Backend image rendering as plugin (#11966)

* rendering: headless chrome progress

* renderer: minor change

* grpc: version hell

* updated grpc libs

* wip: minor progess

* rendering: new image rendering plugin is starting to work

* feat: now phantomjs works as well and updated alerting to use new rendering service

* refactor: renamed renderer package and service to rendering to make renderer name less confusing (rendering is internal service that handles the renderer plugin now)

* rendering: now render key is passed and render auth is working in plugin mode

* removed unneeded lines from gitignore

* rendering: now plugin mode supports waiting for all panels to complete rendering

* fix: LastSeenAt fix for render calls, was not set which causes a lot of updates to Last Seen at during rendering, this should fix sqlite db locked issues in seen in previous releases

* change: changed render tz url parameter to use proper timezone name as chrome does not handle UTC offset TZ values

* fix: another update to tz param generation

* renderer: added http mode to renderer service, new ini setting [rendering] server_url

pkg/api/api.go

@@ -375,7 +375,7 @@ func (hs *HTTPServer) registerRoutes() {
 	}, reqGrafanaAdmin)
 
 	// rendering
-	r.Get("/render/*", reqSignedIn, RenderToPng)
+	r.Get("/render/*", reqSignedIn, hs.RenderToPng)
 
 	// grafana.net proxy
 	r.Any("/api/gnet/*", reqSignedIn, ProxyGnetRequest)

pkg/api/http_server.go

@@ -27,6 +27,7 @@ import (
 	"github.com/grafana/grafana/pkg/models"
 	"github.com/grafana/grafana/pkg/plugins"
 	"github.com/grafana/grafana/pkg/registry"
+	"github.com/grafana/grafana/pkg/services/rendering"
 	"github.com/grafana/grafana/pkg/setting"
 )
 
@@ -42,8 +43,10 @@ type HTTPServer struct {
 	cache         *gocache.Cache
 	httpSrv       *http.Server
 
-	RouteRegister RouteRegister `inject:""`
-	Bus           bus.Bus       `inject:""`
+	RouteRegister RouteRegister     `inject:""`
+	Bus           bus.Bus           `inject:""`
+	RenderService rendering.Service `inject:""`
+	Cfg           *setting.Cfg      `inject:""`
 }
 
 func (hs *HTTPServer) Init() error {
@@ -179,7 +182,7 @@ func (hs *HTTPServer) newMacaron() *macaron.Macaron {
 	hs.mapStatic(m, setting.StaticRootPath, "robots.txt", "robots.txt")
 
 	if setting.ImageUploadProvider == "local" {
-		hs.mapStatic(m, setting.ImagesDir, "", "/public/img/attachments")
+		hs.mapStatic(m, hs.Cfg.ImagesDir, "", "/public/img/attachments")
 	}
 
 	m.Use(macaron.Renderer(macaron.RenderOptions{

pkg/api/render.go

@@ -3,35 +3,54 @@ package api
 import (
 	"fmt"
 	"net/http"
+	"strconv"
+	"time"
 
-	"github.com/grafana/grafana/pkg/components/renderer"
 	m "github.com/grafana/grafana/pkg/models"
+	"github.com/grafana/grafana/pkg/services/rendering"
 	"github.com/grafana/grafana/pkg/util"
 )
 
-func RenderToPng(c *m.ReqContext) {
+func (hs *HTTPServer) RenderToPng(c *m.ReqContext) {
 	queryReader, err := util.NewUrlQueryReader(c.Req.URL)
 	if err != nil {
 		c.Handle(400, "Render parameters error", err)
 		return
 	}
+
 	queryParams := fmt.Sprintf("?%s", c.Req.URL.RawQuery)
 
-	renderOpts := &renderer.RenderOpts{
-		Path:     c.Params("*") + queryParams,
-		Width:    queryReader.Get("width", "800"),
-		Height:   queryReader.Get("height", "400"),
-		Timeout:  queryReader.Get("timeout", "60"),
+	width, err := strconv.Atoi(queryReader.Get("width", "800"))
+	if err != nil {
+		c.Handle(400, "Render parameters error", fmt.Errorf("Cannot parse width as int: %s", err))
+		return
+	}
+
+	height, err := strconv.Atoi(queryReader.Get("height", "400"))
+	if err != nil {
+		c.Handle(400, "Render parameters error", fmt.Errorf("Cannot parse height as int: %s", err))
+		return
+	}
+
+	timeout, err := strconv.Atoi(queryReader.Get("timeout", "60"))
+	if err != nil {
+		c.Handle(400, "Render parameters error", fmt.Errorf("Cannot parse timeout as int: %s", err))
+		return
+	}
+
+	result, err := hs.RenderService.Render(c.Req.Context(), rendering.Opts{
+		Width:    width,
+		Height:   height,
+		Timeout:  time.Duration(timeout) * time.Second,
 		OrgId:    c.OrgId,
 		UserId:   c.UserId,
 		OrgRole:  c.OrgRole,
+		Path:     c.Params("*") + queryParams,
 		Timezone: queryReader.Get("tz", ""),
 		Encoding: queryReader.Get("encoding", ""),
-	}
+	})
 
-	pngPath, err := renderer.RenderToPng(renderOpts)
-
-	if err != nil && err == renderer.ErrTimeout {
+	if err != nil && err == rendering.ErrTimeout {
 		c.Handle(500, err.Error(), err)
 		return
 	}
@@ -42,5 +61,5 @@ func RenderToPng(c *m.ReqContext) {
 	}
 
 	c.Resp.Header().Set("Content-Type", "image/png")
-	http.ServeFile(c.Resp, c.Req.Request, pngPath)
+	http.ServeFile(c.Resp, c.Req.Request, result.FilePath)
 }