entity pattern

entity.go

package entity

import (
	"fmt"
	"log"
	"os"

	"github.com/jinzhu/gorm"
	_ "github.com/jinzhu/gorm/dialects/postgres"
	_ "github.com/jinzhu/gorm/dialects/sqlite"
)

// Session is a struct that contains a pointer to a GORM database. To create a new session, without passing one around, we rely on envrionment variables.
// Creating a new entity is as easy as
type Session struct {
	DB *gorm.DB
}

// NewSession uses envrionment variables to create a new services to connect to a GORM database.
// if the APP_ENV is set to testing, an in-memory database (sqlite) will be used for easy testing.
func NewSession() *Session {
	switch os.Getenv("APP_ENV") {
	case "testing":
		db, err := gorm.Open("sqlite", ":memory")
		if err != nil {
			log.Fatal(err)
		}
		return &Session{DB: db}
	default:
		db, err := gorm.Open("postgres", fmt.Sprintf(
			"host=%v user=%v dbname=%v sslmode=%v password=%v",
			os.Getenv("DB_HOST"), os.Getenv("DB_USER"), os.Getenv("DB_NAME"), os.Getenv("DB_MODE"), os.Getenv("DB_PASS"),
		))
		if err != nil {
			log.Fatal(err)
		}
		return &Session{DB: db}
	}
}

func logFatalIfError(err error) {
	if err != nil {
		log.Fatal(err)
	}
}