The database configuration section is a list of one or more connections. The main connection should be named master, and the connection parameters needed depends on the database being used (SQLite, MySQL, or PostgreSQL).
Here are some examples of common configurations.
master[driver] = sqlite
master[file] = "conf/site.db"
master[driver] = mysql
master[host] = "localhost:3306"
master[name] = my_db
master[user] = my_user
master[pass] = "********"
master[driver] = mysql
master[host] = "192.168.101.123:3306"
master[name] = my_db
master[user] = my_user
master[pass] = "********"
slave_one[driver] = mysql
slave_one[host] = "192.168.101.234:3306"
slave_one[name] = my_db
slave_one[user] = my_user
slave_one[pass] = "********"
master[driver] = pgsql
master[host] = "localhost:5432"
master[name] = my_db
master[user] = my_user
master[pass] = "********"