Creating a new sqlite db on the fly when a new account gets created

one-sqlite-db-per-account.rb

# Source https://x.com/benigartenmann/status/1871117811072065877

class Account < GlobalRecord
  after_create_commit :create_shard

  private
  def create_shard
    yaml_config = YAML.load_file("config/database.yml", aliases: true)
    root_db_config = ActiveRecord::Base.connection_db_config.configuration_hash.deep_dup.freeze
    tenant_shard_config = root_db_config.merge(
      database: "storage/#{self.subdomain}.sqlite3",
      migrations_paths: "db/migrate"
    )
    yaml_config[Rails.env][self.subdomain] = JSON.parse(tenant_shard_config.to_json)

    File.open("config/database.yml", "w") do |f|
      YAML.dump(yaml_config, f)
    end

    db_config = ActiveRecord::DatabaseConfigurations::HashConfig.new(
      Rails.env,
      self.subdomain,
      tenant_shard_config
    )
    ActiveRecord::Base.configurations.configurations << db_config

    connected_shards = yaml_config[Rails.env].keys.each_with_object({}) do |shard, shards|
      sym_shard = shard.to_sym
      shards[sym_shard] = {
        writing: sym_shard,
        reading: sym_shard
      }
    end
    ApplicationRecord.connects_to(shards: connected_shards)

    ActiveRecord::Tasks::DatabaseTasks.with_temporary_connection(db_config) do
      ActiveRecord::Tasks::DatabaseTasks.migrate
      if ActiveRecord.dump_schema_after_migration
        schema_format = ENV.fetch("SCHEMA_FORMAT", ActiveRecord.schema_format).to_sym
        ActiveRecord::Tasks::DatabaseTasks.dump_schema(
          db_config,
          schema_format
        )
      end
    end
  end
end

Alternative: https://github.com/rails-on-services/apartment