Improve UDF logging options (#88)

* Update docs

* feat(functions): refactor logging configuration for UDF applications

- Add log_file, log_format, and log_level parameters to Application class
- Move logging configuration from main() to Application.__init__() via _configure_logging()
- Add external_function.log_file and external_function.log_format config options
- Update Application docstring to document all parameters including logging
- Refactor Timer.finish() to return metrics dict instead of logging directly
- Configure uvicorn logging to use same log file when specified

This refactoring centralizes logging configuration and allows for more flexible
UDF application logging through configuration parameters.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

* Add disable_metrics option to external functions

- Add external_function.disable_metrics configuration option (default: False)
- Add disable_metrics parameter to Application class constructor
- Update Application to create logger-specific instances with unique names
- Add --disable-metrics command-line argument to main function
- Conditionally log metrics based on disable_metrics flag
- Support configuration via environment variable SINGLESTOREDB_EXT_FUNC_DISABLE_METRICS

This allows users to disable the logging of function call metrics when needed,
while maintaining backward compatibility with existing behavior.

* refactor(functions): remove log_format config, add app_name parameter

- Remove external_function.log_format configuration option and --log-format CLI flag
- Standardize on JSON formatted logging for all external function applications
- Add external_function.app_name configuration option with --app-name CLI flag
- Change Application class constructor parameter from 'name=' to 'app_name=' for consistency
- Update logging configuration to use JSON formatter for both console and file output
- Improve structured logging with additional context fields (app_name, request_id, etc.)

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

* Propagate log level to UDF app

* feat: add get_uvicorn_log_config method to Application class

- Move uvicorn log config creation from main() into a reusable method
- Allow external users to match the Application's logging format
- Simplify main() by using the new method
- Uses the same JSON formatter and settings as Application's internal logging

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

---------

Co-authored-by: Claude <noreply@anthropic.com>

Author: kesmit13

singlestoredb/apps/_python_udfs.py

@@ -47,7 +47,12 @@ async def run_udf_app(
     udf_suffix = ''
     if app_config.running_interactively:
         udf_suffix = '_test'
-    app = Application(url=base_url, app_mode='managed', name_suffix=udf_suffix)
+    app = Application(
+        url=base_url,
+        app_mode='managed',
+        name_suffix=udf_suffix,
+        log_level=log_level,
+    )
 
     if not app.endpoints:
         raise ValueError('You must define at least one function.')
@@ -60,7 +65,7 @@ async def run_udf_app(
         app,
         host='0.0.0.0',
         port=app_config.listen_port,
-        log_level=log_level,
+        log_config=app.get_uvicorn_log_config(),
     )
 
     # Register the functions only if the app is running interactively.

singlestoredb/config.py

@@ -407,6 +407,12 @@
     environ=['SINGLESTOREDB_EXT_FUNC_LOG_LEVEL'],
 )
 
+register_option(
+    'external_function.log_file', 'string', check_str, None,
+    'File path to write logs to instead of console.',
+    environ=['SINGLESTOREDB_EXT_FUNC_LOG_FILE'],
+)
+
 register_option(
     'external_function.name_prefix', 'string', check_str, '',
     'Prefix to add to external function names.',
@@ -450,6 +456,18 @@
     environ=['SINGLESTOREDB_EXT_FUNC_TIMEOUT'],
 )
 
+register_option(
+    'external_function.disable_metrics', 'bool', check_bool, False,
+    'Disable logging of function call metrics.',
+    environ=['SINGLESTOREDB_EXT_FUNC_DISABLE_METRICS'],
+)
+
+register_option(
+    'external_function.app_name', 'string', check_str, None,
+    'Name for the external function application instance.',
+    environ=['SINGLESTOREDB_EXT_FUNC_APP_NAME'],
+)
+
 #
 # Debugging options
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