Database Configuration

The database configuration file is config/database.yml. Inferno uses the Sequel gem to communicate with the database, which offers a wide range of configuration options, found here.

By default, Inferno uses SQLite. Unfortunately, SQLite is not suitable for use in a multi-user deployment. Multi-user deployments should use PostgreSQL instead. The following sections walk through setting up Inferno with PostgreSQL.

PostgreSQL with Docker

The easiest way to run a PostgreSQL service is by adding it to the docker-compose.yml file with the rest of Inferno’s services. To do so:

• Add gem 'pg' to Gemfile
• Add the following entry to docker-compose.yml:

  inferno_db:
    image: postgres:14.1-alpine
    mem_limit: 600m
    restart: unless-stopped
    volumes:
      - ./data/pg:/var/lib/postgresql/data
    environment:
      POSTGRES_HOST_AUTH_METHOD: trust
      POSTGRES_DB: inferno_production
  

• Add inferno_db to the depends_on for inferno and worker services in docker-compose.yml. For example:

  inferno:
    # ...
    depends_on:
      - validator_service
      - inferno_db
  worker:
    # ...
    depends_on:
      - redis
      - inferno_db
  

• Use the following for the production configuration in config/database.yml:

  production:
  adapter: postgres
  database: inferno_production
  max_connections: 10
  user: postgres
  host: inferno_db
  

PostgreSQL as a Separate Service

If you have an existing PostgreSQL service that you would like to use, you can use it with the following steps:

• Add gem 'pg' to Gemfile
• In config/database.yml, change the adapter in the production entry to postgres, and supply the database, user, password, host, and port for the PostgreSQL database

Note: If you are using replication, for example with AWS RDS, you may encounter the error cannot update table "schema_info" because it does not have a replica identity when first setting up Inferno. If this occurs, run the following command in the database:

ALTER TABLE schema_info REPLICA IDENTITY FULL;