def observability_init_middleware(handler: Callable,
event: Dict[str, Any],
context: LambdaContext,
logger: Logger,
metrics: Metrics,
log_structure: Dict[str, str] = None,
*args,
**kwargs) -> Any:
"""
An aws_lambda_powertools middleware function setting up standard logging
and metrics handling for lambda functions.
"""
if log_structure:
logger.structure_logs(append=True, **log_structure)
metrics.add_metadata(key='handler_name', value=handler.__module__)
try:
result = handler(event, context)
except Exception as err:
metrics.add_metric(name='function_failed', unit='Count', value=1)
logger.error({
'msg': 'Function failed',
'error': str(err),
'event': event
})
raise
else:
metrics.add_metric(name='function_succeeded', unit='Count', value=1)
return result
def test_logger_children_propagate_changes(stdout, service_name):
# GIVEN Loggers are initialized
# create child logger before parent to mimick
# importing logger from another module/file
# as loggers are created in global scope
child = Logger(stream=stdout, service=service_name, child=True)
parent = Logger(stream=stdout, service=service_name)
# WHEN a child Logger adds an additional key
child.structure_logs(append=True, customer_id="value")
# THEN child Logger changes should propagate to parent
# and subsequent log statements should have the latest value
parent.info("Hello parent")
child.info("Hello child")
parent_log, child_log = capture_multiple_logging_statements_output(stdout)
assert "customer_id" in parent_log
assert "customer_id" in child_log
assert child.parent.name == service_name
