recipe_app/backend/knexfile.js

require('dotenv').config();

module.exports = {

  development: {
    client: 'postgresql',
    connection: {
      host: 'db',
      port: 5432,
      database: process.env.DB_NAME,
      user: process.env.DB_USER,
      password: process.env.DB_PASSWORD
    },
    pool: {
      min: 2,
      max: 10
    },
    migrations: {
      tableName: 'knex_migrations',
      directory: './migrations'
    }
  },

  production: {
    client: 'postgresql',
    connection: {
      database: 'my_db',
      user: 'username',
      password: 'password'
    },
    pool: {
      min: 2,
      max: 10
    },
    migrations: {
      tableName: 'knex_migrations'
    }
  }

};