relynolli-server/internal/database.go

package internal

import (
	"database/sql"
	"fmt"
	"github.com/uptrace/bun/extra/bundebug"
	"log"
	"os"
	"sync"

	_ "github.com/go-sql-driver/mysql"
	"github.com/uptrace/bun"
	"github.com/uptrace/bun/dialect/mysqldialect"
)

type database struct {
	instance *bun.DB
}

type Database interface {
	GetInstance() *bun.DB
}

var (
	instance *database = nil
	once     sync.Once
)

func initialize() {
	db, err := sql.Open("mysql", fmt.Sprintf(
		"%s:%s@tcp(%s)/%s",
		os.Getenv("MYSQL_USER"),
		os.Getenv("MYSQL_PASSWORD"),
		os.Getenv("MYSQL_HOST"),
		os.Getenv("MYSQL_DATABASE")))

	if err != nil {
		panic(err)
	}

	// Resolve instances of bun

	ormDb := bun.NewDB(db, mysqldialect.New())
	ormDb.AddQueryHook(bundebug.NewQueryHook())

	// Check Connection
	conErr := ormDb.Ping()

	if conErr != nil {
		panic(conErr)
	}

	log.Println("Connection to db succeded")
	instance = &database{instance: ormDb}
}

func InitDatabase() Database {
	if instance == nil {
		once.Do(initialize)
	}
	return instance
}

func (d *database) GetInstance() *bun.DB {
	return d.instance
}