedError()
 
+    def _create_log_path(self) -> Path:
+        path = constants.RUN_LOCAL_LOG_PATH / "transformers" / self.name
+        if not is_unittest():
+            path.mkdir(parents=True, exist_ok=True)
+        return path
+
+    def _create_log_handler(self) -> FileHandler:
+        self._log_path = self._create_log_path()
+        self._log_file = self._log_path / f"{get_datetime_path()}-{self.name}.log"
+        log_handler = create_file_handler(self._log_file, self._log)
+        return log_handler
+
 
 def _sort(transformers: List[schema.Transformer]) -> List[schema.Transformer]:
     visited: Set[str] = set()