Draft: add mysql validations

flow/connectors/mysql/validate.go

@@ -1,14 +1,172 @@
 package connmysql
 
+
 import (
 	"context"
+	"database/sql"
 	"errors"
+	"fmt"
+	"strings"
 
 	"github.com/go-mysql-org/go-mysql/mysql"
+	_ "github.com/go-sql-driver/mysql"
 
+	"github.com/PeerDB-io/peerdb/flow/connectors/utils"
 	"github.com/PeerDB-io/peerdb/flow/generated/protos"
+	"github.com/PeerDB-io/peerdb/flow/shared"
 )
 
+type MySQLConnector struct {
+	conn *sql.DB
+	config *MySQLConfig
+}
+
+func (c *MySQLConnector) CheckSourceTables(ctx context.Context, tableNames []*utils.SchemaTable) error {
+	if c.conn == nil {
+		return errors.New("check tables: conn is nil")
+	}
+
+	for _, parsedTable := range tableNames {
+		query := fmt.Sprintf("SELECT 1 FROM `%s`.`%s` LIMIT 1", parsedTable.Schema, parsedTable.Table)
+		_, err := c.conn.QueryContext(ctx, query)
+		if err != nil {
+			return fmt.Errorf("error checking table %s.%s: %v", parsedTable.Schema, parsedTable.Table, err)
+		}
+	}
+	return nil
+}
+
+func (c *MySQLConnector) CheckReplicationPermissions(ctx context.Context) error {
+	if c.conn == nil {
+		return errors.New("check replication permissions: conn is nil")
+	}
+
+	var replicationPrivilege string
+	err := c.conn.QueryRowContext(ctx, "SHOW GRANTS FOR CURRENT_USER()").Scan(&replicationPrivilege)
+	if err != nil {
+		return fmt.Errorf("failed to check replication privileges: %v", err)
+	}
+
+	if !strings.Contains(replicationPrivilege, "REPLICATION SLAVE") && !strings.Contains(replicationPrivilege, "REPLICATION CLIENT") {
+		return errors.New("MySQL user does not have replication privileges")
+	}
+
+	return nil
+}
+
+func (c *MySQLConnector) CheckReplicationConnectivity(ctx context.Context) error {
+	if c.conn == nil {
+		return errors.New("check replication connectivity: conn is nil")
+	}
+
+	var masterLogFile string
+	var masterLogPos int
+
+	err := c.conn.QueryRowContext(ctx, "SHOW MASTER STATUS").Scan(&masterLogFile, &masterLogPos)
+	if err != nil {
+		// Handle case where SHOW MASTER STATUS returns no rows (binary logging disabled)
+		if errors.Is(err, sql.ErrNoRows) {
+			return errors.New("binary logging is disabled on this MySQL server")
+		}
+		return fmt.Errorf("failed to check replication status: %v", err)
+	}
+
+	// Additional validation: Check if the values are valid
+	if masterLogFile == "" || masterLogPos <= 0 {
+		return errors.New("invalid replication status: missing log file or position")
+	}
+
+	return nil
+}
+
+func (c *MySQLConnector) CheckBinlogSettings(ctx context.Context) error {
+	if c.conn == nil {
+		return errors.New("check binlog settings: conn is nil")
+	}
+
+	// Check binlog_expire_logs_seconds
+	var expireSeconds int
+	err := c.conn.QueryRowContext(ctx, "SELECT @@binlog_expire_logs_seconds").Scan(&expireSeconds)
+	if err != nil {
+		return fmt.Errorf("failed to retrieve binlog_expire_logs_seconds: %v", err)
+	}
+	if expireSeconds <= 86400 {
+		return errors.New("binlog_expire_logs_seconds is too low. Must be greater than 1 day")
+	}
+
+	// Check binlog_format
+	var binlogFormat string
+	err = c.conn.QueryRowContext(ctx, "SELECT @@binlog_format").Scan(&binlogFormat)
+	if err != nil {
+		return fmt.Errorf("failed to retrieve binlog_format: %v", err)
+	}
+	if binlogFormat != "ROW" {
+		return errors.New("binlog_format must be set to 'ROW'")
+	}
+
+	// Check binlog_row_metadata
+	var binlogRowMetadata string
+	err = c.conn.QueryRowContext(ctx, "SELECT @@binlog_row_metadata").Scan(&binlogRowMetadata)
+	if err != nil {
+		return fmt.Errorf("failed to retrieve binlog_row_metadata: %v", err)
+	}
+	if binlogRowMetadata != "FULL" {
+		return errors.New("binlog_row_metadata must be set to 'FULL' for column exclusion support")
+	}
+
+	// Check binlog_row_image
+	var binlogRowImage string
+	err = c.conn.QueryRowContext(ctx, "SELECT @@binlog_row_image").Scan(&binlogRowImage)
+	if err != nil {
+		return fmt.Errorf("failed to retrieve binlog_row_image: %v", err)
+	}
+	if binlogRowImage != "FULL" {
+		return errors.New("binlog_row_image must be set to 'FULL' (equivalent to PostgreSQL's REPLICA IDENTITY FULL)")
+	}
+
+	// Check binlog_row_value_options
+	var binlogRowValueOptions string
+	err = c.conn.QueryRowContext(ctx, "SELECT @@binlog_row_value_options").Scan(&binlogRowValueOptions)
+	if err != nil {
+		return fmt.Errorf("failed to retrieve binlog_row_value_options: %v", err)
+	}
+	if binlogRowValueOptions != "" {
+		return errors.New("binlog_row_value_options must be disabled to prevent JSON change deltas")
+	}
+
+	return nil
+}
+
+func (c *MySQLConnector) ValidateMirrorSource(ctx context.Context, cfg *protos.FlowConnectionConfigs) error {
+	sourceTables := make([]*utils.SchemaTable, 0, len(cfg.TableMappings))
+	for _, tableMapping := range cfg.TableMappings {
+		parsedTable, parseErr := utils.ParseSchemaTable(tableMapping.SourceTableIdentifier)
+		if parseErr != nil {
+			return fmt.Errorf("invalid source table identifier: %s", parseErr)
+		}
+		sourceTables = append(sourceTables, parsedTable)
+	}
+
+	if err := c.CheckReplicationConnectivity(ctx); err != nil {
+		return fmt.Errorf("unable to establish replication connectivity: %v", err)
+	}
+
+	if err := c.CheckReplicationPermissions(ctx); err != nil {
+		return fmt.Errorf("failed to check replication permissions: %v", err)
+	}
+
+	if err := c.CheckSourceTables(ctx, sourceTables); err != nil {
+		return fmt.Errorf("provided source tables invalidated: %v", err)
+	}
+
+	if err := c.CheckBinlogSettings(ctx); err != nil {
+		return fmt.Errorf("binlog configuration error: %v", err)
+	}
+
+	return nil
+}
+
+
 func (c *MySqlConnector) ValidateCheck(ctx context.Context) error {
 	if _, err := c.Execute(ctx, "select @@gtid_mode"); err != nil {
 		var mErr *mysql.MyError
@@ -24,6 +182,19 @@ func (c *MySqlConnector) ValidateCheck(ctx context.Context) error {
 	} else if c.config.Flavor == protos.MySqlFlavor_MYSQL_UNKNOWN {
 		return errors.New("flavor is set to unknown")
 	}
+
+	if err := c.CheckReplicationConnectivity(ctx); err != nil {
+		return fmt.Errorf("unable to establish replication connectivity: %v", err)
+	}
+
+	if err := c.CheckReplicationPermissions(ctx); err != nil {
+		return fmt.Errorf("failed to check replication permissions: %v", err)
+	}
+
+	if err := c.CheckBinlogSettings(ctx); err != nil {
+		return fmt.Errorf("binlog configuration error: %v", err)
+	}
+
 	return nil
 }