Configuration¶

LightningROD is configured through environment variables, loaded from a .env file.

Environment Variables¶

Example¶

# PostgreSQL
POSTGRES_USER=lightningrod
POSTGRES_PASSWORD=changeme
POSTGRES_DB=lightningrod
POSTGRES_HOST=localhost

# Application
APP_PORT=8000
DEBUG=false

How Configuration is Loaded¶

The application uses pydantic-settings to read environment variables. The configuration class assembles the async database URL from the individual PostgreSQL variables:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23

from pydantic_settings import BaseSettings, SettingsConfigDict


class Settings(BaseSettings):
    model_config = SettingsConfigDict(env_file=".env", extra="ignore")

    postgres_user: str
    postgres_password: str
    postgres_db: str
    postgres_host: str = "localhost"
    app_port: int = 8000
    debug: bool = False

    @property
    def database_url(self) -> str:
        return (
            f"postgresql+asyncpg://{self.postgres_user}:"
            f"{self.postgres_password}@{self.postgres_host}/"
            f"{self.postgres_db}"
        )


settings = Settings()

Docker Compose Override¶

When running with Docker Compose, the POSTGRES_HOST is automatically set to db (the service name) via the environment section in docker-compose.yml:

  web:
    build:
      context: .
      dockerfile: Dockerfile
    env_file: .env
    environment:
      - POSTGRES_HOST=db

You do not need to change POSTGRES_HOST in your .env file when using Docker Compose.

In-App Settings¶

Some settings are configured through the web UI rather than environment variables:

• Charging networks -- Per-network electricity costs ($/kWh)
• Gas comparison -- MPG and gas price for savings calculations
• Unit preferences -- US (mi/kWh) or EU (km/kWh)
• Comparison toggles -- Show or hide cost comparison sections

These are stored in the app_settings database table and managed at /settings.