Support disabling database auto migration (#22053)

Gitea will migrate the database model version automatically, but it
should be able to be disabled and keep Gitea shutdown if the version is
not matched.

routers/common/db.go

@@ -12,6 +12,8 @@ import (
 	"code.gitea.io/gitea/models/migrations"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
+
+	"xorm.io/xorm"
 )
 
 // InitDBEngine In case of problems connecting to DB, retry connection. Eg, PGSQL in Docker Container on Synology
@@ -24,7 +26,7 @@ func InitDBEngine(ctx context.Context) (err error) {
 		default:
 		}
 		log.Info("ORM engine initialization attempt #%d/%d...", i+1, setting.Database.DBConnectRetries)
-		if err = db.InitEngineWithMigration(ctx, migrations.Migrate); err == nil {
+		if err = db.InitEngineWithMigration(ctx, migrateWithSetting); err == nil {
 			break
 		} else if i == setting.Database.DBConnectRetries-1 {
 			return err
@@ -36,3 +38,20 @@ func InitDBEngine(ctx context.Context) (err error) {
 	db.HasEngine = true
 	return nil
 }
+
+func migrateWithSetting(x *xorm.Engine) error {
+	if setting.Database.AutoMigration {
+		return migrations.Migrate(x)
+	}
+
+	if current, err := migrations.GetCurrentDBVersion(x); err != nil {
+		return err
+	} else if current < 0 {
+		// execute migrations when the database isn't initialized even if AutoMigration is false
+		return migrations.Migrate(x)
+	} else if expected := migrations.ExpectedVersion(); current != expected {
+		log.Fatal(`"database.AUTO_MIGRATION" is disabled, but current database version %d is not equal to the expected version %d.`+
+			`You can set "database.AUTO_MIGRATION" to true or migrate manually by running "gitea [--config /path/to/app.ini] migrate"`, current, expected)
+	}
+	return nil
+}