Source code for runway.lookups.handlers.env

"""Retrieve a value from an environment variable."""
# pyright: reportIncompatibleMethodOverride=none
from __future__ import annotations

from typing import TYPE_CHECKING, Any, Union

from typing_extensions import Final, Literal

from .base import LookupHandler

    from ...context import CfnginContext, RunwayContext

[docs]class EnvLookup(LookupHandler): """Environment variable Lookup.""" TYPE_NAME: Final[Literal["env"]] = "env" """Name that the Lookup is registered as."""
[docs] @classmethod def handle( # pylint: disable=arguments-differ cls, value: str, context: Union[CfnginContext, RunwayContext], *__args: Any, **__kwargs: Any, ) -> Any: """Retrieve an environment variable. The value is retrieved from a copy of the current environment variables that is saved to the context object. These environment variables are manipulated at runtime by Runway to fill in additional values such as ``DEPLOY_ENVIRONMENT`` and ``AWS_REGION`` to match the current execution. Args: value: The value passed to the Lookup. context: The current context object. Raises: ValueError: Unable to find a value for the provided query and a default value was not provided. """ query, args = cls.parse(value) result = context.env.vars.get(query, args.pop("default", "")) if result != "": # allows for False bool and NoneType results return cls.format_results(result, **args) raise ValueError(f'"{value}" does not exist in the environment')