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Types

  • Start here: Credentials in a config object
  • Common recipes: annotate a settings field that holds a connection URL with SecretUrl[RedisDsn] so the password never reaches a log line, and read it back with get_secret_value().

grelmicro.types

Shared types used across grelmicro modules and in user configuration.

LogLevel 

LogLevel = Literal[
    "DEBUG", "INFO", "WARNING", "ERROR", "CRITICAL"
]

Standard logging level names, matching logging.getLevelName output.

Environment 

Environment = Literal[
    "development", "test", "staging", "production"
]

Deployment tier the application runs in.

The well-known values of the OpenTelemetry deployment.environment.name attribute. Grelmicro(environment=...) and GREL_ENVIRONMENT take one, and staging and production turn the backend scope check into an error. A tier your organisation calls something else maps onto the closest of the four.

BackendScope 

BackendScope = Literal['process', 'host', 'cluster']

How far a backend shares the state it holds.

Ordered: process is one process (Memory), host is the processes on one host (SQLite), cluster is every process that connects to the backend (Redis, Valkey, Postgres, Kubernetes). An Adapter declares its own as a scope class attribute, and a Component requires at least one of them.

SecretUrl

Bases: Secret[UrlType], Generic[UrlType]

A URL whose embedded credentials never reach any output.

A URL carries its credentials inside itself: the password sits in the userinfo section (redis://user:password@host) and tokens often ride in the query string (?api_key=...). A plain URL field puts those in repr(), model_dump(), model_dump_json(), and any log line that prints the settings object.

SecretUrl shows the URL with its credentials replaced by *** everywhere the value is displayed or dumped, so an operator still reads the scheme, host, port, and path. The real URL comes back from get_secret_value():

from pydantic import BaseModel, RedisDsn
from grelmicro.types import SecretUrl


class Settings(BaseModel):
    url: SecretUrl[RedisDsn]


settings = Settings(url="redis://app:hunter2@cache:6379/0")

print(repr(settings))
#> Settings(url=SecretUrl('redis://app:***@cache:6379/0'))

print(settings.url.get_secret_value())
#> redis://app:hunter2@cache:6379/0

Parametrize it with any pydantic URL type to keep that type's validation: SecretUrl[RedisDsn] accepts only Redis schemes, and SecretUrl[PostgresDsn] accepts the multi-host Postgres form. Unparametrized, SecretUrl accepts any URL. Use SecretUrl[str] for an endpoint that is not always a full URL, such as the host:port form the OTLP gRPC exporter takes.

Parametrized with anything that is not a URL or a string, the whole value is masked instead, since nothing can be redacted from it safely.

TimeZoneName

Bases: str

An IANA timezone name, such as UTC or Europe/Zurich.

Validation accepts any casing and stores the name in the casing the timezone database uses, so europe/zurich and Europe/Zurich behave the same on every filesystem.

A name is accepted only when zoneinfo can load it. An abbreviation that names no zone, such as PST, is rejected where it is written rather than at the first use of the value.