Examples

• S3

from dataclasses import InitVar
from os.path import exists
from typing import Literal, Optional

from cornflakes import AnyUrl, Loader, config, config_field
from cornflakes.common import default_ca_path


def endpoint_validation(
    endpoint_url: str,
    values: dict,
):
    """Method to validate the endpoint_url and add scheme if missing.

    .. highlight: python

    :code:`client = boto3.client(**Boto3ClientConfig().to_dict())`
    """
    return (
        f'{"https://" if values.get("use_https") else "http://"}' f"{endpoint_url}"
        if "http" not in endpoint_url
        else endpoint_url
    )


def ca_path_validation(ca_path: str):
    """Method check if the ca_path exists."""
    if not exists(ca_path):
        raise Exception(f"CA-Path {ca_path} does not exists!")
    return ca_path


@config(
    files=["~/.s3cfg", "~/.aws/credentials", "~/.aws/config", "~/.custom-rc"],  # default s3 config file paths
    is_list=True,  # read instances into a list (not a dict -> by default for each section)
    frozen=True,  # make the config immutable
    validate=True,  # activate validation and type checking
    eval_env=True,  # evaluate environment variables
    default_loader=Loader.INI_LOADER,  # use the ini loader as default
)
class Boto3ClientConfig:
    """Config class for the boto3 client.

    This class is used to configure the boto3 client.
    Required configs are endpoint_url, access_key and secret_key (no_default argument).
    The values for access_key and secret_key are invisible in repr methods (repr = False).
    The alias argument is used to set the alias key searched in the files.
    """

    use_https: InitVar[bool] = config_field(alias=["signurl_use_https", "use_https"], default=True)
    endpoint_url: AnyUrl = config_field(
        alias=["endpoint-url", "host_base"], validator=endpoint_validation, no_default=True
    )
    aws_access_key_id: str = config_field(alias=["access_key"], repr=False, no_default=True)
    aws_secret_access_key: str = config_field(alias=["secret_key"], repr=False, no_default=True)
    service_name: Literal["s3", "ec2"] = "s3"
    region_name: Optional[str] = config_field(default=None, alias=["bucket_location", "region", "aws_default_region"])
    verify: str = config_field(default_factory=default_ca_path, validator=ca_path_validation)

• FastAPI

from typing import List, Optional

from cornflakes import AnyUrl, config, config_field


@config(files=".env", eval_env=True, validate=True)
class Settings:
    """Some Fastapi settings."""

    PROJECT_NAME: str = "fastapi-boilerplate"

    SENTRY_DSN: Optional[AnyUrl] = None

    API_PATH: str = "/api/v1"

    ACCESS_TOKEN_EXPIRE_MINUTES: int = 7 * 24 * 60  # 7 days

    BACKEND_CORS_ORIGINS: List[AnyUrl] = None

    # The following variables need to be defined in environment
    TEST_DATABASE_URL: Optional[AnyUrl] = None
    DATABASE_URL: AnyUrl = config_field(no_default=True)  # no default value (required)
    ASYNC_DATABASE_URL: Optional[AnyUrl] = None

    SECRET_KEY: str = ""
    #  END: required environment variables