Fix MySQL connection handling: socket detection, timeouts, localhost vs remote

internal/database/mysql.go

@@ -4,9 +4,11 @@ import (
 	"context"
 	"database/sql"
 	"fmt"
+	"os"
 	"os/exec"
 	"strconv"
 	"strings"
+	"time"
 
 	"dbbackup/internal/config"
 	"dbbackup/internal/logger"
@@ -43,10 +45,10 @@ func (m *MySQL) Connect(ctx context.Context) error {
 	// Configure connection pool
 	db.SetMaxOpenConns(10)
 	db.SetMaxIdleConns(5)
-	db.SetConnMaxLifetime(0)
+	db.SetConnMaxLifetime(time.Hour) // Close connections after 1 hour
 
-	// Test connection
-	timeoutCtx, cancel := buildTimeout(ctx, 0)
+	// Test connection with proper timeout
+	timeoutCtx, cancel := context.WithTimeout(ctx, 30*time.Second)
 	defer cancel()
 
 	if err := db.PingContext(timeoutCtx); err != nil {
@@ -237,10 +239,16 @@ func (m *MySQL) GetTableRowCount(ctx context.Context, database, table string) (i
 func (m *MySQL) BuildBackupCommand(database, outputFile string, options BackupOptions) []string {
 	cmd := []string{"mysqldump"}
 
-	// Connection parameters
-	cmd = append(cmd, "-h", m.cfg.Host)
-	cmd = append(cmd, "-P", strconv.Itoa(m.cfg.Port))
-	cmd = append(cmd, "-u", m.cfg.User)
+	// Connection parameters - handle localhost vs remote differently
+	if m.cfg.Host == "" || m.cfg.Host == "localhost" {
+		// For localhost, use socket connection (don't specify host/port)
+		cmd = append(cmd, "-u", m.cfg.User)
+	} else {
+		// For remote hosts, use TCP/IP
+		cmd = append(cmd, "-h", m.cfg.Host)
+		cmd = append(cmd, "-P", strconv.Itoa(m.cfg.Port))
+		cmd = append(cmd, "-u", m.cfg.User)
+	}
 
 	if m.cfg.Password != "" {
 		cmd = append(cmd, "-p"+m.cfg.Password)
@@ -291,10 +299,16 @@ func (m *MySQL) BuildBackupCommand(database, outputFile string, options BackupOp
 func (m *MySQL) BuildRestoreCommand(database, inputFile string, options RestoreOptions) []string {
 	cmd := []string{"mysql"}
 
-	// Connection parameters
-	cmd = append(cmd, "-h", m.cfg.Host)
-	cmd = append(cmd, "-P", strconv.Itoa(m.cfg.Port))
-	cmd = append(cmd, "-u", m.cfg.User)
+	// Connection parameters - handle localhost vs remote differently
+	if m.cfg.Host == "" || m.cfg.Host == "localhost" {
+		// For localhost, use socket connection (don't specify host/port)
+		cmd = append(cmd, "-u", m.cfg.User)
+	} else {
+		// For remote hosts, use TCP/IP
+		cmd = append(cmd, "-h", m.cfg.Host)
+		cmd = append(cmd, "-P", strconv.Itoa(m.cfg.Port))
+		cmd = append(cmd, "-u", m.cfg.User)
+	}
 
 	if m.cfg.Password != "" {
 		cmd = append(cmd, "-p"+m.cfg.Password)
@@ -364,27 +378,71 @@ func (m *MySQL) buildDSN() string {
 
 	dsn += "@"
 
-	if m.cfg.Host != "" && m.cfg.Host != "localhost" {
+	// Handle localhost with Unix socket vs TCP/IP
+	if m.cfg.Host == "" || m.cfg.Host == "localhost" {
+		// Try common socket paths for localhost connections
+		socketPaths := []string{
+			"/run/mysqld/mysqld.sock",
+			"/var/run/mysqld/mysqld.sock",
+			"/tmp/mysql.sock",
+			"/var/lib/mysql/mysql.sock",
+		}
+		
+		// Use the first available socket path, fallback to TCP if none found
+		socketFound := false
+		for _, socketPath := range socketPaths {
+			if _, err := os.Stat(socketPath); err == nil {
+				dsn += "unix(" + socketPath + ")"
+				socketFound = true
+				break
+			}
+		}
+		
+		// If no socket found, use TCP localhost
+		if !socketFound {
+			dsn += "tcp(localhost:" + strconv.Itoa(m.cfg.Port) + ")"
+		}
+	} else {
+		// Use TCP/IP for remote connections
 		dsn += "tcp(" + m.cfg.Host + ":" + strconv.Itoa(m.cfg.Port) + ")"
 	}
 
-	dsn += "/" + m.cfg.Database
+	// Add database if specified
+	if m.cfg.Database != "" {
+		dsn += "/" + m.cfg.Database
+	} else {
+		dsn += "/"
+	}
 
 	// Add connection parameters
 	params := []string{}
 
-	if !m.cfg.Insecure {
-		switch strings.ToLower(m.cfg.SSLMode) {
+	// Add timeout parameters
+	params = append(params, "timeout=30s")
+	params = append(params, "readTimeout=30s")
+	params = append(params, "writeTimeout=30s")
+
+	// SSL configuration
+	if m.cfg.Insecure {
+		params = append(params, "tls=false")
+	} else if mode := strings.ToLower(m.cfg.SSLMode); mode != "" {
+		switch mode {
 		case "require", "required":
 			params = append(params, "tls=true")
 		case "verify-ca", "verify-full", "verify-identity":
 			params = append(params, "tls=preferred")
+		case "disable", "disabled":
+			params = append(params, "tls=false")
+		default:
+			// Default to preferred for unknown SSL modes
+			params = append(params, "tls=preferred")
 		}
 	}
 
-	// Add charset
+	// Add charset and other connection parameters
 	params = append(params, "charset=utf8mb4")
 	params = append(params, "parseTime=true")
+	params = append(params, "loc=Local")
 
 	if len(params) > 0 {
 		dsn += "?" + strings.Join(params, "&")