init push

backend/store/pg/pg.go

@@ -0,0 +1,80 @@
+package pg
+
+import (
+	"database/sql"
+	"fmt"
+	"log"
+	"os"
+	"time"
+
+	"github.com/golang-migrate/migrate/v4"
+	migratePG "github.com/golang-migrate/migrate/v4/database/postgres"
+	_ "github.com/golang-migrate/migrate/v4/source/file"
+	"gorm.io/driver/postgres"
+	"gorm.io/gorm"
+	"gorm.io/gorm/logger"
+
+	"github.com/chaitin/panda-wiki/config"
+)
+
+type DB struct {
+	*gorm.DB
+}
+
+func NewDB(config *config.Config) (*DB, error) {
+	dsn := config.PG.DSN
+	// same as gorm logger.Default, but without colorful output and ignore record not found error
+	newLogger := logger.New(log.New(os.Stdout, "\r\n", log.LstdFlags), logger.Config{
+		SlowThreshold:             200 * time.Millisecond,
+		LogLevel:                  logger.Warn,
+		IgnoreRecordNotFoundError: true,
+		Colorful:                  false,
+	})
+	db, err := gorm.Open(postgres.Open(dsn), &gorm.Config{
+		TranslateError: true,
+		Logger:         newLogger,
+	})
+	if err != nil {
+		return nil, err
+	}
+	// create raglite database if not exists
+	var exists bool
+	if err := db.Raw("SELECT EXISTS(SELECT 1 FROM pg_database WHERE datname = 'raglite')").Scan(&exists).Error; err != nil {
+		return nil, err
+	}
+	if !exists {
+		if err := db.Exec("CREATE DATABASE raglite").Error; err != nil {
+			return nil, err
+		}
+	}
+	if err := doMigrate(dsn); err != nil {
+		return nil, err
+	}
+
+	return &DB{DB: db}, nil
+}
+
+func doMigrate(dsn string) error {
+	db, err := sql.Open("postgres", dsn)
+	if err != nil {
+		return fmt.Errorf("open db failed: %w", err)
+	}
+	driver, err := migratePG.WithInstance(db, &migratePG.Config{})
+	if err != nil {
+		return fmt.Errorf("with instance failed: %w", err)
+	}
+	m, err := migrate.NewWithDatabaseInstance(
+		"file://migration",
+		"postgres", driver)
+	if err != nil {
+		return fmt.Errorf("new with database instance failed: %w", err)
+	}
+	if err := m.Up(); err != nil {
+		if err == migrate.ErrNoChange {
+			return nil
+		}
+		return fmt.Errorf("migrate db failed: %w", err)
+	}
+
+	return nil
+}