AppConfig

Advanced feature flags utility

Usage Documentation

Feature Flags

CLASS	DESCRIPTION
AppConfigStore

AppConfigStore

AppConfigStore(environment: str, application: str, name: str, max_age: int = 5, sdk_config: Config | None = None, envelope: str | None = '', jmespath_options: dict | None = None, logger: Logger | Logger | None = None, boto_config: Config | None = None, boto3_session: Session | None = None, boto3_client: AppConfigDataClient | None = None)

Bases: StoreProvider

PARAMETER	DESCRIPTION
environment	Appconfig environment, e.g. 'dev/test' etc. TYPE: str
application	AppConfig application name, e.g. 'powertools' TYPE: str
name	AppConfig configuration name e.g. my_conf TYPE: str
max_age	cache expiration time in seconds, or how often to call AppConfig to fetch latest configuration TYPE: int DEFAULT: 5
sdk_config	Botocore Config object to pass during client initialization TYPE: Config | None DEFAULT: None
envelope	JMESPath expression to pluck feature flags data from config TYPE: str | None DEFAULT: ''
jmespath_options	Alternative JMESPath options to be included when filtering expr TYPE: dict | None DEFAULT: None
logger	Used to log messages. If None is supplied, one will be created. TYPE: Logger | Logger | None DEFAULT: None
boto_config	Botocore configuration to pass during client initialization TYPE: Config | None DEFAULT: None
boto3_session	Boto3 session to use for AWS API communication TYPE: Session DEFAULT: None
boto3_client	Boto3 AppConfigDataClient Client to use, boto3_session and boto_config will be ignored if both are provided TYPE: AppConfigDataClient DEFAULT: None

METHOD	DESCRIPTION
get_configuration	Fetch feature schema configuration from AWS AppConfig

ATTRIBUTE	DESCRIPTION
get_raw_configuration	Fetch feature schema configuration from AWS AppConfig TYPE: dict[str, Any]

Source code in aws_lambda_powertools/utilities/feature_flags/appconfig.py

def __init__(
    self,
    environment: str,
    application: str,
    name: str,
    max_age: int = 5,
    sdk_config: Config | None = None,
    envelope: str | None = "",
    jmespath_options: dict | None = None,
    logger: logging.Logger | Logger | None = None,
    boto_config: Config | None = None,
    boto3_session: boto3.session.Session | None = None,
    boto3_client: AppConfigDataClient | None = None,
):
    """This class fetches JSON schemas from AWS AppConfig

    Parameters
    ----------
    environment: str
        Appconfig environment, e.g. 'dev/test' etc.
    application: str
        AppConfig application name, e.g. 'powertools'
    name: str
        AppConfig configuration name e.g. `my_conf`
    max_age: int
        cache expiration time in seconds, or how often to call AppConfig to fetch latest configuration
    sdk_config: Config | None
        Botocore Config object to pass during client initialization
    envelope : str | None
        JMESPath expression to pluck feature flags data from config
    jmespath_options : dict | None
        Alternative JMESPath options to be included when filtering expr
    logger: A logging object
        Used to log messages. If None is supplied, one will be created.
    boto_config: botocore.config.Config, optional
        Botocore configuration to pass during client initialization
    boto3_session : boto3.Session, optional
        Boto3 session to use for AWS API communication
    boto3_client : AppConfigDataClient, optional
        Boto3 AppConfigDataClient Client to use, boto3_session and boto_config will be ignored if both are provided
    """
    super().__init__()
    self.logger = logger or logging.getLogger(__name__)
    self.environment = environment
    self.application = application
    self.name = name
    self.cache_seconds = max_age
    self.config = sdk_config or boto_config
    self.envelope = envelope
    self.jmespath_options = jmespath_options
    self._conf_store = AppConfigProvider(
        environment=environment,
        application=application,
        config=sdk_config or boto_config,
        boto3_client=boto3_client,
        boto3_session=boto3_session,
    )
    # Memoised envelope extraction: (raw document, extracted config). The Parameters cache hands back the
    # same raw dict until expiry, so we can reuse the extracted result rather than re-running the JMESPath
    # query and producing a new object on every call.
    self._last_extracted: tuple[dict[str, Any], dict[str, Any]] | None = None

    # Override the user agent to use "feature_flags" instead of "parameters"
    self._register_feature_flags_user_agent()

get_raw_configuration property

get_raw_configuration: dict[str, Any]

Fetch feature schema configuration from AWS AppConfig

get_configuration

get_configuration() -> dict[str, Any]

Fetch feature schema configuration from AWS AppConfig

If envelope is set, it'll extract and return feature flags from configuration, otherwise it'll return the entire configuration fetched from AWS AppConfig.

RAISES	DESCRIPTION
ConfigurationStoreError	Any validation error or AppConfig error that can occur

RETURNS	DESCRIPTION
dict[str, Any]	parsed JSON dictionary

Source code in aws_lambda_powertools/utilities/feature_flags/appconfig.py

def get_configuration(self) -> dict[str, Any]:
    """Fetch feature schema configuration from AWS AppConfig

    If envelope is set, it'll extract and return feature flags from configuration,
    otherwise it'll return the entire configuration fetched from AWS AppConfig.

    Raises
    ------
    ConfigurationStoreError
        Any validation error or AppConfig error that can occur

    Returns
    -------
    dict[str, Any]
        parsed JSON dictionary
    """
    config = self.get_raw_configuration

    if self.envelope:
        if self._last_extracted is not None and self._last_extracted[0] is config:
            self.logger.debug("Envelope enabled; reusing previously extracted config for cached document")
            return self._last_extracted[1]

        self.logger.debug("Envelope enabled; extracting data from config", extra={"envelope": self.envelope})
        extracted = jmespath_utils.query(
            data=config,
            envelope=self.envelope,
            jmespath_options=self.jmespath_options,
        )
        self._last_extracted = (config, extracted)
        return extracted

    return config