kra-new/internal/data/initialization_lock.go

65 lines
2.0 KiB
Go

package data
import (
"context"
"crypto/sha256"
"database/sql"
"encoding/hex"
"fmt"
"time"
configpkg "kra/internal/config"
"gorm.io/gorm"
)
// acquireInitializationLock serializes first-install work across backend Pods.
// The Kubernetes deployment uses MySQL, whose named lock is connection-scoped
// and therefore remains held while the candidate database is migrated and seeded.
func acquireInitializationLock(ctx context.Context, db *gorm.DB, database *configpkg.Database) (func(), error) {
if normalizedDriver(database.Driver) != "mysql" {
return func() {}, nil
}
sqlDB, err := db.DB()
if err != nil {
return nil, fmt.Errorf("open initialization lock connection: %w", err)
}
conn, err := sqlDB.Conn(ctx)
if err != nil {
return nil, fmt.Errorf("reserve initialization lock connection: %w", err)
}
lockName := initializationLockName(database)
var acquired sql.NullInt64
if err := conn.QueryRowContext(ctx, "SELECT GET_LOCK(?, ?)", lockName, 60).Scan(&acquired); err != nil {
_ = conn.Close()
return nil, fmt.Errorf("acquire database initialization lock: %w", err)
}
if !acquired.Valid || acquired.Int64 != 1 {
_ = conn.Close()
return nil, fmt.Errorf("database initialization lock is busy")
}
return func() {
releaseCtx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
_, _ = conn.ExecContext(releaseCtx, "SELECT RELEASE_LOCK(?)", lockName)
cancel()
_ = conn.Close()
}, nil
}
func initializationLockName(database *configpkg.Database) string {
identity := fmt.Sprintf("%s\x00%s\x00%s\x00%s", database.Driver, database.Host, database.Port, database.Name)
sum := sha256.Sum256([]byte(identity))
return "kra-init-" + hex.EncodeToString(sum[:])[:48]
}
func persistedDatabaseConfigured(runtime *configpkg.Store) bool {
if runtime == nil || runtime.ConfigPath() == "" {
return false
}
persisted, err := configpkg.Load(runtime.ConfigPath())
if err != nil || persisted == nil || persisted.Data == nil {
return false
}
return databaseConnectionConfigured(persisted.Data.Database)
}