Models¶

Common data models used across Lambda handlers.

Data models for Lambda handler configuration and execution.

Provides models for Lambda context, handler requests, and serialization utilities.

DefaultLambdaContext `dataclass` ¶

DefaultLambdaContext(
    _function_name=(
        lambda: get_env_var(AWS_LAMBDA_FUNCTION_NAME_KEY)
        or DEFAULT_AWS_LAMBDA_FUNCTION_NAME
    )(),
    _function_version=(
        lambda: get_env_var(
            AWS_LAMBDA_FUNCTION_VERSION_KEY,
            default_value="1.0",
        )
    )(),
    _invoked_function_arn=(
        lambda: get_env_var(
            AWS_LAMBDA_FUNCTION_ARN_KEY, default_value=""
        )
    )(),
    _memory_limit_in_mb=(
        lambda: int(
            get_env_var(
                AWS_LAMBDA_FUNCTION_MEMORY_SIZE_KEY,
                default_value="1024",
            )
        )
    )(),
    _aws_request_id=(
        lambda: get_env_var(
            AWS_LAMBDA_FUNCTION_REQUEST_ID_KEY,
            default_value="",
        )
    )(),
    _log_group_name=(
        lambda: get_env_var(
            AWS_LAMBDA_LOG_GROUP_NAME_KEY, default_value=""
        )
    )(),
    _log_stream_name=(
        lambda: get_env_var(
            AWS_LAMBDA_LOG_STREAM_NAME_KEY, default_value=""
        )
    )(),
    _identity=(lambda: LambdaCognitoIdentity())(),
    _client_context=(lambda: LambdaClientContext())(),
)

Bases: LambdaContext

Standard implementation of LambdaContext for non-Lambda environments.

Provides a mock Lambda context for running handlers outside of AWS Lambda, such as in Docker containers or for local testing. All fields can be configured via environment variables.

LambdaHandlerRequest ¶

Bases: PydanticBaseModel

Request model for dynamic Lambda handler invocation.

Contains the handler reference and event payload for routing Lambda invocations to the appropriate handler.

Attributes:

Name	Type	Description
`handler`	`Annotated[LambdaHandlerType, BeforeValidator(deserialize_handler), PlainSerializer(lambda handler: serialize_handler(handler))]`	The Lambda handler function to invoke.
`event`	`LambdaEvent`	The event payload to pass to the handler.

deserialize_handler ¶

deserialize_handler(handler)

Deserialize a handler from its qualified name.

Loads a handler from its fully qualified module path. Supports both function handlers and LambdaHandler subclasses.

Parameters:

Name	Type	Description	Default
`handler`	`str`	The fully qualified handler path (e.g., 'module.submodule.HandlerClass').	required

Returns:

Type	Description
`LambdaHandlerType`	The Lambda handler function ready to be invoked.

Raises:

Type	Description
`ValueError`	If the handler cannot be deserialized or is not a valid handler type.

Example

handler = deserialize_handler('my_module.MyHandler')
response = handler(event, context)

Source code in src/aibs_informatics_aws_lambda/common/models.py

def deserialize_handler(handler: str | LambdaHandlerType) -> LambdaHandlerType:
    """Deserialize a handler from its qualified name.

    Loads a handler from its fully qualified module path. Supports both
    function handlers and LambdaHandler subclasses.

    Args:
        handler (str): The fully qualified handler path (e.g., 'module.submodule.HandlerClass').

    Returns:
        The Lambda handler function ready to be invoked.

    Raises:
        ValueError: If the handler cannot be deserialized or is not a valid handler type.

    Example:
        ```python
        handler = deserialize_handler('my_module.MyHandler')
        response = handler(event, context)
        ```
    """
    if not isinstance(handler, str):
        if not callable(handler):
            raise ValueError(
                f"Invalid handler type: expected a callable or fully qualified handler path "
                f"string, got {type(handler).__name__}."
            )
        return cast(LambdaHandlerType, handler)
    handler_components = handler.split(".")

    handler_module = as_module_type(".".join(handler_components[:-1]))
    handler_name = handler_components[-1]

    handler_code = getattr(handler_module, handler_name)
    if inspect.isfunction(handler_code):
        return cast(LambdaHandlerType, handler_code)
    elif inspect.isclass(handler_code) and issubclass(handler_code, LambdaHandler):
        logger.debug(f"Handler code is a class: {handler_code}. Calling `get_handler`...")
        return handler_code.get_handler()
    else:
        raise ValueError(
            f"Unable to deserialize handler: {handler}. "
            "It is not a function or a subclass of LambdaHandler."
        )

serialize_handler ¶

serialize_handler(handler)

Serialize a Lambda handler to its qualified name.

For closures (e.g., from LambdaHandler.get_handler()), the function's __qualname__ points to the closure definition site rather than the module-level variable that holds it. This searches sys.modules for a global variable that references the exact handler object, so that constructor arguments passed to get_handler() are preserved on round-trip.