Change_log_level (#187)

added a sample showing how change workflow task failure log levels to error

Author: GSmithApps

README.md

@@ -41,6 +41,7 @@ Some examples require extra dependencies. See each sample's directory for specif
   * [hello_async_activity_completion](hello/hello_async_activity_completion.py) - Complete an activity outside of the
     function that was called.
   * [hello_cancellation](hello/hello_cancellation.py) - Manually react to cancellation inside workflows and activities.
+  * [hello_change_log_level](hello/hello_change_log_level.py) - Change the level of workflow task failure from WARN to ERROR.
   * [hello_child_workflow](hello/hello_child_workflow.py) - Execute a child workflow from a workflow.
   * [hello_continue_as_new](hello/hello_continue_as_new.py) - Use continue as new to restart a workflow.
   * [hello_cron](hello/hello_cron.py) - Execute a workflow once a minute.

hello/README.md

@@ -28,6 +28,7 @@ Replace `hello_activity.py` in the command with any other example filename to ru
 * [hello_async_activity_completion](hello_async_activity_completion.py) - Complete an activity outside of the function
   that was called.
 * [hello_cancellation](hello_cancellation.py) - Manually react to cancellation inside workflows and activities.
+* [hello_change_log_level](hello_change_log_level.py) - Change the level of workflow task failure from WARN to ERROR.
 * [hello_child_workflow](hello_child_workflow.py) - Execute a child workflow from a workflow.
 * [hello_continue_as_new](hello_continue_as_new.py) - Use continue as new to restart a workflow.
 * [hello_cron](hello_cron.py) - Execute a workflow once a minute.

hello/hello_change_log_level.py

@@ -0,0 +1,67 @@
+"""
+Changes the log level of workflow task failures from WARN to ERROR.
+
+Note that the __temporal_error_identifier attribute was added in
+version 1.13.0 of the Python SDK.
+"""
+
+import asyncio
+import logging
+import sys
+
+from temporalio import workflow
+from temporalio.client import Client
+from temporalio.worker import Worker
+
+# --- Begin logging set‑up ----------------------------------------------------------
+logging.basicConfig(
+    stream=sys.stdout,
+    level=logging.INFO,
+    format="%(asctime)s  %(levelname)-8s  %(name)s  %(message)s",
+)
+
+
+class CustomLogFilter(logging.Filter):
+    def filter(self, record: logging.LogRecord) -> bool:
+        # Note that the __temporal_error_identifier attribute was added in
+        # version 1.13.0 of the Python SDK.
+        if (
+            hasattr(record, "__temporal_error_identifier")
+            and getattr(record, "__temporal_error_identifier") == "WorkflowTaskFailure"
+        ):
+            record.levelno = logging.ERROR
+            record.levelname = logging.getLevelName(logging.ERROR)
+        return True
+
+
+for h in logging.getLogger().handlers:
+    h.addFilter(CustomLogFilter())
+# --- End logging set‑up ----------------------------------------------------------
+
+
+LOG_MESSAGE = "This error is an experiment to check the log level"
+
+
+@workflow.defn
+class GreetingWorkflow:
+    @workflow.run
+    async def run(self):
+        raise RuntimeError(LOG_MESSAGE)
+
+
+async def main():
+    client = await Client.connect("localhost:7233")
+    async with Worker(
+        client,
+        task_queue="hello-change-log-level-task-queue",
+        workflows=[GreetingWorkflow],
+    ):
+        await client.execute_workflow(
+            GreetingWorkflow.run,
+            id="hello-change-log-level-workflow-id",
+            task_queue="hello-change-log-level-task-queue",
+        )
+
+
+if __name__ == "__main__":
+    asyncio.run(main())

tests/hello/hello_change_log_level_test.py

@@ -0,0 +1,43 @@
+import asyncio
+import io
+import logging
+import uuid
+
+from temporalio.client import Client
+from temporalio.worker import Worker
+
+from hello.hello_change_log_level import LOG_MESSAGE, GreetingWorkflow
+
+
+async def test_workflow_with_log_capture(client: Client):
+
+    log_stream = io.StringIO()
+    handler = logging.StreamHandler(log_stream)
+    handler.setLevel(logging.ERROR)
+
+    logger = logging.getLogger()
+    logger.addHandler(handler)
+    logger.setLevel(logging.DEBUG)
+
+    task_queue = f"tq-{uuid.uuid4()}"
+
+    async with Worker(
+        client,
+        task_queue=task_queue,
+        workflows=[GreetingWorkflow],
+    ):
+        handle = await client.start_workflow(
+            GreetingWorkflow.run,
+            id=f"wf-{uuid.uuid4()}",
+            task_queue=task_queue,
+        )
+        await asyncio.sleep(
+            0.2
+        )  # small wait to ensure the workflow has started, failed, and logged
+        await handle.terminate()
+
+    logger.removeHandler(handler)
+    handler.flush()
+
+    logs = log_stream.getvalue()
+    assert LOG_MESSAGE in logs