File size: 8,363 Bytes
e18c302 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 | """
AWS App Config configuration retrieval and caching utility
"""
from __future__ import annotations
import os
import warnings
from typing import TYPE_CHECKING
import boto3
from aws_lambda_powertools.shared import constants
from aws_lambda_powertools.shared.functions import (
resolve_env_var_choice,
resolve_max_age,
)
from aws_lambda_powertools.utilities.parameters.base import BaseProvider
from aws_lambda_powertools.utilities.parameters.constants import DEFAULT_MAX_AGE_SECS, DEFAULT_PROVIDERS
from aws_lambda_powertools.warnings import PowertoolsDeprecationWarning
if TYPE_CHECKING:
from botocore.config import Config
from mypy_boto3_appconfigdata.client import AppConfigDataClient
from aws_lambda_powertools.utilities.parameters.types import TransformOptions
class AppConfigProvider(BaseProvider):
"""
AWS App Config Provider
Parameters
----------
environment: str
Environment of the configuration to pass during client initialization
application: str, optional
Application of the configuration to pass during client initialization
config: botocore.config.Config, optional
Botocore configuration to pass during client initialization
boto3_session : boto3.session.Session, optional
Boto3 session to create a boto3_client from
boto3_client: AppConfigDataClient, optional
Boto3 AppConfigData Client to use, boto3_session will be ignored if both are provided
Example
-------
**Retrieves the latest configuration value from App Config**
>>> from aws_lambda_powertools.utilities import parameters
>>>
>>> appconf_provider = parameters.AppConfigProvider(environment="my_env", application="my_app")
>>>
>>> value : bytes = appconf_provider.get("my_conf")
>>>
>>> print(value)
My configuration value
**Retrieves a configuration value from App Config in another AWS region**
>>> from botocore.config import Config
>>> from aws_lambda_powertools.utilities import parameters
>>>
>>> config = Config(region_name="us-west-1")
>>> appconf_provider = parameters.AppConfigProvider(environment="my_env", application="my_app", config=config)
>>>
>>> value : bytes = appconf_provider.get("my_conf")
>>>
>>> print(value)
My configuration value
"""
def __init__(
self,
environment: str,
application: str | None = None,
config: Config | None = None,
boto_config: Config | None = None,
boto3_session: boto3.session.Session | None = None,
boto3_client: AppConfigDataClient | None = None,
):
"""
Initialize the App Config client
"""
super().__init__()
if config:
warnings.warn(
message="The 'config' parameter is deprecated in V3 and will be removed in V4. "
"Please use 'boto_config' instead.",
category=PowertoolsDeprecationWarning,
stacklevel=2,
)
if boto3_client is None:
boto3_session = boto3_session or boto3.session.Session()
boto3_client = boto3_session.client("appconfigdata", config=boto_config or config)
self.client = boto3_client
self.application = resolve_env_var_choice(
choice=application,
env=os.getenv(constants.SERVICE_NAME_ENV, "service_undefined"),
)
self.environment = environment
self.current_version = ""
self._next_token: dict[str, str] = {} # nosec - token for get_latest_configuration executions
# Dict to store the recently retrieved value for a specific configuration.
self.last_returned_value: dict[str, bytes] = {}
super().__init__(client=self.client)
def _get(self, name: str, **sdk_options) -> bytes:
"""
Retrieve a parameter value from AWS App config.
Parameters
----------
name: str
Name of the configuration
sdk_options: dict, optional
SDK options to propagate to `start_configuration_session` API call
"""
if name not in self._next_token:
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_token[name] = response_configuration["InitialConfigurationToken"]
# The new AppConfig APIs require two API calls to return the configuration
# First we start the session and after that we retrieve the configuration
# We need to store the token to use in the next execution
response = self.client.get_latest_configuration(ConfigurationToken=self._next_token[name])
return_value = response["Configuration"].read()
self._next_token[name] = response["NextPollConfigurationToken"]
# The return of get_latest_configuration can be null because this value is supposed to be cached
# on the customer side.
# We created a dictionary that stores the most recently retrieved value for a specific configuration.
# See https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/appconfigdata/client/get_latest_configuration.html
if return_value:
self.last_returned_value[name] = return_value
return self.last_returned_value[name]
def _get_multiple(self, path: str, **sdk_options) -> dict[str, str]:
"""
Retrieving multiple parameter values is not supported with AWS App Config Provider
"""
raise NotImplementedError()
def get_app_config(
name: str,
environment: str,
application: str | None = None,
transform: TransformOptions = None,
force_fetch: bool = False,
max_age: int | None = None,
**sdk_options,
) -> str | bytes | list | dict:
"""
Retrieve a configuration value from AWS App Config.
Parameters
----------
name: str
Name of the configuration
environment: str
Environment of the configuration
application: str
Application of the configuration
transform: str, optional
Transforms the content from a JSON object ('json') or base64 binary string ('binary')
force_fetch: bool, optional
Force update even before a cached item has expired, defaults to False
max_age: int, optional
Maximum age of the cached value
sdk_options: dict, optional
SDK options to propagate to `start_configuration_session` API call
Raises
------
GetParameterError
When the parameter provider fails to retrieve a parameter value for
a given name.
TransformParameterError
When the parameter provider fails to transform a parameter value.
Example
-------
**Retrieves the latest version of configuration value from App Config**
>>> from aws_lambda_powertools.utilities.parameters import get_app_config
>>>
>>> value = get_app_config("my_config", environment="my_env", application="my_env")
>>>
>>> print(value)
My configuration value
**Retrieves a configuration value and decodes it using a JSON decoder**
>>> from aws_lambda_powertools.utilities.parameters import get_app_config
>>>
>>> value = get_app_config("my_config", environment="my_env", application="my_env", transform='json')
>>>
>>> print(value)
My configuration's JSON value
"""
# If max_age is not set, resolve it from the environment variable, defaulting to DEFAULT_MAX_AGE_SECS
max_age = resolve_max_age(env=os.getenv(constants.PARAMETERS_MAX_AGE_ENV, DEFAULT_MAX_AGE_SECS), choice=max_age)
# Only create the provider if this function is called at least once
if "appconfig" not in DEFAULT_PROVIDERS:
DEFAULT_PROVIDERS["appconfig"] = AppConfigProvider(environment=environment, application=application)
return DEFAULT_PROVIDERS["appconfig"].get(
name,
max_age=max_age,
transform=transform,
force_fetch=force_fetch,
**sdk_options,
)
|