grafana/pkg/services/store/entity/migrations/migrator.go

package migrations

import (
	"context"
	"fmt"

	"github.com/grafana/grafana/pkg/infra/db"
	"github.com/grafana/grafana/pkg/services/featuremgmt"
	"github.com/grafana/grafana/pkg/services/sqlstore"
	"github.com/grafana/grafana/pkg/services/sqlstore/migrator"
	"github.com/grafana/grafana/pkg/services/sqlstore/session"
	"github.com/grafana/grafana/pkg/setting"
)

func MigrateEntityStore(xdb db.DB, features featuremgmt.FeatureToggles) error {
	// Skip if feature flag is not enabled
	if !features.IsEnabled(featuremgmt.FlagEntityStore) {
		return nil
	}

	// Migrations depend on upstream xorm implementations
	sql, ok := xdb.(*sqlstore.SQLStore)
	if !ok {
		return nil
	}

	// !!! This should not run in production!
	// The object store SQL schema is still in active development and this
	// will only be called when the feature toggle is enabled
	// this check should not be necessary, but is added as an extra check
	if setting.Env == setting.Prod {
		return nil
	}

	marker := "Initialize entity tables (v0)" // changing this key wipe+rewrite everything
	mg := migrator.NewScopedMigrator(sql.GetEngine(), sql.Cfg, "entity")
	mg.AddCreateMigration()
	mg.AddMigration(marker, &migrator.RawSQLMigration{})
	initEntityTables(mg)

	// While this feature is under development, we can completly wipe and recreate
	// The initial plan is to keep the source of truth in existing SQL tables, and mirrot it
	// to a kubernetes model.  Once the kubernetes model needs to be preserved,
	// this code should be removed
	log, err := mg.GetMigrationLog()
	if err != nil {
		return err
	}
	_, found := log[marker]
	if !found && len(log) > 0 {
		// Remove the migration log (and potential other orphan tables)
		tables := []string{"entity_migration_log"}

		ctx := context.Background()
		err = sql.GetSqlxSession().WithTransaction(ctx, func(tx *session.SessionTx) error {
			for _, t := range tables {
				_, err := tx.Exec(ctx, fmt.Sprintf("DROP TABLE IF EXISTS %s", t))
				if err != nil {
					return err
				}
			}
			return nil
		})
		if err != nil {
			return err
		}
	}

	return mg.Start(
		features.IsEnabled(featuremgmt.FlagMigrationLocking),
		sql.GetMigrationLockAttemptTimeout())
}