#44449: fix RenderingService.IsAvailable()

pkg/services/rendering/rendering.go

@@ -167,7 +167,7 @@ func (rs *RenderingService) remoteAvailable() bool {
 }
 
 func (rs *RenderingService) IsAvailable() bool {
-	return rs.remoteAvailable() || rs.pluginAvailable()
+	return (rs.remoteAvailable() && rs.Version() != "") || rs.pluginAvailable()
 }
 
 func (rs *RenderingService) Version() string {

pkg/services/rendering/rendering_test.go

@@ -150,9 +150,22 @@ func TestRenderingServiceGetRemotePluginVersion(t *testing.T) {
 	cfg := setting.NewCfg()
 	rs := &RenderingService{
 		Cfg:                   cfg,
+		RendererPluginManager: &dummyPluginManager{},
 		log:                   log.New("rendering-test"),
 	}
 
+	t.Run("When renderer url is set but version is missing", func(t *testing.T) {
+		rs.Cfg.RendererUrl = "http://localhost:8081/render"
+		rs.version = ""
+		require.Equal(t, false, rs.IsAvailable())
+	})
+
+	t.Run("When renderer url is set and version is present", func(t *testing.T) {
+		rs.Cfg.RendererUrl = "http://localhost:8081/render"
+		rs.version = "1.0.0"
+		require.Equal(t, true, rs.IsAvailable())
+	})
+
 	t.Run("When renderer responds with correct version should return that version", func(t *testing.T) {
 		server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
 			w.Header().Set("Content-Type", "application/json")