Function ValidateConnection

go/base/utils.go:64–104

(db *gosql.DB, connectionConfig *mysql.ConnectionConfig, migrationContext *MigrationContext, name string)

}

func ValidateConnection(db *gosql.DB, connectionConfig *mysql.ConnectionConfig, migrationContext *MigrationContext, name string) (string, error) {
	versionQuery := `select @@global.version`

	var version string
	if err := db.QueryRow(versionQuery).Scan(&version); err != nil {
		return "", err
	}

	if migrationContext.SkipPortValidation {
		return version, nil
	}

	var extraPort int

	extraPortQuery := `select @@global.extra_port`
	if err := db.QueryRow(extraPortQuery).Scan(&extraPort); err != nil { //nolint:staticcheck
		// swallow this error. not all servers support extra_port
	}

	// AliyunRDS set users port to "NULL", replace it by gh-ost param
	// GCP set users port to "NULL", replace it by gh-ost param
	// Azure MySQL set users port to a different value by design, replace it by gh-ost para
	var port int
	if migrationContext.AliyunRDS || migrationContext.GoogleCloudPlatform || migrationContext.AzureMySQL {
		port = connectionConfig.Key.Port
	} else {
		portQuery := `select @@global.port`
		if err := db.QueryRow(portQuery).Scan(&port); err != nil {
			return "", err
		}
	}

	if connectionConfig.Key.Port == port || (extraPort > 0 && connectionConfig.Key.Port == extraPort) {
		migrationContext.Log.Infof("%s connection validated on %+v", name, connectionConfig.Key)
		return version, nil
	} else if extraPort == 0 {
		return "", fmt.Errorf("unexpected database port reported: %+v", port)
	} else {
		return "", fmt.Errorf("unexpected database port reported: %+v / extra_port: %+v", port, extraPort)
	}
}