Files
dbbackup/internal/database/mysql.go

464 lines
12 KiB
Go

package database
import (
"context"
"database/sql"
"fmt"
"os"
"os/exec"
"strconv"
"strings"
"time"
"dbbackup/internal/config"
"dbbackup/internal/logger"
)
// MySQL implements Database interface for MySQL
type MySQL struct {
baseDatabase
}
// NewMySQL creates a new MySQL database instance
func NewMySQL(cfg *config.Config, log logger.Logger) *MySQL {
return &MySQL{
baseDatabase: baseDatabase{
cfg: cfg,
log: log,
},
}
}
// Connect establishes a connection to MySQL
func (m *MySQL) Connect(ctx context.Context) error {
// Build MySQL DSN
dsn := m.buildDSN()
m.dsn = dsn
m.log.Debug("Connecting to MySQL", "dsn", sanitizeMySQLDSN(dsn))
db, err := sql.Open("mysql", dsn)
if err != nil {
return fmt.Errorf("failed to open MySQL connection: %w", err)
}
// Configure connection pool
db.SetMaxOpenConns(10)
db.SetMaxIdleConns(5)
db.SetConnMaxLifetime(time.Hour) // Close connections after 1 hour
// Test connection with proper timeout
timeoutCtx, cancel := context.WithTimeout(ctx, 30*time.Second)
defer cancel()
if err := db.PingContext(timeoutCtx); err != nil {
db.Close()
return fmt.Errorf("failed to ping MySQL: %w", err)
}
m.db = db
m.log.Info("Connected to MySQL successfully")
return nil
}
// ListDatabases returns list of databases (excluding system databases)
func (m *MySQL) ListDatabases(ctx context.Context) ([]string, error) {
if m.db == nil {
return nil, fmt.Errorf("not connected to database")
}
query := `SHOW DATABASES`
rows, err := m.db.QueryContext(ctx, query)
if err != nil {
return nil, fmt.Errorf("failed to query databases: %w", err)
}
defer rows.Close()
var databases []string
systemDbs := map[string]bool{
"information_schema": true,
"performance_schema": true,
"mysql": true,
"sys": true,
}
for rows.Next() {
var name string
if err := rows.Scan(&name); err != nil {
return nil, fmt.Errorf("failed to scan database name: %w", err)
}
// Skip system databases
if !systemDbs[name] {
databases = append(databases, name)
}
}
return databases, rows.Err()
}
// ListTables returns list of tables in a database
func (m *MySQL) ListTables(ctx context.Context, database string) ([]string, error) {
if m.db == nil {
return nil, fmt.Errorf("not connected to database")
}
query := `SELECT table_name FROM information_schema.tables
WHERE table_schema = ? AND table_type = 'BASE TABLE'
ORDER BY table_name`
rows, err := m.db.QueryContext(ctx, query, database)
if err != nil {
return nil, fmt.Errorf("failed to query tables: %w", err)
}
defer rows.Close()
var tables []string
for rows.Next() {
var name string
if err := rows.Scan(&name); err != nil {
return nil, fmt.Errorf("failed to scan table name: %w", err)
}
tables = append(tables, name)
}
return tables, rows.Err()
}
// CreateDatabase creates a new database
func (m *MySQL) CreateDatabase(ctx context.Context, name string) error {
if m.db == nil {
return fmt.Errorf("not connected to database")
}
query := fmt.Sprintf("CREATE DATABASE IF NOT EXISTS `%s`", name)
_, err := m.db.ExecContext(ctx, query)
if err != nil {
return fmt.Errorf("failed to create database %s: %w", name, err)
}
m.log.Info("Created database", "name", name)
return nil
}
// DropDatabase drops a database
func (m *MySQL) DropDatabase(ctx context.Context, name string) error {
if m.db == nil {
return fmt.Errorf("not connected to database")
}
query := fmt.Sprintf("DROP DATABASE IF EXISTS `%s`", name)
_, err := m.db.ExecContext(ctx, query)
if err != nil {
return fmt.Errorf("failed to drop database %s: %w", name, err)
}
m.log.Info("Dropped database", "name", name)
return nil
}
// DatabaseExists checks if a database exists
func (m *MySQL) DatabaseExists(ctx context.Context, name string) (bool, error) {
if m.db == nil {
return false, fmt.Errorf("not connected to database")
}
query := `SELECT SCHEMA_NAME FROM information_schema.SCHEMATA WHERE SCHEMA_NAME = ?`
var dbName string
err := m.db.QueryRowContext(ctx, query, name).Scan(&dbName)
if err == sql.ErrNoRows {
return false, nil
}
if err != nil {
return false, fmt.Errorf("failed to check database existence: %w", err)
}
return true, nil
}
// GetVersion returns MySQL version
func (m *MySQL) GetVersion(ctx context.Context) (string, error) {
if m.db == nil {
return "", fmt.Errorf("not connected to database")
}
var version string
err := m.db.QueryRowContext(ctx, "SELECT VERSION()").Scan(&version)
if err != nil {
return "", fmt.Errorf("failed to get version: %w", err)
}
return version, nil
}
// GetDatabaseSize returns database size in bytes
func (m *MySQL) GetDatabaseSize(ctx context.Context, database string) (int64, error) {
if m.db == nil {
return 0, fmt.Errorf("not connected to database")
}
query := `SELECT COALESCE(SUM(data_length + index_length), 0) as size_bytes
FROM information_schema.tables
WHERE table_schema = ?`
var size int64
err := m.db.QueryRowContext(ctx, query, database).Scan(&size)
if err != nil {
return 0, fmt.Errorf("failed to get database size: %w", err)
}
return size, nil
}
// GetTableRowCount returns row count for a table
func (m *MySQL) GetTableRowCount(ctx context.Context, database, table string) (int64, error) {
if m.db == nil {
return 0, fmt.Errorf("not connected to database")
}
// First try information_schema for approximate count (faster)
query := `SELECT table_rows FROM information_schema.tables
WHERE table_schema = ? AND table_name = ?`
var count int64
err := m.db.QueryRowContext(ctx, query, database, table).Scan(&count)
if err != nil || count == 0 {
// Fallback to exact count
exactQuery := fmt.Sprintf("SELECT COUNT(*) FROM `%s`.`%s`", database, table)
err = m.db.QueryRowContext(ctx, exactQuery).Scan(&count)
if err != nil {
return 0, fmt.Errorf("failed to get table row count: %w", err)
}
}
return count, nil
}
// BuildBackupCommand builds mysqldump command
func (m *MySQL) BuildBackupCommand(database, outputFile string, options BackupOptions) []string {
cmd := []string{"mysqldump"}
// 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)
}
// SSL options
if m.cfg.Insecure {
cmd = append(cmd, "--skip-ssl")
} else if mode := strings.ToLower(m.cfg.SSLMode); mode != "" {
switch mode {
case "require", "required":
cmd = append(cmd, "--ssl-mode=REQUIRED")
case "verify-ca":
cmd = append(cmd, "--ssl-mode=VERIFY_CA")
case "verify-full", "verify-identity":
cmd = append(cmd, "--ssl-mode=VERIFY_IDENTITY")
case "disable", "disabled":
cmd = append(cmd, "--skip-ssl")
}
}
// Backup options
cmd = append(cmd, "--single-transaction") // Consistent backup
cmd = append(cmd, "--routines") // Include stored procedures/functions
cmd = append(cmd, "--triggers") // Include triggers
cmd = append(cmd, "--events") // Include events
if options.SchemaOnly {
cmd = append(cmd, "--no-data")
} else if options.DataOnly {
cmd = append(cmd, "--no-create-info")
}
if options.NoOwner || options.NoPrivileges {
cmd = append(cmd, "--skip-add-drop-table")
}
// Compression (handled externally for MySQL)
// Output redirection will be handled by caller
// Database
cmd = append(cmd, database)
return cmd
}
// BuildRestoreCommand builds mysql restore command
func (m *MySQL) BuildRestoreCommand(database, inputFile string, options RestoreOptions) []string {
cmd := []string{"mysql"}
// 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)
}
// SSL options
if m.cfg.Insecure {
cmd = append(cmd, "--skip-ssl")
}
// Options
if options.SingleTransaction {
cmd = append(cmd, "--single-transaction")
}
// Database
cmd = append(cmd, database)
// Input file (will be handled via stdin redirection)
return cmd
}
// BuildSampleQuery builds SQL query for sampling data
func (m *MySQL) BuildSampleQuery(database, table string, strategy SampleStrategy) string {
switch strategy.Type {
case "ratio":
// Every Nth record using row_number (MySQL 8.0+) or modulo
return fmt.Sprintf("SELECT * FROM (SELECT *, (@row_number:=@row_number + 1) AS rn FROM %s.%s CROSS JOIN (SELECT @row_number:=0) AS t) AS numbered WHERE rn %% %d = 1",
database, table, strategy.Value)
case "percent":
// Percentage sampling using RAND()
return fmt.Sprintf("SELECT * FROM %s.%s WHERE RAND() <= %f",
database, table, float64(strategy.Value)/100.0)
case "count":
// First N records
return fmt.Sprintf("SELECT * FROM %s.%s LIMIT %d", database, table, strategy.Value)
default:
return fmt.Sprintf("SELECT * FROM %s.%s LIMIT 1000", database, table)
}
}
// ValidateBackupTools checks if required MySQL tools are available
func (m *MySQL) ValidateBackupTools() error {
tools := []string{"mysqldump", "mysql"}
for _, tool := range tools {
if _, err := exec.LookPath(tool); err != nil {
return fmt.Errorf("required tool not found: %s", tool)
}
}
return nil
}
// buildDSN constructs MySQL connection string
func (m *MySQL) buildDSN() string {
dsn := ""
if m.cfg.User != "" {
dsn += m.cfg.User
}
if m.cfg.Password != "" {
dsn += ":" + m.cfg.Password
}
dsn += "@"
// 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) + ")"
}
// Add database if specified
if m.cfg.Database != "" {
dsn += "/" + m.cfg.Database
} else {
dsn += "/"
}
// Add connection parameters
params := []string{}
// 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 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, "&")
}
return dsn
}
// sanitizeMySQLDSN removes password from DSN for logging
func sanitizeMySQLDSN(dsn string) string {
// Find password part and replace it
if idx := strings.Index(dsn, ":"); idx != -1 {
if endIdx := strings.Index(dsn[idx:], "@"); endIdx != -1 {
return dsn[:idx] + ":***" + dsn[idx+endIdx:]
}
}
return dsn
}