add backend tpl

backend_v1/database/database.go

@@ -0,0 +1,59 @@
+package database
+
+import (
+	"database/sql"
+	"embed"
+	"sync"
+
+	"git.ipao.vip/rogeecn/mp-qvyun/conf"
+	"github.com/gofiber/fiber/v3/log"
+	_ "github.com/lib/pq"
+	"github.com/pkg/errors"
+)
+
+//go:embed migrations/*
+var MigrationFS embed.FS
+
+var (
+	mutex sync.Mutex
+	db    *sql.DB
+)
+
+func Close() error {
+	if db == nil {
+		return nil
+	}
+	return db.Close()
+}
+
+func GetDB(config conf.Database) (*sql.DB, error) {
+	mutex.Lock()
+	defer mutex.Unlock()
+
+	if db != nil {
+		return db, nil
+	}
+
+	once := sync.OnceValues(func() (*sql.DB, error) {
+		log.Debugf("connect postgres with dsn: '%s'", config.DSN())
+		db, err := sql.Open("postgres", config.DSN())
+		if err != nil {
+			return nil, errors.Wrap(err, "connect database")
+		}
+
+		if err := db.Ping(); err != nil {
+			db.Close()
+			return nil, errors.Wrap(err, "ping database")
+		}
+
+		return db, err
+	})
+
+	var err error
+	db, err = once()
+	if err != nil {
+		return nil, err
+	}
+
+	return db, err
+}