missing file

Signed-off-by: Tim Vaillancourt <[email protected]>

go/mysql/server_info.go

@@ -0,0 +1,46 @@
+/*
+   Copyright 2023 GitHub Inc.
+         See https://github.com/github/gh-ost/blob/master/LICENSE
+*/
+
+package mysql
+
+import gosql "database/sql"
+
+// ServerInfo represents the online config of a MySQL server.
+type ServerInfo struct {
+	Version         string
+	VersionComment  string
+	Hostname        string
+	Port            gosql.NullInt64
+	BinlogFormat    string
+	BinlogRowImage  string
+	LogBin          bool
+	LogSlaveUpdates bool
+	SQLMode         string
+	TimeZone        string
+
+	// @@global.extra_port is Percona/MariaDB-only
+	ExtraPort gosql.NullInt64
+}
+
+// GetServerInfo returns a ServerInfo struct representing
+// the online config of a MySQL server.
+func GetServerInfo(db *gosql.DB) (*ServerInfo, error) {
+	var info ServerInfo
+	query := `select /* gh-ost */ @@global.version, @@global.version_comment, @@global.hostname,
+		@@global.port, @@global.binlog_format, @@global.binlog_row_image, @@global.log_bin,
+		@@global.log_slave_updates, @@global.sql_mode, @@global.time_zone`
+	if err := db.QueryRow(query).Scan(&info.Version, &info.VersionComment, &info.Hostname,
+		&info.Port, &info.BinlogFormat, &info.BinlogRowImage, &info.LogBin,
+		&info.LogSlaveUpdates, &info.SQLMode, &info.TimeZone,
+	); err != nil {
+		return nil, err
+	}
+
+	extraPortQuery := `select @@global.extra_port`
+	// swallow possible error. not all servers support extra_port
+	_ = db.QueryRow(extraPortQuery).Scan(&info.ExtraPort)
+
+	return &info, nil
+}