Tempo: Add a feature toggle for Alerting (#106891)

* Add a feature toggle

* Disable alerting when the toggle is switched off

* Update tests

* Update tests

* Update tests

* Simplify ReadPluginJSON as it's used by enterprise

* Update test

* Update test

* Add the toggle check to loader.go

* Move the logic to plugins integration pipeline

pkg/services/pluginsintegration/pipeline/pipeline.go

@@ -6,6 +6,7 @@ import (
 	"github.com/grafana/grafana/pkg/infra/tracing"
 	"github.com/grafana/grafana/pkg/plugins"
 	"github.com/grafana/grafana/pkg/plugins/auth"
+	"github.com/grafana/grafana/pkg/plugins/backendplugin/coreplugin"
 	"github.com/grafana/grafana/pkg/plugins/config"
 	"github.com/grafana/grafana/pkg/plugins/envvars"
 	"github.com/grafana/grafana/pkg/plugins/manager/loader/angular/angularinspector"
@@ -41,9 +42,16 @@ func ProvideDiscoveryStage(cfg *config.PluginManagementCfg, pr registry.Service)
 }
 
 func ProvideBootstrapStage(cfg *config.PluginManagementCfg, sc plugins.SignatureCalculator, a *assetpath.Service) *bootstrap.Bootstrap {
+	disableAlertingForTempoDecorateFunc := func(ctx context.Context, p *plugins.Plugin) (*plugins.Plugin, error) {
+		if p.ID == coreplugin.Tempo && !cfg.Features.TempoAlertingEnabled {
+			p.Alerting = false
+		}
+		return p, nil
+	}
+
 	return bootstrap.New(cfg, bootstrap.Opts{
 		ConstructFunc: bootstrap.DefaultConstructFunc(cfg, sc, a),
-		DecorateFuncs: bootstrap.DefaultDecorateFuncs(cfg),
+		DecorateFuncs: append(bootstrap.DefaultDecorateFuncs(cfg), disableAlertingForTempoDecorateFunc),
 	})
 }
 

pkg/services/pluginsintegration/pluginconfig/config.go

@@ -35,6 +35,7 @@ func ProvidePluginManagementConfig(cfg *setting.Cfg, settingProvider setting.Pro
 			SriChecksEnabled:            features.IsEnabledGlobally(featuremgmt.FlagPluginsSriChecks),
 			PluginsCDNSyncLoaderEnabled: features.IsEnabledGlobally(featuremgmt.FlagPluginsCDNSyncLoader),
 			LocalizationForPlugins:      features.IsEnabledGlobally(featuremgmt.FlagLocalizationForPlugins),
+			TempoAlertingEnabled:        features.IsEnabledGlobally(featuremgmt.FlagTempoAlerting),
 		},
 		cfg.GrafanaComAPIURL,
 		cfg.DisablePlugins,