""" Primary interface for idempotent Lambda functions utility """ from __future__ import annotations import functools import logging import os import warnings from inspect import isclass from typing import TYPE_CHECKING, Any, Callable, cast from aws_lambda_powertools.middleware_factory import lambda_handler_decorator from aws_lambda_powertools.shared import constants from aws_lambda_powertools.shared.functions import strtobool from aws_lambda_powertools.shared.types import AnyCallableT from aws_lambda_powertools.utilities.idempotency.base import IdempotencyHandler from aws_lambda_powertools.utilities.idempotency.config import IdempotencyConfig from aws_lambda_powertools.utilities.idempotency.serialization.base import ( BaseIdempotencyModelSerializer, BaseIdempotencySerializer, ) if TYPE_CHECKING: from aws_lambda_powertools.utilities.idempotency.persistence.base import ( BasePersistenceLayer, ) from aws_lambda_powertools.utilities.typing import LambdaContext from aws_lambda_powertools.warnings import PowertoolsUserWarning logger = logging.getLogger(__name__) @lambda_handler_decorator def idempotent( handler: Callable[[Any, LambdaContext], Any], event: dict[str, Any], context: LambdaContext, persistence_store: BasePersistenceLayer, config: IdempotencyConfig | None = None, **kwargs, ) -> Any: """ Decorator to handle idempotency Parameters ---------- handler: Callable Lambda's handler event: dict Lambda's Event context: dict Lambda's Context persistence_store: BasePersistenceLayer Instance of BasePersistenceLayer to store data config: IdempotencyConfig Configuration Examples -------- **Processes Lambda's event in an idempotent manner** >>> from aws_lambda_powertools.utilities.idempotency import ( >>> idempotent, DynamoDBPersistenceLayer, IdempotencyConfig >>> ) >>> >>> idem_config=IdempotencyConfig(event_key_jmespath="body") >>> persistence_layer = DynamoDBPersistenceLayer(table_name="idempotency_store") >>> >>> @idempotent(config=idem_config, persistence_store=persistence_layer) >>> def handler(event, context): >>> return {"StatusCode": 200} """ # Skip idempotency controls when POWERTOOLS_IDEMPOTENCY_DISABLED has a truthy value # Raises a warning if not running in development mode if strtobool(os.getenv(constants.IDEMPOTENCY_DISABLED_ENV, "false")): warnings.warn( message="Disabling idempotency is intended for development environments only " "and should not be used in production.", category=PowertoolsUserWarning, stacklevel=2, ) return handler(event, context, **kwargs) config = config or IdempotencyConfig() config.register_lambda_context(context) args = event, context idempotency_handler = IdempotencyHandler( function=handler, function_payload=event, config=config, persistence_store=persistence_store, function_args=args, function_kwargs=kwargs, ) return idempotency_handler.handle() def idempotent_function( function: AnyCallableT | None = None, *, data_keyword_argument: str, persistence_store: BasePersistenceLayer, config: IdempotencyConfig | None = None, output_serializer: BaseIdempotencySerializer | type[BaseIdempotencyModelSerializer] | None = None, **kwargs: Any, ) -> Any: """ Decorator to handle idempotency of any function Parameters ---------- function: Callable Function to be decorated data_keyword_argument: str Keyword parameter name in function's signature that we should hash as idempotency key, e.g. "order" persistence_store: BasePersistenceLayer Instance of BasePersistenceLayer to store data config: IdempotencyConfig Configuration output_serializer: BaseIdempotencySerializer | type[BaseIdempotencyModelSerializer] | None Serializer to transform the data to and from a dictionary. If not supplied, no serialization is done via the NoOpSerializer. In case a serializer of type inheriting BaseIdempotencyModelSerializer is given, the serializer is derived from the function return type. Examples -------- **Processes an order in an idempotent manner** from aws_lambda_powertools.utilities.idempotency import ( idempotent_function, DynamoDBPersistenceLayer, IdempotencyConfig ) idem_config=IdempotencyConfig(event_key_jmespath="order_id") persistence_layer = DynamoDBPersistenceLayer(table_name="idempotency_store") @idempotent_function(data_keyword_argument="order", config=idem_config, persistence_store=persistence_layer) def process_order(customer_id: str, order: dict, **kwargs): return {"StatusCode": 200} """ if not function: return cast( AnyCallableT, functools.partial( idempotent_function, data_keyword_argument=data_keyword_argument, persistence_store=persistence_store, config=config, output_serializer=output_serializer, **kwargs, ), ) if isclass(output_serializer) and issubclass(output_serializer, BaseIdempotencyModelSerializer): # instantiate an instance of the serializer class output_serializer = output_serializer.instantiate(function.__annotations__.get("return", None)) config = config or IdempotencyConfig() @functools.wraps(function) def decorate(*args, **kwargs): # Skip idempotency controls when POWERTOOLS_IDEMPOTENCY_DISABLED has a truthy value # Raises a warning if not running in development mode if strtobool(os.getenv(constants.IDEMPOTENCY_DISABLED_ENV, "false")): warnings.warn( message="Disabling idempotency is intended for development environments only " "and should not be used in production.", category=PowertoolsUserWarning, stacklevel=2, ) return function(*args, **kwargs) if data_keyword_argument not in kwargs: raise RuntimeError( f"Unable to extract '{data_keyword_argument}' from keyword arguments." f" Ensure this exists in your function's signature as well as the caller used it as a keyword argument", ) payload = kwargs.get(data_keyword_argument) idempotency_handler = IdempotencyHandler( function=function, function_payload=payload, config=config, persistence_store=persistence_store, output_serializer=output_serializer, function_args=args, function_kwargs=kwargs, ) return idempotency_handler.handle() return cast(AnyCallableT, decorate)