Rendering: Adds PDF support behind feature toggle (#81811)

* start pdf refactor

* Update AppChrome.tsx

* Update AppChrome.tsx

* add encoding param to rendering grpc service

* fix plugin mode

* clean up

* fix backend tests

* fix lint errors

* Support pdf encoding in render http api

---------

Co-authored-by: Torkel Ödegaard <torkel@grafana.com>

pkg/services/rendering/plugin_mode.go

@@ -6,14 +6,23 @@ import (
 	"fmt"
 
 	"github.com/grafana/grafana/pkg/plugins/backendplugin/pluginextensionv2"
+	"github.com/grafana/grafana/pkg/services/featuremgmt"
 )
 
-func (rs *RenderingService) renderViaPlugin(ctx context.Context, renderKey string, opts Opts) (*RenderResult, error) {
+func (rs *RenderingService) renderViaPlugin(ctx context.Context, renderType RenderType, renderKey string, opts Opts) (*RenderResult, error) {
+	if renderType == RenderPDF {
+		if !rs.features.IsEnabled(ctx, featuremgmt.FlagNewPDFRendering) {
+			return nil, fmt.Errorf("feature 'newPDFRendering' disabled")
+		}
+
+		opts.Encoding = "pdf"
+	}
+
 	// gives plugin some additional time to timeout and return possible errors.
 	ctx, cancel := context.WithTimeout(ctx, getRequestTimeout(opts.TimeoutOpts))
 	defer cancel()
 
-	filePath, err := rs.getNewFilePath(RenderPNG)
+	filePath, err := rs.getNewFilePath(renderType)
 	if err != nil {
 		return nil, err
 	}
@@ -38,6 +47,7 @@ func (rs *RenderingService) renderViaPlugin(ctx context.Context, renderKey strin
 		Domain:            rs.domain,
 		Headers:           headers,
 		AuthToken:         rs.Cfg.RendererAuthToken,
+		Encoding:          opts.Encoding,
 	}
 	rs.log.Debug("Calling renderer plugin", "req", req)