How To Overwrite Dynaconf Variables For Testing In Python

What is Dynaconf and Why use it?

Dynaconf is a flexible, multi-environment configuration management tool for Python applications.

Traditionally, developers handled configurations using separate files for each environment (like settings.py or .env files).

While this works, it often requires manual changes at runtime or hardcoding values for different environments.

It supports environment variables, .env files, and even hierarchical settings stored in JSON, YAML, or TOML.

Initialize Dynaconf

To initialize Dynaconf run,

$ dynaconf init -f toml

It will create the following

.  
├── config.py       # Where you import your settings object (required)  
├── .secrets.toml   # Sensitive data like passwords and tokens (optional)  
└── settings.toml   # Application settings (optional)

Dynaconf Configuration

Place the settings.toml file at the root of the repo and define your settings.

[development]  
DEBUG = true  
DATABASE_URL = "sqlite:///development.db"  
  
[testing]  
DEBUG = true  
DATABASE_URL = "sqlite:///testing.db"  
  
[production]  
DEBUG = false  
DATABASE_URL = "postgresql://user:pass@localhost/db"

We have 3 environments — development , testing and production .

Managing Secrets with Dynaconf

1. Using .secrets Files

Dynaconf supports storing sensitive data in a .secrets file (e.g., .secrets.toml, .secrets.yaml, etc.).

2. Vault Integration

For more secure storage, Dynaconf can load secrets from a Vault server (e.g., HashiCorp Vault).

To use Vault with Dynaconf:

• Set up a Vault server (locally or via Docker).

• Install Dynaconf with Vault support: pip install dynaconf[vault]

• Configure Vault in your .env or environment variables

VAULT_ENABLED_FOR_DYNACONF=true  
VAULT_URL_FOR_DYNACONF="[http://localhost:8200](http://localhost:8200/)"  
VAULT_TOKEN_FOR_DYNACONF="your-root-token"

3. Redis for Secrets Storage

To use Redis:

• Set up Redis via Docker: docker run -d -p 6379:6379 redis

• Install Dynaconf with Redis support: pip install dynaconf[redis]

• Configure Redis in your .env or environment variables:

REDIS_ENABLED_FOR_DYNACONF=true    
REDIS_HOST_FOR_DYNACONF=localhost    
REDIS_PORT_FOR_DYNACONF=6379

Secrets can now be stored and accessed from Redis, ensuring they are centrally managed and securely distributed across all instances of your application.

4. Using .env Files

For simple use cases, Dynaconf can load environment variables from a .env file.

This file can hold your secrets in plain text, which is then loaded by Dynaconf when the application starts. To enable .env file loading, use:

from dynaconf import Dynaconf
settings = Dynaconf(load_dotenv=True)

Example .env file:

DYNACONF_API_KEY=12345abcdef  
DYNACONF_DB_PASSWORD=supersecurepassword