Environment Configuration

Mapping Connection Strings

Inside the docker-compose.yml file, the `backend` service requires strict environment variables to discover databases within the isolated app-network bridge.

environment:
  - BASE_FRONTEND_URL=http://localhost
  - BASE_API_URL=http://localhost/api
  - DATABASE_DEFAULT=SQLITE
  - SQLITE_DATABASE=/app/storage/database.sqlite

Variables Explained

• BASE_FRONTEND_URL & BASE_API_URL (CRITICAL): Defines the public URLs where customers access the nLink dashboard and API. This is mandatory for SAML SSO workflows and OAuth callbacks to function correctly.
• CREDENTIAL_SECRET_KEY (CRITICAL): A 32-character secure string used by the engine to perform AES-GCM encryption on all user credentials stored in the database. Do not lose or change this key after initialization, or existing credentials will be undecryptable.
• DATABASE_DEFAULT: Specifies the primary database engine the system should use. Accepted values are SQLITE, MYSQL, or POSTGRES.
• MYSQL_HOST / POSTGRES_HOST: These variables define the internal DNS hostnames of your database containers. Because of Docker's internal networking, assigning =mysql_db automatically routes the connection to the container named `mysql_db`. You do not need to input `localhost` or an IP address.
• REDIS_ADDR: The complete address and port string for the Redis cache cluster (e.g., redis_server:6379 inside the docker network).
• NLINK_HEALING_OPENAI_KEY: Activates the AI Self-Healing Engine. Supply an OpenAI API key (sk-...) to allow the system to automatically repair Data Mapping errors and JSON structural changes from third-party APIs during execution.

Using a `.env` File

Hardcoding secret values inside `docker-compose.yml` isn't recommended for production setups. Instead, map these dynamically using a .env file placed in the same directory:

# .env
BASE_FRONTEND_URL=https://app.yourdomain.com
BASE_API_URL=https://app.yourdomain.com/api
CREDENTIAL_SECRET_KEY=your_secure_32_char_random_string
DATABASE_DEFAULT=SQLITE
SQLITE_DATABASE=/app/storage/database.sqlite

Then adapt your compose file to interpolate them:

environment:
  - BASE_FRONTEND_URL=${BASE_FRONTEND_URL}
  - BASE_API_URL=${BASE_API_URL}
  - CREDENTIAL_SECRET_KEY=${CREDENTIAL_SECRET_KEY}
  - DATABASE_DEFAULT=${DATABASE_DEFAULT}
  - SQLITE_DATABASE=${SQLITE_DATABASE}