fix(idempotency): POWERTOOLS_IDEMPOTENCY_DISABLED should respect truthy values (#4391)

Co-authored-by: Leandro Damascena <[email protected]>

Author: stevenhoelscher

aws_lambda_powertools/utilities/idempotency/idempotency.py

@@ -5,11 +5,13 @@
 import functools
 import logging
 import os
+import warnings
 from inspect import isclass
 from typing import Any, Callable, Dict, Optional, Type, Union, 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
@@ -21,6 +23,7 @@
     BaseIdempotencySerializer,
 )
 from aws_lambda_powertools.utilities.typing import LambdaContext
+from aws_lambda_powertools.warnings import PowertoolsUserWarning
 
 logger = logging.getLogger(__name__)
 
@@ -66,7 +69,15 @@ def idempotent(
         >>>     return {"StatusCode": 200}
     """
 
-    if os.getenv(constants.IDEMPOTENCY_DISABLED_ENV):
+    # 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()
@@ -150,7 +161,15 @@ def process_order(customer_id: str, order: dict, **kwargs):
 
     @functools.wraps(function)
     def decorate(*args, **kwargs):
-        if os.getenv(constants.IDEMPOTENCY_DISABLED_ENV):
+        # 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:

aws_lambda_powertools/warnings/__init__.py

@@ -0,0 +1,23 @@
+"""Shared warnings that don't belong to a single utility"""
+
+
+class PowertoolsUserWarning(UserWarning):
+    """
+    This class provides a custom Warning tailored for better clarity when certain situations occur.
+
+     Examples:
+    - Using development-only features in production environment.
+    - Potential performance or security issues due to misconfiguration.
+
+    Parameters
+    ----------
+    message: str
+         The warning message to be displayed.
+    """
+
+    def __init__(self, message):
+        self.message = message
+        super().__init__(message)
+
+    def __str__(self):
+        return self.message

tests/functional/idempotency/test_idempotency.py

@@ -51,6 +51,7 @@
     PydanticSerializer,
 )
 from aws_lambda_powertools.utilities.validation import envelopes, validator
+from aws_lambda_powertools.warnings import PowertoolsUserWarning
 from tests.functional.idempotency.utils import (
     build_idempotency_put_item_response_stub,
     build_idempotency_put_item_stub,
@@ -1667,13 +1668,20 @@ def dummy(payload):
     dummy(payload=data_two)
 
 
-def test_idempotency_disabled_envvar(monkeypatch, lambda_context, persistence_store: DynamoDBPersistenceLayer):
+@pytest.mark.parametrize("idempotency_disabled_value", ["1", "y", "yes", "t", "true", "on"])
+def test_idempotency_enabled_envvar_in_dev_environment(
+    monkeypatch,
+    lambda_context,
+    persistence_store: DynamoDBPersistenceLayer,
+    idempotency_disabled_value,
+):
     # Scenario to validate no requests sent to dynamodb table when 'POWERTOOLS_IDEMPOTENCY_DISABLED' is set
     mock_event = {"data": "value"}
 
     persistence_store.client = MagicMock()
 
-    monkeypatch.setenv("POWERTOOLS_IDEMPOTENCY_DISABLED", "1")
+    monkeypatch.setenv("POWERTOOLS_IDEMPOTENCY_DISABLED", str(idempotency_disabled_value))
+    monkeypatch.setenv("POWERTOOLS_DEV", "true")
 
     @idempotent_function(data_keyword_argument="data", persistence_store=persistence_store)
     def dummy(data):
@@ -1689,6 +1697,63 @@ def dummy_handler(event, context):
     assert len(persistence_store.client.method_calls) == 0
 
 
+@pytest.mark.parametrize("idempotency_disabled_value", ["1", "y", "yes", "t", "true", "on"])
+def test_idempotency_enabled_envvar_in_non_dev_environment(
+    monkeypatch,
+    lambda_context,
+    persistence_store: DynamoDBPersistenceLayer,
+    idempotency_disabled_value,
+):
+    # Scenario to validate no requests sent to dynamodb table when 'POWERTOOLS_IDEMPOTENCY_DISABLED' is set
+    mock_event = {"data": "value"}
+
+    persistence_store.client = MagicMock()
+
+    monkeypatch.setenv("POWERTOOLS_IDEMPOTENCY_DISABLED", str(idempotency_disabled_value))
+
+    @idempotent_function(data_keyword_argument="data", persistence_store=persistence_store)
+    def dummy(data):
+        return {"message": "hello"}
+
+    @idempotent(persistence_store=persistence_store)
+    def dummy_handler(event, context):
+        return {"message": "hi"}
+
+    with pytest.warns(PowertoolsUserWarning, match="Disabling idempotency is intended for development environments*"):
+        dummy(data=mock_event)
+        dummy_handler(mock_event, lambda_context)
+
+        assert len(persistence_store.client.method_calls) == 0
+
+
+@pytest.mark.parametrize("idempotency_disabled_value", ["0", "n", "no", "f", "false", "off"])
+def test_idempotency_disabled_envvar(
+    monkeypatch,
+    lambda_context,
+    persistence_store: DynamoDBPersistenceLayer,
+    idempotency_disabled_value,
+):
+    # Scenario to validate no requests sent to dynamodb table when 'POWERTOOLS_IDEMPOTENCY_DISABLED' is false
+    mock_event = {"data": "value"}
+
+    persistence_store.client = MagicMock()
+
+    monkeypatch.setenv("POWERTOOLS_IDEMPOTENCY_DISABLED", str(idempotency_disabled_value))
+
+    @idempotent_function(data_keyword_argument="data", persistence_store=persistence_store)
+    def dummy(data):
+        return {"message": "hello"}
+
+    @idempotent(persistence_store=persistence_store)
+    def dummy_handler(event, context):
+        return {"message": "hi"}
+
+    dummy(data=mock_event)
+    dummy_handler(mock_event, lambda_context)
+
+    assert len(persistence_store.client.method_calls) == 4
+
+
 @pytest.mark.parametrize("idempotency_config", [{"use_local_cache": True}], indirect=True)
 def test_idempotent_function_duplicates(
     idempotency_config: IdempotencyConfig,