Selectively load Flask configuration values from environment variables at runtime; never store secrets in configuration files again.
Initialize Flask-Habitat before any other middleware that requires configuration from a habitat source (e.g. environment, filesystem, or some other user-defined source) in order for Flask config values to be replaced.
from flask import Flask
from flask_habitat import Habitat
from flask_sqlalchemy import SQLAlchemy
app = Flask(__name__)
# DATABASE is an environment variable expected to contain the dburi
app.config["SQLALCHEMY_DATABASE_URI"] = "$DATABASE"
app.config.from_envvar("APP_SETTINGS")
habitat = Habitat(app)
db = SQLAlchemy(app)Bear in mind that Flask-Habitat only looks for configuration values which are strings, which makes it compatible with any configuration format used, which is particularly beneficial when using YAML. Below is an example YAML-formatted config file using Flask-Environments:
COMMON: &common
SQLALCHEMY_URI: $DATABASE_URI
SECRET_KEY: $SECRET_KEY
TOKEN_SALT: $TOKEN_SALT
DEVELOPMENT:
<<: *common
DEBUG: True
PRODUCTION:
<<: *common
SERVER_NAME: $SERVER_NAME- HABITAT_SOURCE defines where configuration values will be pulled from,
e.g. the environment, a file, or in the future, some user-defined source.
Currently, the only supported value is
environment. - HABITAT_QUALIFIER defaults to
$, and is the prefix that will be expected when looking for placeholders in configuration values.