Small refactoring (#43)

* Changed 'Disabled' const

* Small refactoring

* A couple of methods transformed to functions

internal/mysql/cluster.go

@@ -17,10 +17,10 @@ type Cluster struct {
 	sync.Mutex
 	config       *config.Config
 	logger       *log.Logger
-	haNodes      map[string]*Node
-	cascadeNodes map[string]*Node
 	local        *Node
 	dcs          dcs.DCS
+	haNodes      map[string]*Node
+	cascadeNodes map[string]*Node
 }
 
 func (c *Cluster) IsHAHost(hostname string) bool {

internal/mysql/data.go

@@ -41,8 +41,8 @@ type NodeConfiguration struct {
 }
 
 type ResetupStatus struct {
-	Status     bool
 	UpdateTime time.Time
+	Status     bool
 }
 
 type replicationSettings struct {

internal/mysql/node.go

@@ -31,9 +31,9 @@ import (
 type Node struct {
 	config  *config.Config
 	logger  *log.Logger
-	host    string
 	db      *sqlx.DB
 	version *Version
+	host    string
 }
 
 var (
@@ -147,8 +147,8 @@ func (n *Node) getQuery(name string) string {
 func (n *Node) traceQuery(query string, arg interface{}, result interface{}, err error) {
 	query = queryOnliner.ReplaceAllString(query, " ")
 	msg := fmt.Sprintf("node %s running query '%s' with args %#v, result: %#v, error: %v", n.host, query, arg, result, err)
-	msg = strings.Replace(msg, n.config.MySQL.Password, "********", -1)
-	msg = strings.Replace(msg, n.config.MySQL.ReplicationPassword, "********", -1)
+	msg = strings.ReplaceAll(msg, n.config.MySQL.Password, "********")
+	msg = strings.ReplaceAll(msg, n.config.MySQL.ReplicationPassword, "********")
 	n.logger.Debug(msg)
 }
 
@@ -158,15 +158,9 @@ func (n *Node) queryRow(queryName string, arg interface{}, result interface{}) e
 }
 
 func (n *Node) queryRowWithTimeout(queryName string, arg interface{}, result interface{}, timeout time.Duration) error {
-	if arg == nil {
-		arg = struct{}{}
-	}
-	query := n.getQuery(queryName)
-	ctx, cancel := context.WithTimeout(context.Background(), timeout)
-	defer cancel()
-	rows, err := n.db.NamedQueryContext(ctx, query, arg)
-	if err == nil {
-		defer func() { _ = rows.Close() }()
+	return n.processQuery(queryName, arg, func(rows *sqlx.Rows) error {
+		var err error
+
 		if rows.Next() {
 			err = rows.StructScan(result)
 		} else {
@@ -175,32 +169,45 @@ func (n *Node) queryRowWithTimeout(queryName string, arg interface{}, result int
 				err = sql.ErrNoRows
 			}
 		}
-	}
-	n.traceQuery(query, arg, result, err)
-	return err
+
+		return err
+	}, timeout)
 }
 
 // nolint: unparam
 func (n *Node) queryRows(queryName string, arg interface{}, scanner func(*sqlx.Rows) error) error {
+	return n.processQuery(queryName, arg, func(rows *sqlx.Rows) error {
+		var err error
+
+		for rows.Next() {
+			err = scanner(rows)
+			if err != nil {
+				break
+			}
+		}
+
+		return err
+	}, n.config.DBTimeout)
+}
+
+func (n *Node) processQuery(queryName string, arg interface{}, rowsProcessor func(*sqlx.Rows) error, timeout time.Duration) error {
 	if arg == nil {
 		arg = struct{}{}
 	}
-	query := n.getQuery(queryName)
-	ctx, cancel := context.WithTimeout(context.Background(), n.config.DBTimeout)
+
+	ctx, cancel := context.WithTimeout(context.Background(), timeout)
 	defer cancel()
+
+	query := n.getQuery(queryName)
 	rows, err := n.db.NamedQueryContext(ctx, query, arg)
 	n.traceQuery(query, arg, rows, err)
 	if err != nil {
 		return err
 	}
+
 	defer func() { _ = rows.Close() }()
-	for rows.Next() {
-		err = scanner(rows)
-		if err != nil {
-			break
-		}
-	}
-	return err
+
+	return rowsProcessor(rows)
 }
 
 // nolint: unparam
@@ -265,8 +272,8 @@ func (n *Node) getRunningQueryIds(excludeUsers []string, timeout time.Duration)
 type schemaname string
 
 func escape(s string) string {
-	s = strings.Replace(s, `\`, `\\`, -1)
-	s = strings.Replace(s, `'`, `\'`, -1)
+	s = strings.ReplaceAll(s, `\`, `\\`)
+	s = strings.ReplaceAll(s, `'`, `\'`)
 	return s
 }
 
@@ -372,18 +379,6 @@ func (n *Node) GetDiskUsage() (used uint64, total uint64, err error) {
 	return
 }
 
-func (n *Node) isTestFileSystemReadonly(f string) (bool, error) {
-	data, err := os.ReadFile(f)
-	if err != nil {
-		return false, err
-	}
-	value, err := strconv.ParseBool(strings.TrimSpace(string(data)))
-	if err != nil {
-		return false, fmt.Errorf("error while parce test file: %s", err)
-	}
-	return value, nil
-}
-
 func getFlagsFromProcMounts(file, filesystem string) (string, error) {
 	for _, line := range strings.Split(file, "\n") {
 		components := strings.Split(line, " ")
@@ -407,7 +402,7 @@ func getFlagsFromProcMounts(file, filesystem string) (string, error) {
 
 func (n *Node) IsFileSystemReadonly() (bool, error) {
 	if n.config.TestFilesystemReadonlyFile != "" {
-		return n.isTestFileSystemReadonly(n.config.TestFilesystemReadonlyFile)
+		return isTestFileSystemReadonly(n.config.TestFilesystemReadonlyFile)
 	}
 	if !n.IsLocal() {
 		return false, ErrNotLocalNode
@@ -431,6 +426,18 @@ func (n *Node) IsFileSystemReadonly() (bool, error) {
 	}
 }
 
+func isTestFileSystemReadonly(f string) (bool, error) {
+	data, err := os.ReadFile(f)
+	if err != nil {
+		return false, err
+	}
+	value, err := strconv.ParseBool(strings.TrimSpace(string(data)))
+	if err != nil {
+		return false, fmt.Errorf("error while parce test file: %s", err)
+	}
+	return value, nil
+}
+
 func (n *Node) GetDaemonStartTime() (time.Time, error) {
 	if !n.IsLocal() {
 		return time.Time{}, ErrNotLocalNode
@@ -900,7 +907,7 @@ func (n *Node) UpdateExternalCAFile() error {
 		}
 		if data != string(oldDataByte) {
 			n.logger.Infof("saving new CA file to %s", fileName)
-			err := n.SaveCAFile(data, fileName)
+			err := SaveCAFile(data, fileName)
 			if err != nil {
 				return err
 			}
@@ -920,7 +927,7 @@ func (n *Node) UpdateExternalCAFile() error {
 	return nil
 }
 
-func (n *Node) SaveCAFile(data string, path string) error {
+func SaveCAFile(data string, path string) error {
 	rootCertPool := x509.NewCertPool()
 	byteData := []byte(data)
 	if ok := rootCertPool.AppendCertsFromPEM(byteData); !ok {

internal/mysql/util.go

@@ -13,8 +13,10 @@ var dubiousErrorNumbers = []uint16{
 	1698, // Symbol: ER_ACCESS_DENIED_NO_PASSWORD_ERROR; SQLSTATE: 28000
 }
 
-const channelDoesNotExists = 3074 // Symbol: ER_REPLICA_CHANNEL_DOES_NOT_EXIST; SQLSTATE: HY000
-const tableDoesNotExists = 1146   // Symbol: ER_NO_SUCH_TABLE; SQLSTATE: 42S02
+const (
+	channelDoesNotExists = 3074 // Symbol: ER_REPLICA_CHANNEL_DOES_NOT_EXIST; SQLSTATE: HY000
+	tableDoesNotExists   = 1146 // Symbol: ER_NO_SUCH_TABLE; SQLSTATE: 42S02
+)
 
 // IsErrorDubious check that error may be caused by misconfiguration, mysync/scripts bugs
 // and not related to MySQL/network failure

internal/util/consts.go

@@ -3,6 +3,6 @@ package util
 type ExternalReplicationType string
 
 const (
-	Disabled              ExternalReplicationType = ""
+	Disabled              ExternalReplicationType = "off"
 	MyExternalReplication ExternalReplicationType = "external"
 )