Renderer: add version information (#34964)

* Renderer: add version information

* fix alerting test

pkg/services/rendering/http_mode.go

@@ -2,6 +2,7 @@ package rendering
 
 import (
 	"context"
+	"encoding/json"
 	"errors"
 	"fmt"
 	"io"
@@ -192,3 +193,35 @@ func (rs *RenderingService) readFileResponse(ctx context.Context, resp *http.Res
 
 	return nil
 }
+
+func (rs *RenderingService) getRemotePluginVersion() (string, error) {
+	rendererURL, err := url.Parse(rs.Cfg.RendererUrl + "/version")
+	if err != nil {
+		return "", err
+	}
+
+	headers := make(map[string][]string)
+	resp, err := rs.doRequest(context.Background(), rendererURL, headers)
+	if err != nil {
+		return "", err
+	}
+
+	defer func() {
+		if err := resp.Body.Close(); err != nil {
+			rs.log.Warn("Failed to close response body", "err", err)
+		}
+	}()
+
+	if resp.StatusCode != http.StatusOK {
+		return "", fmt.Errorf("remote rendering request to get version failed, status code: %d, status: %s", resp.StatusCode,
+			resp.Status)
+	}
+
+	var info struct {
+		Version string
+	}
+	if err := json.NewDecoder(resp.Body).Decode(&info); err != nil {
+		return "", err
+	}
+	return info.Version, nil
+}

pkg/services/rendering/interface.go

@@ -60,6 +60,7 @@ type renderCSVFunc func(ctx context.Context, renderKey string, options CSVOpts)
 
 type Service interface {
 	IsAvailable() bool
+	Version() string
 	Render(ctx context.Context, opts Opts) (*RenderResult, error)
 	RenderCSV(ctx context.Context, opts CSVOpts) (*RenderCSVResult, error)
 	RenderErrorImage(error error) (*RenderResult, error)

pkg/services/rendering/rendering.go

@@ -47,6 +47,7 @@ type RenderingService struct {
 	renderCSVAction renderCSVFunc
 	domain          string
 	inProgressCount int
+	version         string
 
 	Cfg                *setting.Cfg             `inject:""`
 	RemoteCacheService *remotecache.RemoteCache `inject:""`
@@ -86,7 +87,14 @@ func (rs *RenderingService) Init() error {
 func (rs *RenderingService) Run(ctx context.Context) error {
 	if rs.remoteAvailable() {
 		rs.log = rs.log.New("renderer", "http")
-		rs.log.Info("Backend rendering via external http server")
+
+		version, err := rs.getRemotePluginVersion()
+		if err != nil {
+			rs.log.Info("Couldn't get remote renderer version", "err", err)
+		}
+
+		rs.log.Info("Backend rendering via external http server", "version", version)
+		rs.version = version
 		rs.renderAction = rs.renderViaHTTP
 		rs.renderCSVAction = rs.renderCSVViaHTTP
 		<-ctx.Done()
@@ -101,6 +109,7 @@ func (rs *RenderingService) Run(ctx context.Context) error {
 			return err
 		}
 
+		rs.version = rs.pluginInfo.Info.Version
 		rs.renderAction = rs.renderViaPlugin
 		rs.renderCSVAction = rs.renderCSVViaPlugin
 		<-ctx.Done()
@@ -127,6 +136,10 @@ func (rs *RenderingService) IsAvailable() bool {
 	return rs.remoteAvailable() || rs.pluginAvailable()
 }
 
+func (rs *RenderingService) Version() string {
+	return rs.version
+}
+
 func (rs *RenderingService) RenderErrorImage(err error) (*RenderResult, error) {
 	imgUrl := "public/img/rendering_error.png"