Plugins: Add file store abstraction for handling plugin files (#65432)

* add file store

* fix markdown fetch bug

* add markdown tests

* fix var name

pkg/plugins/manager/dashboards/filestore.go

@@ -3,7 +3,6 @@ package dashboards
 import (
 	"context"
 	"fmt"
-	"io/fs"
 	"strings"
 
 	"github.com/grafana/grafana/pkg/plugins"
@@ -13,17 +12,24 @@ import (
 var _ FileStore = (*FileStoreManager)(nil)
 
 type FileStoreManager struct {
-	pluginStore plugins.Store
+	pluginStore     plugins.Store
+	pluginFileStore plugins.FileStore
 }
 
-func ProvideFileStoreManager(pluginStore plugins.Store) *FileStoreManager {
+func ProvideFileStoreManager(pluginStore plugins.Store, pluginFileStore plugins.FileStore) *FileStoreManager {
 	return &FileStoreManager{
-		pluginStore: pluginStore,
+		pluginStore:     pluginStore,
+		pluginFileStore: pluginFileStore,
 	}
 }
 
-var openDashboardFile = func(p plugins.PluginDTO, name string) (fs.File, error) {
-	return p.File(name)
+var openDashboardFile = func(ctx context.Context, pluginFileStore plugins.FileStore, pluginID, name string) (*plugins.File, error) {
+	f, err := pluginFileStore.File(ctx, pluginID, name)
+	if err != nil {
+		return &plugins.File{}, err
+	}
+
+	return f, nil
 }
 
 func (m *FileStoreManager) ListPluginDashboardFiles(ctx context.Context, args *ListPluginDashboardFilesArgs) (*ListPluginDashboardFilesResult, error) {
@@ -86,12 +92,12 @@ func (m *FileStoreManager) GetPluginDashboardFileContents(ctx context.Context, a
 		return nil, err
 	}
 
-	file, err := openDashboardFile(plugin, cleanPath)
+	file, err := openDashboardFile(ctx, m.pluginFileStore, plugin.ID, cleanPath)
 	if err != nil {
 		return nil, err
 	}
 
 	return &GetPluginDashboardFileContentsResult{
-		Content: file,
+		Content: file.Content,
 	}, nil
 }

pkg/plugins/manager/dashboards/filestore_test.go

@@ -3,7 +3,6 @@ package dashboards
 import (
 	"context"
 	"io"
-	"io/fs"
 	"testing"
 	"testing/fstest"
 
@@ -131,10 +130,13 @@ func TestDashboardFileStore(t *testing.T) {
 					Data: []byte("dash2"),
 				},
 			}
-			openDashboardFile = func(p plugins.PluginDTO, name string) (fs.File, error) {
+			openDashboardFile = func(ctx context.Context, pluginFiles plugins.FileStore, pluginID, name string) (*plugins.File, error) {
 				f, err := mapFs.Open(name)
 				require.NoError(t, err)
-				return f, nil
+
+				b, err := io.ReadAll(f)
+				require.NoError(t, err)
+				return &plugins.File{Content: b}, nil
 			}
 			t.Cleanup(func() {
 				openDashboardFile = origOpenDashboardFile
@@ -157,10 +159,7 @@ func TestDashboardFileStore(t *testing.T) {
 				})
 				require.NoError(t, err)
 				require.NotNil(t, res)
-				require.NotNil(t, res.Content)
-				b, err := io.ReadAll(res.Content)
-				require.NoError(t, err)
-				require.Equal(t, "dash1", string(b))
+				require.Equal(t, "dash1", string(res.Content))
 			})
 
 			t.Run("Should return file content for dashboards/dash2.json", func(t *testing.T) {
@@ -170,10 +169,7 @@ func TestDashboardFileStore(t *testing.T) {
 				})
 				require.NoError(t, err)
 				require.NotNil(t, res)
-				require.NotNil(t, res.Content)
-				b, err := io.ReadAll(res.Content)
-				require.NoError(t, err)
-				require.Equal(t, "dash2", string(b))
+				require.Equal(t, "dash2", string(res.Content))
 			})
 
 			t.Run("Should return error when trying to read relative file", func(t *testing.T) {

pkg/plugins/manager/dashboards/ifaces.go

@@ -2,7 +2,6 @@ package dashboards
 
 import (
 	"context"
-	"io"
 )
 
 // FileStore is the interface for plugin dashboard file storage.
@@ -31,5 +30,5 @@ type GetPluginDashboardFileContentsArgs struct {
 
 // GetPluginDashboardFileContentsResult get plugin dashboard file content result model.
 type GetPluginDashboardFileContentsResult struct {
-	Content io.ReadCloser
+	Content []byte
 }

pkg/plugins/manager/fakes/fakes.go

@@ -421,3 +421,14 @@ func (s *FakePluginSource) DefaultSignature(ctx context.Context) (plugins.Signat
 	}
 	return plugins.Signature{}, false
 }
+
+type FakePluginFileStore struct {
+	FileFunc func(ctx context.Context, pluginID, filename string) (*plugins.File, error)
+}
+
+func (f *FakePluginFileStore) File(ctx context.Context, pluginID, filename string) (*plugins.File, error) {
+	if f.FileFunc != nil {
+		return f.FileFunc(ctx, pluginID, filename)
+	}
+	return nil, nil
+}

pkg/plugins/manager/filestore/fs.go

@@ -0,0 +1,54 @@
+package filestore
+
+import (
+	"context"
+	"io"
+
+	"github.com/grafana/grafana/pkg/plugins"
+	"github.com/grafana/grafana/pkg/plugins/log"
+	"github.com/grafana/grafana/pkg/plugins/manager/registry"
+)
+
+type Service struct {
+	pluginRegistry registry.Service
+	log            log.Logger
+}
+
+func ProvideService(pluginRegistry registry.Service) *Service {
+	return &Service{
+		pluginRegistry: pluginRegistry,
+		log:            log.New("plugin.fs"),
+	}
+}
+
+func (s *Service) File(ctx context.Context, pluginID, filename string) (*plugins.File, error) {
+	if p, exists := s.pluginRegistry.Plugin(ctx, pluginID); exists {
+		f, err := p.File(filename)
+		if err != nil {
+			return nil, err
+		}
+		defer func() {
+			err = f.Close()
+			if err != nil {
+				s.log.Error("Could not close plugin file", "pluginID", p.ID, "file", filename)
+			}
+		}()
+
+		b, err := io.ReadAll(f)
+		if err != nil {
+			return nil, err
+		}
+
+		fi, err := f.Stat()
+		if err != nil {
+			return nil, err
+		}
+
+		return &plugins.File{
+			Content: b,
+			ModTime: fi.ModTime(),
+		}, nil
+	} else {
+		return nil, plugins.ErrPluginNotInstalled
+	}
+}