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<@ULVA73B9P> Regarding external logs; imagine I ha...
# ask-marvin
k
@Marvin Regarding external logs; imagine I have a python module named app from where I import some python objects:
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from app import func1, func2
Inside my prefect decorated tasks, I am making calls to func1, func2 and want their logs displayed in prefect ui but I do not want to decorate those functions as prefect task. Also, I do not want to pass the logger from prefect task to the functions; I want the default python logs of those functions to be captured by prefect. How do I do that?
m
To capture the default Python logs from your external functions (
func1
, 
func2
) and have them displayed in the Prefect UI, you can use the 
PREFECT_LOGGING_EXTRA_LOGGERS
setting. This setting allows Prefect to capture log statements from external libraries or modules used within your flows and tasks. Here's what you need to do: 1. Configure the Environment Variable: Set the 
PREFECT_LOGGING_EXTRA_LOGGERS
environment variable to include the module name from which you want to capture logs. For your case, if 
app
is the module name, you would set:
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bash
   export PREFECT_LOGGING_EXTRA_LOGGERS=app
2. Ensure Proper Logging in 
app
: Ensure that your 
func1
and 
func2
functions in the 
app
module use the standard Python logging module to log messages. 3. Run Prefect with the Configured Setting: When you run your Prefect flow, it will capture logs from the specified module and display them in the Prefect UI. For more details, you can refer to the Prefect Logging Documentation. If you need further assistance, feel free to ask.
k
hey @Marvin this does not seem to be working. Find my logging configuration in the app module below
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# Configure logging with module/file name and seconds in timestamp
import logging
logging.basicConfig(
    format="%(asctime)s - %(module)s - %(levelname)s - %(message)s",
    datefmt="%Y-%m-%d %H:%M:%S",
    level=logging.INFO,
)
m
To ensure that your external logs from the 
app
module are captured and displayed in the Prefect UI, make sure you follow these steps precisely: 1. Set the Environment Variable Correctly: Double-check that you have set the 
PREFECT_LOGGING_EXTRA_LOGGERS
environment variable to include the 
app
module. This setting should be applied before running your Prefect flow:
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bash
   export PREFECT_LOGGING_EXTRA_LOGGERS=app
2. Verify Logger Configuration: Ensure that the logger in your 
app
module is configured correctly and is using the standard Python logging library. Your configuration looks correct, but make sure the logging level and format are appropriate for capturing the logs you want. 3. Check Logger Propagation: Ensure that logger propagation is not disabled in your 
app
module. By default, Python loggers propagate messages to the root logger, which Prefect can capture. If propagation is disabled, Prefect won't see the logs. 4. Run Prefect with the Configured Logger: After setting the environment variable, run your Prefect flow. Prefect should now capture and display the logs from the 
app
module in the UI. If these steps do not resolve the issue, you might want to check your Prefect profile or environment to ensure no other settings are interfering with logging. For more detailed guidance, refer to the Prefect Logging Documentation.
Let's troubleshoot further. Here are a few things to check and try: 1. Ensure Propagation is Enabled: By default, loggers propagate messages to the root logger. However, if you've configured your logger elsewhere in 
app
to disable propagation, it won't reach Prefect. Make sure propagation is enabled:
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python
   logger = logging.getLogger('your_logger_name')
   logger.propagate = True
2. Check Logger Name: If you're using a named logger in your 
app
module, ensure that the name matches what you've specified in 
PREFECT_LOGGING_EXTRA_LOGGERS
. If using the root logger, the module name should suffice. 3. Explicitly Add Handlers: Prefect captures logs through handlers. Ensure that your logger has the appropriate handler set up. While 
basicConfig
should handle this, you might want to explicitly add a handler to ensure it's set correctly:
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python
   handler = logging.StreamHandler()
   handler.setLevel(<http://logging.INFO|logging.INFO>)
   formatter = logging.Formatter('%(asctime)s - %(module)s - %(levelname)s - %(message)s')
   handler.setFormatter(formatter)
   logger.addHandler(handler)
4. Test Outside of Prefect: Run a simple script outside of Prefect to ensure your logging configuration works as expected. This can help isolate if the issue is with the logging configuration or Prefect's capture. 5. Recheck Environment Variable: Confirm the environment variable is set in the same environment where Prefect is running. You might want to print it out in your flow to ensure it's correctly set. If none of these steps resolve the issue, you might want to explore Prefect's logging settings further or consult their logging documentation.
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