feat(parameters): migrate AppConfig to new APIs due to API deprecation

aws_lambda_powertools/utilities/parameters/appconfig.py

@@ -5,20 +5,17 @@
 
 import os
 from typing import TYPE_CHECKING, Any, Dict, Optional, Union
-from uuid import uuid4
 
 import boto3
 from botocore.config import Config
 
 if TYPE_CHECKING:
-    from mypy_boto3_appconfig import AppConfigClient
+    from mypy_boto3_appconfigdata import AppConfigDataClient
 
 from ...shared import constants
 from ...shared.functions import resolve_env_var_choice
 from .base import DEFAULT_MAX_AGE_SECS, DEFAULT_PROVIDERS, BaseProvider
 
-CLIENT_ID = str(uuid4())
-
 
 class AppConfigProvider(BaseProvider):
     """
@@ -34,8 +31,8 @@ class AppConfigProvider(BaseProvider):
         Botocore configuration to pass during client initialization
     boto3_session : boto3.session.Session, optional
             Boto3 session to create a boto3_client from
-    boto3_client: AppConfigClient, optional
-            Boto3 AppConfig Client to use, boto3_session will be ignored if both are provided
+    boto3_client: AppConfigDataClient, optional
+            Boto3 AppConfigData Client to use, boto3_session will be ignored if both are provided
 
     Example
     -------
@@ -73,16 +70,16 @@ def __init__(
         application: Optional[str] = None,
         config: Optional[Config] = None,
         boto3_session: Optional[boto3.session.Session] = None,
-        boto3_client: Optional["AppConfigClient"] = None,
+        boto3_client: Optional["AppConfigDataClient"] = None,
     ):
         """
         Initialize the App Config client
         """
 
         super().__init__()
 
-        self.client: "AppConfigClient" = self._build_boto3_client(
-            service_name="appconfig", client=boto3_client, session=boto3_session, config=config
+        self.client: "AppConfigDataClient" = self._build_boto3_client(
+            service_name="appconfigdata", client=boto3_client, session=boto3_session, config=config
         )
 
         self.application = resolve_env_var_choice(
@@ -91,6 +88,9 @@ def __init__(
         self.environment = environment
         self.current_version = ""
 
+        self.next_call = ""
+        self.last_returned_value = ""
+
     def _get(self, name: str, **sdk_options) -> str:
         """
         Retrieve a parameter value from AWS App config.
@@ -100,16 +100,23 @@ def _get(self, name: str, **sdk_options) -> str:
         name: str
             Name of the configuration
         sdk_options: dict, optional
-            Dictionary of options that will be passed to the client's get_configuration API call
+            Dictionary of options that will be passed to the client's start_configuration_session API call
         """
+        if not self.next_call:
+            sdk_options["ConfigurationProfileIdentifier"] = name
+            sdk_options["ApplicationIdentifier"] = self.application
+            sdk_options["EnvironmentIdentifier"] = self.environment
+            response_configuration = self.client.start_configuration_session(**sdk_options)
+            self.next_call = response_configuration["InitialConfigurationToken"]
 
-        sdk_options["Configuration"] = name
-        sdk_options["Application"] = self.application
-        sdk_options["Environment"] = self.environment
-        sdk_options["ClientId"] = CLIENT_ID
+        response = self.client.get_latest_configuration(ConfigurationToken=self.next_call)
+        return_value = response["Configuration"].read()
+        self.next_call = response["NextPollConfigurationToken"]
 
-        response = self.client.get_configuration(**sdk_options)
-        return response["Content"].read()  # read() of botocore.response.StreamingBody
+        if return_value:
+            self.last_returned_value = return_value
+
+        return self.last_returned_value
 
     def _get_multiple(self, path: str, **sdk_options) -> Dict[str, str]:
         """
@@ -145,7 +152,7 @@ def get_app_config(
     max_age: int
         Maximum age of the cached value
     sdk_options: dict, optional
-        Dictionary of options that will be passed to the boto client get_configuration API call
+        Dictionary of options that will be passed to the boto client start_configuration_session API call
 
     Raises
     ------
@@ -180,8 +187,6 @@ def get_app_config(
     if "appconfig" not in DEFAULT_PROVIDERS:
         DEFAULT_PROVIDERS["appconfig"] = AppConfigProvider(environment=environment, application=application)
 
-    sdk_options["ClientId"] = CLIENT_ID
-
     return DEFAULT_PROVIDERS["appconfig"].get(
         name, max_age=max_age, transform=transform, force_fetch=force_fetch, **sdk_options
     )

aws_lambda_powertools/utilities/parameters/base.py

@@ -15,7 +15,7 @@
 from .exceptions import GetParameterError, TransformParameterError
 
 if TYPE_CHECKING:
-    from mypy_boto3_appconfig import AppConfigClient
+    from mypy_boto3_appconfigdata import AppConfigDataClient
     from mypy_boto3_dynamodb import DynamoDBServiceResource
     from mypy_boto3_secretsmanager import SecretsManagerClient
     from mypy_boto3_ssm import SSMClient
@@ -28,7 +28,7 @@
 TRANSFORM_METHOD_JSON = "json"
 TRANSFORM_METHOD_BINARY = "binary"
 SUPPORTED_TRANSFORM_METHODS = [TRANSFORM_METHOD_JSON, TRANSFORM_METHOD_BINARY]
-ParameterClients = Union["AppConfigClient", "SecretsManagerClient", "SSMClient"]
+ParameterClients = Union["AppConfigDataClient", "SecretsManagerClient", "SSMClient"]
 
 
 class BaseProvider(ABC):

docs/upgrade.md

@@ -13,6 +13,7 @@ Changes at a glance:
 * The API for **event handler's `Response`** has minor changes to support multi value headers and cookies.
 * The **legacy SQS batch processor** was removed.
 * The **Idempotency key** format changed slightly, invalidating all the existing cached results.
+* The **Feature Flags and AppConfig Parameter utility** API calls have changed and you must add new IAM permissions to Lambda.
 
 ???+ important
     Powertools for Python v2 drops suport for Python 3.6, following the Python 3.6 End-Of-Life (EOL) reached on December 23, 2021.
@@ -154,3 +155,9 @@ Prior to this change, the Idempotency key was generated using only the caller fu
 After this change, the key is generated using the `module name` + `qualified function name` + `idempotency key` (e.g: `app.classExample.function#app.handler#282e83393862a613b612c00283fef4c8`).
 
 Using qualified names prevents distinct functions with the same name to contend for the same Idempotency key.
+
+## Feature Flags and AppConfig Parameter utility
+
+The current API is [deprecated](https://docs.aws.amazon.com/appconfig/2019-10-09/APIReference/API_GetConfiguration.html) for new accounts and we had to change this.
+
+No changes are required to your code, but you must add `appconfig:GetLatestConfiguration` and `appconfig:StartConfigurationSession` IAM permissions for this to work in your Lambdas.