Plugins: Update client to use SDK resource contract (#42888)

* client uses sdk resource handler

* apply pr feedback

pkg/api/datasources.go

@@ -395,18 +395,7 @@ func (hs *HTTPServer) CallDatasourceResource(c *models.ReqContext) {
 		return
 	}
 
-	dsInstanceSettings, err := adapters.ModelToInstanceSettings(ds, hs.decryptSecureJsonDataFn())
+	hs.callPluginResource(c, plugin.ID, ds.Uid)
-	if err != nil {
-		c.JsonApiErr(500, "Unable to process datasource instance model", err)
-	}
-
-	pCtx := backend.PluginContext{
-		User:                       adapters.BackendUserFromSignedInUser(c.SignedInUser),
-		OrgID:                      c.OrgId,
-		PluginID:                   plugin.ID,
-		DataSourceInstanceSettings: dsInstanceSettings,
-	}
-	hs.pluginClient.CallResource(pCtx, c, web.Params(c.Req)["*"])
 }
 
 func convertModelToDtos(ds *models.DataSource) dtos.DataSource {

pkg/api/plugins.go

@@ -5,12 +5,15 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"io"
 	"io/ioutil"
 	"net/http"
+	"net/url"
 	"os"
 	"path/filepath"
 	"sort"
 	"strings"
+	"sync"
 
 	"github.com/grafana/grafana-plugin-sdk-go/backend"
 	"github.com/grafana/grafana/pkg/api/dtos"
@@ -22,6 +25,8 @@ import (
 	"github.com/grafana/grafana/pkg/plugins/backendplugin"
 	"github.com/grafana/grafana/pkg/plugins/manager/installer"
 	"github.com/grafana/grafana/pkg/setting"
+	"github.com/grafana/grafana/pkg/util/errutil"
+	"github.com/grafana/grafana/pkg/util/proxyutil"
 	"github.com/grafana/grafana/pkg/web"
 )
 
@@ -390,18 +395,7 @@ func (hs *HTTPServer) CheckHealth(c *models.ReqContext) response.Response {
 //
 // /api/plugins/:pluginId/resources/*
 func (hs *HTTPServer) CallResource(c *models.ReqContext) {
-	pluginID := web.Params(c.Req)[":pluginId"]
+	hs.callPluginResource(c, web.Params(c.Req)[":pluginId"], "")
-
-	pCtx, found, err := hs.PluginContextProvider.Get(c.Req.Context(), pluginID, "", c.SignedInUser, false)
-	if err != nil {
-		c.JsonApiErr(500, "Failed to get plugin settings", err)
-		return
-	}
-	if !found {
-		c.JsonApiErr(404, "Plugin not found", nil)
-		return
-	}
-	hs.pluginClient.CallResource(pCtx, c, web.Params(c.Req)["*"])
 }
 
 func (hs *HTTPServer) GetPluginErrorsList(_ *models.ReqContext) response.Response {
@@ -522,3 +516,218 @@ func (hs *HTTPServer) pluginMarkdown(ctx context.Context, pluginId string, name
 func mdFilepath(mdFilename string) string {
 	return filepath.Clean(filepath.Join("/", fmt.Sprintf("%s.md", mdFilename)))
 }
+
+func (hs *HTTPServer) callPluginResource(c *models.ReqContext, pluginID, dsUID string) {
+	pCtx, found, err := hs.PluginContextProvider.Get(c.Req.Context(), pluginID, dsUID, c.SignedInUser, false)
+	if err != nil {
+		c.JsonApiErr(500, "Failed to get plugin settings", err)
+		return
+	}
+	if !found {
+		c.JsonApiErr(404, "Plugin not found", nil)
+		return
+	}
+
+	var dsURL string
+	if pCtx.DataSourceInstanceSettings != nil {
+		dsURL = pCtx.DataSourceInstanceSettings.URL
+	}
+
+	err = hs.PluginRequestValidator.Validate(dsURL, c.Req)
+	if err != nil {
+		c.JsonApiErr(http.StatusForbidden, "Access denied", err)
+		return
+	}
+
+	clonedReq := c.Req.Clone(c.Req.Context())
+	rawURL := web.Params(c.Req)["*"]
+	if clonedReq.URL.RawQuery != "" {
+		rawURL += "?" + clonedReq.URL.RawQuery
+	}
+	urlPath, err := url.Parse(rawURL)
+	if err != nil {
+		handleCallResourceError(err, c)
+		return
+	}
+	clonedReq.URL = urlPath
+
+	if err = hs.makePluginResourceRequest(c.Resp, clonedReq, pCtx); err != nil {
+		handleCallResourceError(err, c)
+	}
+}
+
+func (hs *HTTPServer) makePluginResourceRequest(w http.ResponseWriter, req *http.Request, pCtx backend.PluginContext) error {
+	keepCookieModel := struct {
+		KeepCookies []string `json:"keepCookies"`
+	}{}
+	if dis := pCtx.DataSourceInstanceSettings; dis != nil {
+		err := json.Unmarshal(dis.JSONData, &keepCookieModel)
+		if err != nil {
+			hs.log.Warn("failed to to unpack JSONData in datasource instance settings", "err", err)
+		}
+	}
+	proxyutil.ClearCookieHeader(req, keepCookieModel.KeepCookies)
+	proxyutil.PrepareProxyRequest(req)
+
+	body, err := ioutil.ReadAll(req.Body)
+	if err != nil {
+		return fmt.Errorf("failed to read request body: %w", err)
+	}
+
+	crReq := &backend.CallResourceRequest{
+		PluginContext: pCtx,
+		Path:          req.URL.Path,
+		Method:        req.Method,
+		URL:           req.URL.String(),
+		Headers:       req.Header,
+		Body:          body,
+	}
+
+	childCtx, cancel := context.WithCancel(req.Context())
+	defer cancel()
+	stream := newCallResourceResponseStream(childCtx)
+
+	var wg sync.WaitGroup
+	wg.Add(1)
+
+	defer func() {
+		if err := stream.Close(); err != nil {
+			hs.log.Warn("Failed to close plugin resource stream", "err", err)
+		}
+		wg.Wait()
+	}()
+
+	var flushStreamErr error
+	go func() {
+		flushStreamErr = hs.flushStream(stream, w)
+		wg.Done()
+	}()
+
+	if err := hs.pluginClient.CallResource(req.Context(), crReq, stream); err != nil {
+		return err
+	}
+
+	return flushStreamErr
+}
+
+func (hs *HTTPServer) flushStream(stream callResourceClientResponseStream, w http.ResponseWriter) error {
+	processedStreams := 0
+
+	for {
+		resp, err := stream.Recv()
+		if errors.Is(err, io.EOF) {
+			if processedStreams == 0 {
+				return errors.New("received empty resource response")
+			}
+			return nil
+		}
+		if err != nil {
+			if processedStreams == 0 {
+				return errutil.Wrap("failed to receive response from resource call", err)
+			}
+
+			hs.log.Error("Failed to receive response from resource call", "err", err)
+			return stream.Close()
+		}
+
+		// Expected that headers and status are only part of first stream
+		if processedStreams == 0 && resp.Headers != nil {
+			// Make sure a content type always is returned in response
+			if _, exists := resp.Headers["Content-Type"]; !exists {
+				resp.Headers["Content-Type"] = []string{"application/json"}
+			}
+
+			for k, values := range resp.Headers {
+				// Due to security reasons we don't want to forward
+				// cookies from a backend plugin to clients/browsers.
+				if k == "Set-Cookie" {
+					continue
+				}
+
+				for _, v := range values {
+					// TODO: Figure out if we should use Set here instead
+					// nolint:gocritic
+					w.Header().Add(k, v)
+				}
+			}
+			w.WriteHeader(resp.Status)
+		}
+
+		if _, err := w.Write(resp.Body); err != nil {
+			hs.log.Error("Failed to write resource response", "err", err)
+		}
+
+		if flusher, ok := w.(http.Flusher); ok {
+			flusher.Flush()
+		}
+		processedStreams++
+	}
+}
+
+func handleCallResourceError(err error, reqCtx *models.ReqContext) {
+	if errors.Is(err, backendplugin.ErrPluginUnavailable) {
+		reqCtx.JsonApiErr(503, "Plugin unavailable", err)
+		return
+	}
+
+	if errors.Is(err, backendplugin.ErrMethodNotImplemented) {
+		reqCtx.JsonApiErr(404, "Not found", err)
+		return
+	}
+
+	reqCtx.JsonApiErr(500, "Failed to call resource", err)
+}
+
+// callResourceClientResponseStream is used for receiving resource call responses.
+type callResourceClientResponseStream interface {
+	Recv() (*backend.CallResourceResponse, error)
+	Close() error
+}
+
+type callResourceResponseStream struct {
+	ctx    context.Context
+	stream chan *backend.CallResourceResponse
+	closed bool
+}
+
+func newCallResourceResponseStream(ctx context.Context) *callResourceResponseStream {
+	return &callResourceResponseStream{
+		ctx:    ctx,
+		stream: make(chan *backend.CallResourceResponse),
+	}
+}
+
+func (s *callResourceResponseStream) Send(res *backend.CallResourceResponse) error {
+	if s.closed {
+		return errors.New("cannot send to a closed stream")
+	}
+
+	select {
+	case <-s.ctx.Done():
+		return errors.New("cancelled")
+	case s.stream <- res:
+		return nil
+	}
+}
+
+func (s *callResourceResponseStream) Recv() (*backend.CallResourceResponse, error) {
+	select {
+	case <-s.ctx.Done():
+		return nil, s.ctx.Err()
+	case res, ok := <-s.stream:
+		if !ok {
+			return nil, io.EOF
+		}
+		return res, nil
+	}
+}
+
+func (s *callResourceResponseStream) Close() error {
+	if s.closed {
+		return errors.New("cannot close a closed stream")
+	}
+
+	close(s.stream)
+	s.closed = true
+	return nil
+}

pkg/plugins/ifaces.go

@@ -55,9 +55,8 @@ type Client interface {
 	backend.QueryDataHandler
 	backend.CheckHealthHandler
 	backend.StreamHandler
+	backend.CallResourceHandler
 
-	// CallResource calls a plugin resource.
-	CallResource(pCtx backend.PluginContext, ctx *models.ReqContext, path string)
 	// CollectMetrics collects metrics from a plugin.
 	CollectMetrics(ctx context.Context, pluginID string) (*backend.CollectMetricsResult, error)
 }

pkg/plugins/manager/manager.go

@@ -2,13 +2,9 @@ package manager
 
 import (
 	"context"
-	"encoding/json"
 	"errors"
 	"fmt"
-	"io"
-	"io/ioutil"
 	"net/http"
-	"net/url"
 	"os"
 	"path/filepath"
 	"sync"
@@ -26,7 +22,6 @@ import (
 	"github.com/grafana/grafana/pkg/services/sqlstore"
 	"github.com/grafana/grafana/pkg/setting"
 	"github.com/grafana/grafana/pkg/util/errutil"
-	"github.com/grafana/grafana/pkg/util/proxyutil"
 )
 
 const (
@@ -249,161 +244,24 @@ func (m *PluginManager) QueryData(ctx context.Context, req *backend.QueryDataReq
 	return resp, err
 }
 
-func (m *PluginManager) CallResource(pCtx backend.PluginContext, reqCtx *models.ReqContext, path string) {
+func (m *PluginManager) CallResource(ctx context.Context, req *backend.CallResourceRequest, sender backend.CallResourceResponseSender) error {
-	var dsURL string
+	p, exists := m.plugin(req.PluginContext.PluginID)
-	if pCtx.DataSourceInstanceSettings != nil {
-		dsURL = pCtx.DataSourceInstanceSettings.URL
-	}
-
-	err := m.requestValidator.Validate(dsURL, reqCtx.Req)
-	if err != nil {
-		reqCtx.JsonApiErr(http.StatusForbidden, "Access denied", err)
-		return
-	}
-
-	clonedReq := reqCtx.Req.Clone(reqCtx.Req.Context())
-	rawURL := path
-	if clonedReq.URL.RawQuery != "" {
-		rawURL += "?" + clonedReq.URL.RawQuery
-	}
-	urlPath, err := url.Parse(rawURL)
-	if err != nil {
-		handleCallResourceError(err, reqCtx)
-		return
-	}
-	clonedReq.URL = urlPath
-	err = m.callResourceInternal(reqCtx.Resp, clonedReq, pCtx)
-	if err != nil {
-		handleCallResourceError(err, reqCtx)
-	}
-}
-
-func (m *PluginManager) callResourceInternal(w http.ResponseWriter, req *http.Request, pCtx backend.PluginContext) error {
-	p, exists := m.plugin(pCtx.PluginID)
 	if !exists {
 		return backendplugin.ErrPluginNotRegistered
 	}
 
-	keepCookieModel := keepCookiesJSONModel{}
+	err := instrumentation.InstrumentCallResourceRequest(p.PluginID(), func() error {
-	if dis := pCtx.DataSourceInstanceSettings; dis != nil {
+		if err := p.CallResource(ctx, req, sender); err != nil {
-		err := json.Unmarshal(dis.JSONData, &keepCookieModel)
-		if err != nil {
-			p.Logger().Error("Failed to to unpack JSONData in datasource instance settings", "err", err)
-		}
-	}
-
-	proxyutil.ClearCookieHeader(req, keepCookieModel.KeepCookies)
-	proxyutil.PrepareProxyRequest(req)
-
-	body, err := ioutil.ReadAll(req.Body)
-	if err != nil {
-		return fmt.Errorf("failed to read request body: %w", err)
-	}
-
-	crReq := &backend.CallResourceRequest{
-		PluginContext: pCtx,
-		Path:          req.URL.Path,
-		Method:        req.Method,
-		URL:           req.URL.String(),
-		Headers:       req.Header,
-		Body:          body,
-	}
-
-	return instrumentation.InstrumentCallResourceRequest(p.PluginID(), func() error {
-		childCtx, cancel := context.WithCancel(req.Context())
-		defer cancel()
-		stream := newCallResourceResponseStream(childCtx)
-
-		var wg sync.WaitGroup
-		wg.Add(1)
-
-		defer func() {
-			if err := stream.Close(); err != nil {
-				m.log.Warn("Failed to close stream", "err", err)
-			}
-			wg.Wait()
-		}()
-
-		var flushStreamErr error
-		go func() {
-			flushStreamErr = flushStream(p, stream, w)
-			wg.Done()
-		}()
-
-		if err := p.CallResource(req.Context(), crReq, stream); err != nil {
 			return err
 		}
-
+		return nil
-		return flushStreamErr
 	})
-}
 
-func handleCallResourceError(err error, reqCtx *models.ReqContext) {
+	if err != nil {
-	if errors.Is(err, backendplugin.ErrPluginUnavailable) {
+		return err
-		reqCtx.JsonApiErr(503, "Plugin unavailable", err)
-		return
 	}
 
-	if errors.Is(err, backendplugin.ErrMethodNotImplemented) {
+	return nil
-		reqCtx.JsonApiErr(404, "Not found", err)
-		return
-	}
-
-	reqCtx.JsonApiErr(500, "Failed to call resource", err)
-}
-
-func flushStream(plugin backendplugin.Plugin, stream callResourceClientResponseStream, w http.ResponseWriter) error {
-	processedStreams := 0
-
-	for {
-		resp, err := stream.Recv()
-		if errors.Is(err, io.EOF) {
-			if processedStreams == 0 {
-				return errors.New("received empty resource response")
-			}
-			return nil
-		}
-		if err != nil {
-			if processedStreams == 0 {
-				return errutil.Wrap("failed to receive response from resource call", err)
-			}
-
-			plugin.Logger().Error("Failed to receive response from resource call", "err", err)
-			return stream.Close()
-		}
-
-		// Expected that headers and status are only part of first stream
-		if processedStreams == 0 && resp.Headers != nil {
-			// Make sure a content type always is returned in response
-			if _, exists := resp.Headers["Content-Type"]; !exists {
-				resp.Headers["Content-Type"] = []string{"application/json"}
-			}
-
-			for k, values := range resp.Headers {
-				// Due to security reasons we don't want to forward
-				// cookies from a backend plugin to clients/browsers.
-				if k == "Set-Cookie" {
-					continue
-				}
-
-				for _, v := range values {
-					// TODO: Figure out if we should use Set here instead
-					// nolint:gocritic
-					w.Header().Add(k, v)
-				}
-			}
-			w.WriteHeader(resp.Status)
-		}
-
-		if _, err := w.Write(resp.Body); err != nil {
-			plugin.Logger().Error("Failed to write resource response", "err", err)
-		}
-
-		if flusher, ok := w.(http.Flusher); ok {
-			flusher.Flush()
-		}
-		processedStreams++
-	}
 }
 
 func (m *PluginManager) CollectMetrics(ctx context.Context, pluginID string) (*backend.CollectMetricsResult, error) {
@@ -694,61 +552,3 @@ func (m *PluginManager) pluginSettingPaths() []string {
 
 	return pluginSettingDirs
 }
-
-// callResourceClientResponseStream is used for receiving resource call responses.
-type callResourceClientResponseStream interface {
-	Recv() (*backend.CallResourceResponse, error)
-	Close() error
-}
-
-type keepCookiesJSONModel struct {
-	KeepCookies []string `json:"keepCookies"`
-}
-
-type callResourceResponseStream struct {
-	ctx    context.Context
-	stream chan *backend.CallResourceResponse
-	closed bool
-}
-
-func newCallResourceResponseStream(ctx context.Context) *callResourceResponseStream {
-	return &callResourceResponseStream{
-		ctx:    ctx,
-		stream: make(chan *backend.CallResourceResponse),
-	}
-}
-
-func (s *callResourceResponseStream) Send(res *backend.CallResourceResponse) error {
-	if s.closed {
-		return errors.New("cannot send to a closed stream")
-	}
-
-	select {
-	case <-s.ctx.Done():
-		return errors.New("cancelled")
-	case s.stream <- res:
-		return nil
-	}
-}
-
-func (s *callResourceResponseStream) Recv() (*backend.CallResourceResponse, error) {
-	select {
-	case <-s.ctx.Done():
-		return nil, s.ctx.Err()
-	case res, ok := <-s.stream:
-		if !ok {
-			return nil, io.EOF
-		}
-		return res, nil
-	}
-}
-
-func (s *callResourceResponseStream) Close() error {
-	if s.closed {
-		return errors.New("cannot close a closed stream")
-	}
-
-	close(s.stream)
-	s.closed = true
-	return nil
-}

pkg/plugins/manager/manager_test.go

@@ -1,10 +1,8 @@
 package manager
 
 import (
-	"bytes"
 	"context"
 	"net/http"
-	"net/http/httptest"
 	"os"
 	"path/filepath"
 	"sync"
@@ -399,14 +397,6 @@ func TestPluginManager_lifecycle_managed(t *testing.T) {
 						_, err = ctx.manager.CheckHealth(context.Background(), &backend.CheckHealthRequest{PluginContext: backend.PluginContext{PluginID: testPluginID}})
 						require.Equal(t, backendplugin.ErrMethodNotImplemented, err)
 					})
-
-					t.Run("Call resource should return method not implemented error", func(t *testing.T) {
-						req, err := http.NewRequest(http.MethodGet, "/test", bytes.NewReader([]byte{}))
-						require.NoError(t, err)
-						w := httptest.NewRecorder()
-						err = ctx.manager.callResourceInternal(w, req, backend.PluginContext{PluginID: testPluginID})
-						require.Equal(t, backendplugin.ErrMethodNotImplemented, err)
-					})
 				})
 
 				t.Run("Implemented handlers", func(t *testing.T) {
@@ -451,12 +441,11 @@ func TestPluginManager_lifecycle_managed(t *testing.T) {
 							})
 						}
 
-						req, err := http.NewRequest(http.MethodGet, "/test", bytes.NewReader([]byte{}))
+						sender := &fakeSender{}
+						err = ctx.manager.CallResource(context.Background(), &backend.CallResourceRequest{PluginContext: backend.PluginContext{PluginID: testPluginID}}, sender)
 						require.NoError(t, err)
-						w := httptest.NewRecorder()
+						require.NotNil(t, sender.resp)
-						err = ctx.manager.callResourceInternal(w, req, backend.PluginContext{PluginID: testPluginID})
+						require.Equal(t, http.StatusOK, sender.resp.Status)
-						require.NoError(t, err)
-						require.Equal(t, http.StatusOK, w.Code)
 					})
 				})
 			})
@@ -604,17 +593,17 @@ type fakePluginInstaller struct {
 	uninstallCount int
 }
 
-func (f *fakePluginInstaller) Install(ctx context.Context, pluginID, version, pluginsDir, pluginZipURL, pluginRepoURL string) error {
+func (f *fakePluginInstaller) Install(_ context.Context, _, _, _, _, _ string) error {
 	f.installCount++
 	return nil
 }
 
-func (f *fakePluginInstaller) Uninstall(ctx context.Context, pluginPath string) error {
+func (f *fakePluginInstaller) Uninstall(_ context.Context, _ string) error {
 	f.uninstallCount++
 	return nil
 }
 
-func (f *fakePluginInstaller) GetUpdateInfo(ctx context.Context, pluginID, version, pluginRepoURL string) (plugins.UpdateInfo, error) {
+func (f *fakePluginInstaller) GetUpdateInfo(_ context.Context, _, _, _ string) (plugins.UpdateInfo, error) {
 	return plugins.UpdateInfo{}, nil
 }
 
@@ -627,13 +616,13 @@ type fakeLoader struct {
 	plugins.Loader
 }
 
-func (l *fakeLoader) Load(paths []string, ignore map[string]struct{}) ([]*plugins.Plugin, error) {
+func (l *fakeLoader) Load(paths []string, _ map[string]struct{}) ([]*plugins.Plugin, error) {
 	l.loadedPaths = append(l.loadedPaths, paths...)
 
 	return l.mockedLoadedPlugins, nil
 }
 
-func (l *fakeLoader) LoadWithFactory(path string, factory backendplugin.PluginFactoryFunc) (*plugins.Plugin, error) {
+func (l *fakeLoader) LoadWithFactory(path string, _ backendplugin.PluginFactoryFunc) (*plugins.Plugin, error) {
 	l.loadedPaths = append(l.loadedPaths, path)
 
 	return l.mockedFactoryLoadedPlugin, nil
@@ -656,102 +645,102 @@ type fakePluginClient struct {
 	backendplugin.Plugin
 }
 
-func (tp *fakePluginClient) PluginID() string {
+func (pc *fakePluginClient) PluginID() string {
-	return tp.pluginID
+	return pc.pluginID
 }
 
-func (tp *fakePluginClient) Logger() log.Logger {
+func (pc *fakePluginClient) Logger() log.Logger {
-	return tp.logger
+	return pc.logger
 }
 
-func (tp *fakePluginClient) Start(ctx context.Context) error {
+func (pc *fakePluginClient) Start(_ context.Context) error {
-	tp.mutex.Lock()
+	pc.mutex.Lock()
-	defer tp.mutex.Unlock()
+	defer pc.mutex.Unlock()
-	tp.exited = false
+	pc.exited = false
-	tp.startCount++
+	pc.startCount++
 	return nil
 }
 
-func (tp *fakePluginClient) Stop(ctx context.Context) error {
+func (pc *fakePluginClient) Stop(_ context.Context) error {
-	tp.mutex.Lock()
+	pc.mutex.Lock()
-	defer tp.mutex.Unlock()
+	defer pc.mutex.Unlock()
-	tp.stopCount++
+	pc.stopCount++
-	tp.exited = true
+	pc.exited = true
 	return nil
 }
 
-func (tp *fakePluginClient) IsManaged() bool {
+func (pc *fakePluginClient) IsManaged() bool {
-	return tp.managed
+	return pc.managed
 }
 
-func (tp *fakePluginClient) Exited() bool {
+func (pc *fakePluginClient) Exited() bool {
-	tp.mutex.RLock()
+	pc.mutex.RLock()
-	defer tp.mutex.RUnlock()
+	defer pc.mutex.RUnlock()
-	return tp.exited
+	return pc.exited
 }
 
-func (tp *fakePluginClient) Decommission() error {
+func (pc *fakePluginClient) Decommission() error {
-	tp.mutex.Lock()
+	pc.mutex.Lock()
-	defer tp.mutex.Unlock()
+	defer pc.mutex.Unlock()
 
-	tp.decommissioned = true
+	pc.decommissioned = true
 
 	return nil
 }
 
-func (tp *fakePluginClient) IsDecommissioned() bool {
+func (pc *fakePluginClient) IsDecommissioned() bool {
-	tp.mutex.RLock()
+	pc.mutex.RLock()
-	defer tp.mutex.RUnlock()
+	defer pc.mutex.RUnlock()
-	return tp.decommissioned
+	return pc.decommissioned
 }
 
-func (tp *fakePluginClient) kill() {
+func (pc *fakePluginClient) kill() {
-	tp.mutex.Lock()
+	pc.mutex.Lock()
-	defer tp.mutex.Unlock()
+	defer pc.mutex.Unlock()
-	tp.exited = true
+	pc.exited = true
 }
 
-func (tp *fakePluginClient) CollectMetrics(ctx context.Context) (*backend.CollectMetricsResult, error) {
+func (pc *fakePluginClient) CollectMetrics(ctx context.Context) (*backend.CollectMetricsResult, error) {
-	if tp.CollectMetricsHandlerFunc != nil {
+	if pc.CollectMetricsHandlerFunc != nil {
-		return tp.CollectMetricsHandlerFunc(ctx)
+		return pc.CollectMetricsHandlerFunc(ctx)
 	}
 
 	return nil, backendplugin.ErrMethodNotImplemented
 }
 
-func (tp *fakePluginClient) CheckHealth(ctx context.Context, req *backend.CheckHealthRequest) (*backend.CheckHealthResult, error) {
+func (pc *fakePluginClient) CheckHealth(ctx context.Context, req *backend.CheckHealthRequest) (*backend.CheckHealthResult, error) {
-	if tp.CheckHealthHandlerFunc != nil {
+	if pc.CheckHealthHandlerFunc != nil {
-		return tp.CheckHealthHandlerFunc(ctx, req)
+		return pc.CheckHealthHandlerFunc(ctx, req)
 	}
 
 	return nil, backendplugin.ErrMethodNotImplemented
 }
 
-func (tp *fakePluginClient) QueryData(ctx context.Context, req *backend.QueryDataRequest) (*backend.QueryDataResponse, error) {
+func (pc *fakePluginClient) QueryData(ctx context.Context, req *backend.QueryDataRequest) (*backend.QueryDataResponse, error) {
-	if tp.QueryDataHandlerFunc != nil {
+	if pc.QueryDataHandlerFunc != nil {
-		return tp.QueryDataHandlerFunc(ctx, req)
+		return pc.QueryDataHandlerFunc(ctx, req)
 	}
 
 	return nil, backendplugin.ErrMethodNotImplemented
 }
 
-func (tp *fakePluginClient) CallResource(ctx context.Context, req *backend.CallResourceRequest, sender backend.CallResourceResponseSender) error {
+func (pc *fakePluginClient) CallResource(ctx context.Context, req *backend.CallResourceRequest, sender backend.CallResourceResponseSender) error {
-	if tp.CallResourceHandlerFunc != nil {
+	if pc.CallResourceHandlerFunc != nil {
-		return tp.CallResourceHandlerFunc(ctx, req, sender)
+		return pc.CallResourceHandlerFunc(ctx, req, sender)
 	}
 
 	return backendplugin.ErrMethodNotImplemented
 }
 
-func (tp *fakePluginClient) SubscribeStream(ctx context.Context, request *backend.SubscribeStreamRequest) (*backend.SubscribeStreamResponse, error) {
+func (pc *fakePluginClient) SubscribeStream(_ context.Context, _ *backend.SubscribeStreamRequest) (*backend.SubscribeStreamResponse, error) {
 	return nil, backendplugin.ErrMethodNotImplemented
 }
 
-func (tp *fakePluginClient) PublishStream(ctx context.Context, request *backend.PublishStreamRequest) (*backend.PublishStreamResponse, error) {
+func (pc *fakePluginClient) PublishStream(_ context.Context, _ *backend.PublishStreamRequest) (*backend.PublishStreamResponse, error) {
 	return nil, backendplugin.ErrMethodNotImplemented
 }
 
-func (tp *fakePluginClient) RunStream(ctx context.Context, request *backend.RunStreamRequest, sender *backend.StreamSender) error {
+func (pc *fakePluginClient) RunStream(_ context.Context, _ *backend.RunStreamRequest, _ *backend.StreamSender) error {
 	return backendplugin.ErrMethodNotImplemented
 }
 
@@ -765,10 +754,20 @@ type fakeLogger struct {
 	log.Logger
 }
 
-func (tl fakeLogger) Info(msg string, ctx ...interface{}) {
+func (l fakeLogger) Info(_ string, _ ...interface{}) {
 
 }
 
-func (tl fakeLogger) Debug(msg string, ctx ...interface{}) {
+func (l fakeLogger) Debug(_ string, _ ...interface{}) {
 
 }
+
+type fakeSender struct {
+	resp *backend.CallResourceResponse
+}
+
+func (s *fakeSender) Send(crr *backend.CallResourceResponse) error {
+	s.resp = crr
+
+	return nil
+}