feat: implement initial GoDump backup service with management web UI and MySQL support

backup/mysql.go

@@ -0,0 +1,87 @@
+package backup
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"time"
+
+	"godump/config"
+	"godump/logger"
+)
+
+func backupDatabase(cfg config.InstanceConfig, dbName string) (int64, error) {
+	// Create backup directory for this database
+	targetDir := filepath.Join(cfg.BackupDir, dbName)
+	if err := os.MkdirAll(targetDir, 0755); err != nil {
+		return 0, fmt.Errorf("failed to create backup directory %s: %w", targetDir, err)
+	}
+
+	// Filename format: instancename_dbname_2006-01-02_15-04-05.sql.gz
+	timestamp := time.Now().Format("2006-01-02_15-04-05")
+	filename := fmt.Sprintf("%s_%s_%s.sql.gz", cfg.Name, dbName, timestamp)
+	targetFile := filepath.Join(targetDir, filename)
+
+	f, err := os.Create(targetFile)
+	if err != nil {
+		return 0, fmt.Errorf("failed to create backup file %s: %w", targetFile, err)
+	}
+	defer f.Close()
+
+	// Using sh -c allows us to pipe mysqldump output to gzip easily.
+	// Since we are taking dbName from INFORMATION_SCHEMA, we should still be careful with quotes,
+	// but mysqldump arguments can be passed via command directly, and we can pipe in go, or use sh.
+	// Piping in Go is safer.
+
+	cmdDump := exec.Command("mysqldump",
+		fmt.Sprintf("-h%s", cfg.Host),
+		fmt.Sprintf("-P%d", cfg.Port),
+		fmt.Sprintf("-u%s", cfg.User),
+		fmt.Sprintf("-p%s", cfg.Password),
+		"--single-transaction",
+		"--routines",
+		"--triggers",
+		dbName,
+	)
+
+	cmdGzip := exec.Command("gzip", "-c")
+
+	// Create pipe between mysqldump and gzip
+	dumpOut, err := cmdDump.StdoutPipe()
+	if err != nil {
+		return 0, fmt.Errorf("failed to create dump stdout pipe: %w", err)
+	}
+	cmdDump.Stderr = os.Stderr // or capture it
+
+	cmdGzip.Stdin = dumpOut
+	cmdGzip.Stdout = f
+	cmdGzip.Stderr = os.Stderr
+
+	if err := cmdDump.Start(); err != nil {
+		return 0, fmt.Errorf("failed to start mysqldump: %w", err)
+	}
+
+	if err := cmdGzip.Start(); err != nil {
+		cmdDump.Process.Kill()
+		return 0, fmt.Errorf("failed to start gzip: %w", err)
+	}
+
+	if err := cmdDump.Wait(); err != nil {
+		cmdGzip.Process.Kill()
+		return 0, fmt.Errorf("mysqldump failed: %w", err)
+	}
+
+	if err := cmdGzip.Wait(); err != nil {
+		return 0, fmt.Errorf("gzip failed: %w", err)
+	}
+
+	// Get file size
+	stat, err := f.Stat()
+	if err != nil {
+		logger.Warn(cfg.Name, "Could not stat file %s to get size: %v", targetFile, err)
+		return 0, nil
+	}
+
+	return stat.Size(), nil
+}