feat: inject unified data migrations in dual writer (#114138)

* feat: draft changes for on-prem unified migration

* feat: further draft changes for on-prem unified migration

* fix: remove some tbis

* refactor: rename

* fix: another approach

* fix: background service related issues

* fix: address comments

* fix: make gen-go

* fix: background service related issues

* feat: refactor dual writer and legacy migrator

* fix: minor issues

* feat: working version in oss

* fix: wire

* fix: revert test data override

* fix: enterprise related issues

* chore: add todo

* fix: revert dual writer method

* fix: lint

* chore: logger format

* fix: reduce log level

* fix: log change

* fix: disable

* fix: address comments

* fix: return error on dual writer service

* fix: merge conflict

---------

Co-authored-by: Rafael Paulovic <rafael.paulovic@grafana.com>

pkg/registry/apis/provisioning/jobs/migrate/legacy_resources.go

@@ -14,6 +14,7 @@ import (
 	"github.com/grafana/grafana/pkg/registry/apis/provisioning/jobs/export"
 	"github.com/grafana/grafana/pkg/registry/apis/provisioning/resources"
 	"github.com/grafana/grafana/pkg/registry/apis/provisioning/resources/signature"
+	unifiedmigrations "github.com/grafana/grafana/pkg/storage/unified/migrations"
 	"github.com/grafana/grafana/pkg/storage/unified/parquet"
 	"github.com/grafana/grafana/pkg/storage/unified/resource"
 	"github.com/grafana/grafana/pkg/storage/unified/resourcepb"
@@ -29,7 +30,7 @@ type LegacyResourcesMigrator interface {
 type legacyResourcesMigrator struct {
 	repositoryResources resources.RepositoryResourcesFactory
 	parsers             resources.ParserFactory
-	legacyMigrator      legacy.LegacyMigrator
+	dashboardAccess     legacy.MigrationDashboardAccessor
 	signerFactory       signature.SignerFactory
 	clients             resources.ClientFactory
 	exportFn            export.ExportFn
@@ -38,7 +39,7 @@ type legacyResourcesMigrator struct {
 func NewLegacyResourcesMigrator(
 	repositoryResources resources.RepositoryResourcesFactory,
 	parsers resources.ParserFactory,
-	legacyMigrator legacy.LegacyMigrator,
+	dashboardAccess legacy.MigrationDashboardAccessor,
 	signerFactory signature.SignerFactory,
 	clients resources.ClientFactory,
 	exportFn export.ExportFn,
@@ -46,7 +47,7 @@ func NewLegacyResourcesMigrator(
 	return &legacyResourcesMigrator{
 		repositoryResources: repositoryResources,
 		parsers:             parsers,
-		legacyMigrator:      legacyMigrator,
+		dashboardAccess:     dashboardAccess,
 		signerFactory:       signerFactory,
 		clients:             clients,
 		exportFn:            exportFn,
@@ -94,7 +95,7 @@ func (m *legacyResourcesMigrator) Migrate(ctx context.Context, rw repository.Rea
 
 		reader := newLegacyResourceMigrator(
 			rw,
-			m.legacyMigrator,
+			m.dashboardAccess,
 			parser,
 			repositoryResources,
 			progress,
@@ -113,21 +114,21 @@ func (m *legacyResourcesMigrator) Migrate(ctx context.Context, rw repository.Rea
 }
 
 type legacyResourceResourceMigrator struct {
-	repo      repository.ReaderWriter
-	legacy    legacy.LegacyMigrator
-	parser    resources.Parser
-	progress  jobs.JobProgressRecorder
-	namespace string
-	kind      schema.GroupResource
-	options   provisioning.MigrateJobOptions
-	resources resources.RepositoryResources
-	signer    signature.Signer
-	history   map[string]string // UID >> file path
+	repo            repository.ReaderWriter
+	dashboardAccess legacy.MigrationDashboardAccessor
+	parser          resources.Parser
+	progress        jobs.JobProgressRecorder
+	namespace       string
+	kind            schema.GroupResource
+	options         provisioning.MigrateJobOptions
+	resources       resources.RepositoryResources
+	signer          signature.Signer
+	history         map[string]string // UID >> file path
 }
 
 func newLegacyResourceMigrator(
 	repo repository.ReaderWriter,
-	legacy legacy.LegacyMigrator,
+	dashboardAccess legacy.MigrationDashboardAccessor,
 	parser resources.Parser,
 	resources resources.RepositoryResources,
 	progress jobs.JobProgressRecorder,
@@ -141,16 +142,16 @@ func newLegacyResourceMigrator(
 		history = make(map[string]string)
 	}
 	return &legacyResourceResourceMigrator{
-		repo:      repo,
-		legacy:    legacy,
-		parser:    parser,
-		progress:  progress,
-		options:   options,
-		namespace: namespace,
-		kind:      kind,
-		resources: resources,
-		signer:    signer,
-		history:   history,
+		repo:            repo,
+		dashboardAccess: dashboardAccess,
+		parser:          parser,
+		progress:        progress,
+		options:         options,
+		namespace:       namespace,
+		kind:            kind,
+		resources:       resources,
+		signer:          signer,
+		history:         history,
 	}
 }
 
@@ -225,14 +226,21 @@ func (r *legacyResourceResourceMigrator) Write(ctx context.Context, key *resourc
 
 func (r *legacyResourceResourceMigrator) Migrate(ctx context.Context) error {
 	r.progress.SetMessage(ctx, fmt.Sprintf("migrate %s resource", r.kind.Resource))
+
+	// Create a parquet migrator with this instance as the BulkResourceWriter
+	parquetClient := parquet.NewBulkResourceWriterClient(r)
+	migrator := unifiedmigrations.ProvideUnifiedMigratorParquet(
+		r.dashboardAccess,
+		parquetClient,
+	)
+
 	opts := legacy.MigrateOptions{
 		Namespace:   r.namespace,
 		WithHistory: r.options.History,
 		Resources:   []schema.GroupResource{r.kind},
-		Store:       parquet.NewBulkResourceWriterClient(r),
 		OnlyCount:   true, // first get the count
 	}
-	stats, err := r.legacy.Migrate(ctx, opts)
+	stats, err := migrator.Migrate(ctx, opts)
 	if err != nil {
 		return fmt.Errorf("unable to count legacy items %w", err)
 	}
@@ -248,7 +256,7 @@ func (r *legacyResourceResourceMigrator) Migrate(ctx context.Context) error {
 	}
 
 	opts.OnlyCount = false // this time actually write
-	_, err = r.legacy.Migrate(ctx, opts)
+	_, err = migrator.Migrate(ctx, opts)
 	if err != nil {
 		return fmt.Errorf("migrate legacy %s: %w", r.kind.Resource, err)
 	}

pkg/registry/apis/provisioning/jobs/migrate/legacy_resources_test.go

@@ -93,8 +93,8 @@ func TestLegacyResourcesMigrator_Migrate(t *testing.T) {
 		mockRepoResourcesFactory.On("Client", mock.Anything, mock.Anything).
 			Return(mockRepoResources, nil)
 
-		mockLegacyMigrator := legacy.NewMockLegacyMigrator(t)
-		mockLegacyMigrator.On("Migrate", mock.Anything, mock.MatchedBy(func(opts legacy.MigrateOptions) bool {
+		mockDashboardAccess := legacy.NewMockMigrationDashboardAccessor(t)
+		mockDashboardAccess.On("CountResources", mock.Anything, mock.MatchedBy(func(opts legacy.MigrateOptions) bool {
 			return opts.OnlyCount && opts.Namespace == "test-namespace"
 		})).Return(&resourcepb.BulkResponse{}, errors.New("legacy migrator error"))
 
@@ -115,7 +115,7 @@ func TestLegacyResourcesMigrator_Migrate(t *testing.T) {
 		migrator := NewLegacyResourcesMigrator(
 			mockRepoResourcesFactory,
 			mockParserFactory,
-			mockLegacyMigrator,
+			mockDashboardAccess,
 			signerFactory,
 			mockClientFactory,
 			mockExportFn.Execute,
@@ -136,7 +136,7 @@ func TestLegacyResourcesMigrator_Migrate(t *testing.T) {
 
 		mockParserFactory.AssertExpectations(t)
 		mockRepoResourcesFactory.AssertExpectations(t)
-		mockLegacyMigrator.AssertExpectations(t)
+		mockDashboardAccess.AssertExpectations(t)
 		progress.AssertExpectations(t)
 		mockExportFn.AssertExpectations(t)
 		mockClientFactory.AssertExpectations(t)
@@ -308,22 +308,18 @@ func TestLegacyResourcesMigrator_Migrate(t *testing.T) {
 			History:   true,
 		}).Return(mockSigner, nil)
 
-		mockLegacyMigrator := legacy.NewMockLegacyMigrator(t)
-		mockLegacyMigrator.On("Migrate", mock.Anything, mock.MatchedBy(func(opts legacy.MigrateOptions) bool {
+		mockDashboardAccess := legacy.NewMockMigrationDashboardAccessor(t)
+		// Mock CountResources for the count phase
+		mockDashboardAccess.On("CountResources", mock.Anything, mock.MatchedBy(func(opts legacy.MigrateOptions) bool {
 			return opts.OnlyCount && opts.Namespace == "test-namespace"
-		})).Return(&resourcepb.BulkResponse{}, nil).Once() // Count phase
-		mockLegacyMigrator.On("Migrate", mock.Anything, mock.MatchedBy(func(opts legacy.MigrateOptions) bool {
+		})).Return(&resourcepb.BulkResponse{}, nil).Once()
+		// Mock MigrateDashboards for the actual migration phase (dashboards resource)
+		mockDashboardAccess.On("MigrateDashboards", mock.Anything, mock.Anything, mock.MatchedBy(func(opts legacy.MigrateOptions) bool {
 			return !opts.OnlyCount && opts.Namespace == "test-namespace"
-		})).Return(&resourcepb.BulkResponse{
-			Summary: []*resourcepb.BulkResponse_Summary{
-				{
-					Group:    "test.grafana.app",
-					Resource: "tests",
-					Count:    10,
-					History:  5,
-				},
-			},
-		}, nil).Once() // Migration phase
+		}), mock.Anything).Return(&legacy.BlobStoreInfo{
+			Count: 10,
+			Size:  5,
+		}, nil).Once()
 
 		mockClients := resources.NewMockResourceClients(t)
 		mockClientFactory := resources.NewMockClientFactory(t)
@@ -339,7 +335,7 @@ func TestLegacyResourcesMigrator_Migrate(t *testing.T) {
 		migrator := NewLegacyResourcesMigrator(
 			mockRepoResourcesFactory,
 			mockParserFactory,
-			mockLegacyMigrator,
+			mockDashboardAccess,
 			mockSignerFactory,
 			mockClientFactory,
 			mockExportFn.Execute,
@@ -362,7 +358,7 @@ func TestLegacyResourcesMigrator_Migrate(t *testing.T) {
 
 		mockParserFactory.AssertExpectations(t)
 		mockRepoResourcesFactory.AssertExpectations(t)
-		mockLegacyMigrator.AssertExpectations(t)
+		mockDashboardAccess.AssertExpectations(t)
 		mockClientFactory.AssertExpectations(t)
 		mockExportFn.AssertExpectations(t)
 		progress.AssertExpectations(t)
@@ -742,8 +738,8 @@ func TestLegacyResourceResourceMigrator_Write(t *testing.T) {
 
 func TestLegacyResourceResourceMigrator_Migrate(t *testing.T) {
 	t.Run("should fail when legacy migrate count fails", func(t *testing.T) {
-		mockLegacyMigrator := legacy.NewMockLegacyMigrator(t)
-		mockLegacyMigrator.On("Migrate", mock.Anything, mock.MatchedBy(func(opts legacy.MigrateOptions) bool {
+		mockDashboardAccess := legacy.NewMockMigrationDashboardAccessor(t)
+		mockDashboardAccess.On("CountResources", mock.Anything, mock.MatchedBy(func(opts legacy.MigrateOptions) bool {
 			return opts.OnlyCount && opts.Namespace == "test-namespace"
 		})).Return(&resourcepb.BulkResponse{}, errors.New("count error"))
 
@@ -752,7 +748,7 @@ func TestLegacyResourceResourceMigrator_Migrate(t *testing.T) {
 
 		migrator := newLegacyResourceMigrator(
 			nil,
-			mockLegacyMigrator,
+			mockDashboardAccess,
 			nil,
 			nil,
 			progress,
@@ -766,89 +762,91 @@ func TestLegacyResourceResourceMigrator_Migrate(t *testing.T) {
 		require.Error(t, err)
 		require.Contains(t, err.Error(), "unable to count legacy items")
 
-		mockLegacyMigrator.AssertExpectations(t)
+		mockDashboardAccess.AssertExpectations(t)
 		progress.AssertExpectations(t)
 	})
 
 	t.Run("should fail when legacy migrate write fails", func(t *testing.T) {
-		mockLegacyMigrator := legacy.NewMockLegacyMigrator(t)
-		mockLegacyMigrator.On("Migrate", mock.Anything, mock.MatchedBy(func(opts legacy.MigrateOptions) bool {
+		mockDashboardAccess := legacy.NewMockMigrationDashboardAccessor(t)
+		mockDashboardAccess.On("CountResources", mock.Anything, mock.MatchedBy(func(opts legacy.MigrateOptions) bool {
 			return opts.OnlyCount && opts.Namespace == "test-namespace"
 		})).Return(&resourcepb.BulkResponse{}, nil).Once() // Count phase
-		mockLegacyMigrator.On("Migrate", mock.Anything, mock.MatchedBy(func(opts legacy.MigrateOptions) bool {
+		// For test-resources GroupResource, we don't know which method it will call, but since it's not dashboards/folders/librarypanels,
+		// the Migrate will fail trying to map the resource type. Let's make it dashboards for this test.
+		mockDashboardAccess.On("MigrateDashboards", mock.Anything, mock.Anything, mock.MatchedBy(func(opts legacy.MigrateOptions) bool {
 			return !opts.OnlyCount && opts.Namespace == "test-namespace"
-		})).Return(&resourcepb.BulkResponse{}, errors.New("write error")).Once() // Write phase
+		}), mock.Anything).Return(nil, errors.New("write error")).Once() // Write phase
 
 		progress := jobs.NewMockJobProgressRecorder(t)
 		progress.On("SetMessage", mock.Anything, mock.Anything).Return()
 
 		migrator := newLegacyResourceMigrator(
 			nil,
-			mockLegacyMigrator,
+			mockDashboardAccess,
 			nil,
 			nil,
 			progress,
 			provisioning.MigrateJobOptions{},
 			"test-namespace",
-			schema.GroupResource{Group: "test.grafana.app", Resource: "test-resources"},
+			schema.GroupResource{Group: "dashboard.grafana.app", Resource: "dashboards"},
 			signature.NewGrafanaSigner(),
 		)
 
 		err := migrator.Migrate(context.Background())
 		require.Error(t, err)
-		require.Contains(t, err.Error(), "migrate legacy test-resources: write error")
+		require.Contains(t, err.Error(), "migrate legacy dashboards: write error")
 
-		mockLegacyMigrator.AssertExpectations(t)
+		mockDashboardAccess.AssertExpectations(t)
 		progress.AssertExpectations(t)
 	})
 
 	t.Run("should successfully migrate resource", func(t *testing.T) {
-		mockLegacyMigrator := legacy.NewMockLegacyMigrator(t)
-		mockLegacyMigrator.On("Migrate", mock.Anything, mock.MatchedBy(func(opts legacy.MigrateOptions) bool {
+		mockDashboardAccess := legacy.NewMockMigrationDashboardAccessor(t)
+		mockDashboardAccess.On("CountResources", mock.Anything, mock.MatchedBy(func(opts legacy.MigrateOptions) bool {
 			return opts.OnlyCount && opts.Namespace == "test-namespace"
 		})).Return(&resourcepb.BulkResponse{}, nil).Once() // Count phase
-		mockLegacyMigrator.On("Migrate", mock.Anything, mock.MatchedBy(func(opts legacy.MigrateOptions) bool {
+		mockDashboardAccess.On("MigrateDashboards", mock.Anything, mock.Anything, mock.MatchedBy(func(opts legacy.MigrateOptions) bool {
 			return !opts.OnlyCount && opts.Namespace == "test-namespace"
-		})).Return(&resourcepb.BulkResponse{}, nil).Once() // Write phase
+		}), mock.Anything).Return(&legacy.BlobStoreInfo{}, nil).Once() // Write phase
 
 		progress := jobs.NewMockJobProgressRecorder(t)
 		progress.On("SetMessage", mock.Anything, mock.Anything).Return()
 
 		migrator := newLegacyResourceMigrator(
 			nil,
-			mockLegacyMigrator,
+			mockDashboardAccess,
 			nil,
 			nil,
 			progress,
 			provisioning.MigrateJobOptions{},
 			"test-namespace",
-			schema.GroupResource{Group: "test.grafana.app", Resource: "tests"},
+			schema.GroupResource{Group: "dashboard.grafana.app", Resource: "dashboards"},
 			signature.NewGrafanaSigner(),
 		)
 
 		err := migrator.Migrate(context.Background())
 		require.NoError(t, err)
 
-		mockLegacyMigrator.AssertExpectations(t)
+		mockDashboardAccess.AssertExpectations(t)
 		progress.AssertExpectations(t)
 	})
 	t.Run("should set total to history if history is greater than count", func(t *testing.T) {
-		mockLegacyMigrator := legacy.NewMockLegacyMigrator(t)
-		mockLegacyMigrator.On("Migrate", mock.Anything, mock.MatchedBy(func(opts legacy.MigrateOptions) bool {
+		mockDashboardAccess := legacy.NewMockMigrationDashboardAccessor(t)
+		mockDashboardAccess.On("CountResources", mock.Anything, mock.MatchedBy(func(opts legacy.MigrateOptions) bool {
 			return opts.OnlyCount && opts.Namespace == "test-namespace"
 		})).Return(&resourcepb.BulkResponse{
 			Summary: []*resourcepb.BulkResponse_Summary{
 				{
-					Group:    "test.grafana.app",
-					Resource: "tests",
+					Group:    "dashboard.grafana.app",
+					Resource: "dashboards",
 					Count:    1,
 					History:  100,
 				},
 			},
 		}, nil).Once() // Count phase
-		mockLegacyMigrator.On("Migrate", mock.Anything, mock.MatchedBy(func(opts legacy.MigrateOptions) bool {
+		mockDashboardAccess.On("MigrateDashboards", mock.Anything, mock.Anything, mock.MatchedBy(func(opts legacy.MigrateOptions) bool {
 			return !opts.OnlyCount && opts.Namespace == "test-namespace"
-		})).Return(&resourcepb.BulkResponse{}, nil).Once() // Write phase
+		}), mock.Anything).Return(&legacy.BlobStoreInfo{}, nil).Once() // Write phase
 
 		progress := jobs.NewMockJobProgressRecorder(t)
 		progress.On("SetMessage", mock.Anything, mock.Anything).Return()
@@ -856,39 +854,39 @@ func TestLegacyResourceResourceMigrator_Migrate(t *testing.T) {
 
 		migrator := newLegacyResourceMigrator(
 			nil,
-			mockLegacyMigrator,
+			mockDashboardAccess,
 			nil,
 			nil,
 			progress,
 			provisioning.MigrateJobOptions{},
 			"test-namespace",
-			schema.GroupResource{Group: "test.grafana.app", Resource: "tests"},
+			schema.GroupResource{Group: "dashboard.grafana.app", Resource: "dashboards"},
 			signature.NewGrafanaSigner(),
 		)
 
 		err := migrator.Migrate(context.Background())
 		require.NoError(t, err)
 
-		mockLegacyMigrator.AssertExpectations(t)
+		mockDashboardAccess.AssertExpectations(t)
 		progress.AssertExpectations(t)
 	})
 	t.Run("should set total to count if history is less than count", func(t *testing.T) {
-		mockLegacyMigrator := legacy.NewMockLegacyMigrator(t)
-		mockLegacyMigrator.On("Migrate", mock.Anything, mock.MatchedBy(func(opts legacy.MigrateOptions) bool {
+		mockDashboardAccess := legacy.NewMockMigrationDashboardAccessor(t)
+		mockDashboardAccess.On("CountResources", mock.Anything, mock.MatchedBy(func(opts legacy.MigrateOptions) bool {
 			return opts.OnlyCount && opts.Namespace == "test-namespace"
 		})).Return(&resourcepb.BulkResponse{
 			Summary: []*resourcepb.BulkResponse_Summary{
 				{
-					Group:    "test.grafana.app",
-					Resource: "tests",
+					Group:    "dashboard.grafana.app",
+					Resource: "dashboards",
 					Count:    200,
 					History:  1,
 				},
 			},
 		}, nil).Once() // Count phase
-		mockLegacyMigrator.On("Migrate", mock.Anything, mock.MatchedBy(func(opts legacy.MigrateOptions) bool {
+		mockDashboardAccess.On("MigrateDashboards", mock.Anything, mock.Anything, mock.MatchedBy(func(opts legacy.MigrateOptions) bool {
 			return !opts.OnlyCount && opts.Namespace == "test-namespace"
-		})).Return(&resourcepb.BulkResponse{}, nil).Once() // Write phase
+		}), mock.Anything).Return(&legacy.BlobStoreInfo{}, nil).Once() // Write phase
 
 		progress := jobs.NewMockJobProgressRecorder(t)
 		progress.On("SetMessage", mock.Anything, mock.Anything).Return()
@@ -897,20 +895,20 @@ func TestLegacyResourceResourceMigrator_Migrate(t *testing.T) {
 
 		migrator := newLegacyResourceMigrator(
 			nil,
-			mockLegacyMigrator,
+			mockDashboardAccess,
 			nil,
 			nil,
 			progress,
 			provisioning.MigrateJobOptions{},
 			"test-namespace",
-			schema.GroupResource{Group: "test.grafana.app", Resource: "tests"},
+			schema.GroupResource{Group: "dashboard.grafana.app", Resource: "dashboards"},
 			signer,
 		)
 
 		err := migrator.Migrate(context.Background())
 		require.NoError(t, err)
 
-		mockLegacyMigrator.AssertExpectations(t)
+		mockDashboardAccess.AssertExpectations(t)
 		progress.AssertExpectations(t)
 	})
 }

pkg/registry/apis/provisioning/register.go

@@ -60,6 +60,7 @@ import (
 	"github.com/grafana/grafana/pkg/services/featuremgmt"
 	"github.com/grafana/grafana/pkg/setting"
 	"github.com/grafana/grafana/pkg/storage/legacysql/dualwrite"
+	"github.com/grafana/grafana/pkg/storage/unified/migrations"
 	"github.com/grafana/grafana/pkg/storage/unified/resource"
 )
 
@@ -109,7 +110,7 @@ type APIBuilder struct {
 	jobHistoryConfig *JobHistoryConfig
 	jobHistoryLoki   *jobs.LokiJobHistory
 	resourceLister   resources.ResourceLister
-	legacyMigrator   legacy.LegacyMigrator
+	dashboardAccess  legacy.MigrationDashboardAccessor
 	storageStatus    dualwrite.Service
 	unified          resource.ResourceClient
 	repoFactory      repository.Factory
@@ -135,7 +136,7 @@ func NewAPIBuilder(
 	features featuremgmt.FeatureToggles,
 	unified resource.ResourceClient,
 	configProvider apiserver.RestConfigProvider,
-	legacyMigrator legacy.LegacyMigrator,
+	dashboardAccess legacy.MigrationDashboardAccessor,
 	storageStatus dualwrite.Service,
 	usageStats usagestats.Service,
 	access authlib.AccessChecker,
@@ -158,6 +159,7 @@ func NewAPIBuilder(
 		clients = resources.NewClientFactory(configProvider)
 	}
 	parsers := resources.NewParserFactory(clients)
+	legacyMigrator := migrations.ProvideUnifiedMigrator(dashboardAccess, unified)
 	resourceLister := resources.NewResourceListerForMigrations(unified, legacyMigrator, storageStatus)
 
 	b := &APIBuilder{
@@ -170,7 +172,7 @@ func NewAPIBuilder(
 		parsers:                             parsers,
 		repositoryResources:                 resources.NewRepositoryResourcesFactory(parsers, clients, resourceLister),
 		resourceLister:                      resourceLister,
-		legacyMigrator:                      legacyMigrator,
+		dashboardAccess:                     dashboardAccess,
 		storageStatus:                       storageStatus,
 		unified:                             unified,
 		access:                              access,
@@ -234,7 +236,7 @@ func RegisterAPIService(
 	client resource.ResourceClient, // implements resource.RepositoryClient
 	configProvider apiserver.RestConfigProvider,
 	access authlib.AccessClient,
-	legacyMigrator legacy.LegacyMigrator,
+	dashboardAccess legacy.MigrationDashboardAccessor,
 	storageStatus dualwrite.Service,
 	usageStats usagestats.Service,
 	tracer tracing.Tracer,
@@ -258,7 +260,7 @@ func RegisterAPIService(
 		features,
 		client,
 		configProvider,
-		legacyMigrator, storageStatus,
+		dashboardAccess, storageStatus,
 		usageStats,
 		access,
 		tracer,
@@ -722,7 +724,7 @@ func (b *APIBuilder) GetPostStartHooks() (map[string]genericapiserver.PostStartH
 			legacyResources := migrate.NewLegacyResourcesMigrator(
 				b.repositoryResources,
 				b.parsers,
-				b.legacyMigrator,
+				b.dashboardAccess,
 				signerFactory,
 				b.clients,
 				export.ExportAll,
@@ -1241,8 +1243,9 @@ func (b *APIBuilder) tryRunningOnlyUnifiedStorage() error {
 		return nil
 	}
 
-	// Count how many things exist
-	rsp, err := b.legacyMigrator.Migrate(ctx, legacy.MigrateOptions{
+	// Count how many things exist - create a migrator on-demand for this
+	legacyMigrator := migrations.ProvideUnifiedMigrator(b.dashboardAccess, b.unified)
+	rsp, err := legacyMigrator.Migrate(ctx, legacy.MigrateOptions{
 		Namespace: "default", // FIXME! this works for single org, but need to check multi-org
 		Resources: []schema.GroupResource{{
 			Group: dashboard.GROUP, Resource: dashboard.DASHBOARD_RESOURCE,

pkg/registry/apis/provisioning/resources/object.go

@@ -12,6 +12,7 @@ import (
 	"github.com/grafana/grafana/pkg/apimachinery/utils"
 	"github.com/grafana/grafana/pkg/registry/apis/dashboard/legacy"
 	"github.com/grafana/grafana/pkg/storage/legacysql/dualwrite"
+	"github.com/grafana/grafana/pkg/storage/unified/migrations"
 	"github.com/grafana/grafana/pkg/storage/unified/resource"
 	"github.com/grafana/grafana/pkg/storage/unified/resourcepb"
 )
@@ -30,9 +31,9 @@ type ResourceStore interface {
 }
 
 type ResourceListerFromSearch struct {
-	store          ResourceStore
-	legacyMigrator legacy.LegacyMigrator
-	storageStatus  dualwrite.Service
+	store         ResourceStore
+	migrator      migrations.UnifiedMigrator
+	storageStatus dualwrite.Service
 }
 
 func NewResourceLister(store ResourceStore) ResourceLister {
@@ -42,13 +43,13 @@ func NewResourceLister(store ResourceStore) ResourceLister {
 // FIXME: the logic about migration and storage should probably be separated from this
 func NewResourceListerForMigrations(
 	store ResourceStore,
-	legacyMigrator legacy.LegacyMigrator,
+	migrator migrations.UnifiedMigrator,
 	storageStatus dualwrite.Service,
 ) ResourceLister {
 	return &ResourceListerFromSearch{
-		store:          store,
-		legacyMigrator: legacyMigrator,
-		storageStatus:  storageStatus,
+		store:         store,
+		migrator:      migrator,
+		storageStatus: storageStatus,
 	}
 }
 
@@ -133,8 +134,8 @@ func (o *ResourceListerFromSearch) Stats(ctx context.Context, namespace, reposit
 	}
 
 	// Get the stats based on what a migration could support
-	if o.storageStatus != nil && o.legacyMigrator != nil && dualwrite.IsReadingLegacyDashboardsAndFolders(ctx, o.storageStatus) {
-		rsp, err := o.legacyMigrator.Migrate(ctx, legacy.MigrateOptions{
+	if o.storageStatus != nil && o.migrator != nil && dualwrite.IsReadingLegacyDashboardsAndFolders(ctx, o.storageStatus) {
+		rsp, err := o.migrator.Migrate(ctx, legacy.MigrateOptions{
 			Namespace: namespace,
 			Resources: []schema.GroupResource{{
 				Group: dashboard.GROUP, Resource: dashboard.DASHBOARD_RESOURCE,