environ-config: Application Configuration With Env Variables
environ-config allows you to configure your applications using environment variables – as recommended in The Twelve-Factor App methodology – with elegant, boilerplate-free, and declarative code:
>>> import environ
>>> # Extracts secrets from Vault-via-envconsul: 'secret/your-app':
>>> vault = environ.secrets.VaultEnvSecrets(vault_prefix="SECRET_YOUR_APP")
>>> @environ.config(prefix="APP")
... class AppConfig:
... @environ.config
... class DB:
... name = environ.var("default_db")
... host = environ.var("default.host")
... port = environ.var(5432, converter=int) # Use attrs's converters and validators!
... user = environ.var("default_user")
... password = vault.secret()
...
... env = environ.var()
... lang = environ.var(name="LANG") # It's possible to overwrite the names of variables.
... db = environ.group(DB)
... awesome = environ.bool_var()
>>> cfg = environ.to_config(
... AppConfig,
... environ={
... "APP_ENV": "dev",
... "APP_DB_HOST": "localhost",
... "LANG": "C",
... "APP_AWESOME": "yes", # true and 1 work too, everything else is False
... # Vault-via-envconsul-style var name:
... "SECRET_YOUR_APP_DB_PASSWORD": "s3kr3t",
... }) # Uses os.environ by default.
>>> cfg
AppConfig(env='dev', lang='C', db=AppConfig.DB(name='default_db', host='localhost', port=5432, user='default_user', password=<SECRET>), awesome=True)
>>> cfg.db.password
's3kr3t'AppConfig.from_environ({...}) is equivalent to the code above, depending on your taste.
Features
- Declarative & boilerplate-free.
- Nested configuration from flat environment variable names.
- Default & mandatory values: enforce configuration structure without writing a line of code.
- Built on top of attrs which gives you data validation and conversion for free.
- Pluggable secrets extraction.
Ships with:
- HashiCorp Vault support via envconsul.
- INI files, because secrets in env variables are icky.
- Helpful debug logging that will tell you which variables are present and what environ-config is looking for.
- Built-in dynamic help documentation generation.
You can find the full documentation including a step-by-step tutorial on Read the Docs.
Project Information
environ-config is released under the Apache License 2.0 license. It targets Python 3.7 and newer, and PyPy. Development takes place on GitHub.