Plugins: Add enablePluginsTracingByDefault feature flag (#80195)

* Add enablePluginsTracingByDefault feature flag

* Enable tracing for all plugins if enablePluginsTracingByDefault is set

* fix docstrings for IsEnabled and IsEnabledGlobally

* fix tests

* do not use separate feature manager

* add test case

* Revert "fix tests"

This reverts commit 46a2420ed1.

* cleanup

* fix plugin tracing disabled if wrong plugin setting is present

* add test case for enabled on plugin with wrong plugin setting but with enablePluginsTracingByDefault feature flag

* Add RequiresRestart = true to enablePluginsTracingByDefault

* re-generate feature flags

* pr review feedback

pkg/plugins/envvars/envvars.go

@@ -14,10 +14,10 @@ import (
 	"github.com/grafana/grafana-plugin-sdk-go/backend"
 	"github.com/grafana/grafana-plugin-sdk-go/backend/proxy"
 	"github.com/grafana/grafana-plugin-sdk-go/experimental/featuretoggles"
-
 	"github.com/grafana/grafana/pkg/plugins"
 	"github.com/grafana/grafana/pkg/plugins/auth"
 	"github.com/grafana/grafana/pkg/plugins/config"
+	"github.com/grafana/grafana/pkg/services/featuremgmt"
 )
 
 const (
@@ -207,8 +207,8 @@ func (s *Service) GetConfigMap(ctx context.Context, pluginID string, _ *auth.Ext
 }
 
 func (s *Service) tracingEnvVars(plugin *plugins.Plugin) []string {
-	var pluginTracingEnabled bool
-	if v, exists := s.cfg.PluginSettings[plugin.ID]["tracing"]; exists {
+	pluginTracingEnabled := s.cfg.Features != nil && s.cfg.Features.IsEnabledGlobally(featuremgmt.FlagEnablePluginsTracingByDefault)
+	if v, exists := s.cfg.PluginSettings[plugin.ID]["tracing"]; exists && !pluginTracingEnabled {
 		pluginTracingEnabled = v == "true"
 	}
 	if !s.cfg.Tracing.IsEnabled() || !pluginTracingEnabled {

pkg/plugins/envvars/envvars_test.go

@@ -354,6 +354,30 @@ func TestInitializer_tracingEnvironmentVariables(t *testing.T) {
 			plugin: defaultPlugin,
 			exp:    expDefaultOtlp,
 		},
+		{
+			name: `enabled on plugin with no "tracing" plugin setting but with enablePluginsTracingByDefault feature flag`,
+			cfg: &config.Cfg{
+				Tracing: config.Tracing{
+					OpenTelemetry: defaultOTelCfg,
+				},
+				PluginSettings: map[string]map[string]string{pluginID: {}},
+				Features:       featuremgmt.WithFeatures(featuremgmt.FlagEnablePluginsTracingByDefault),
+			},
+			plugin: defaultPlugin,
+			exp:    expDefaultOtlp,
+		},
+		{
+			name: `enabled on plugin with plugin setting "tracing=false" but with enablePluginsTracingByDefault feature flag`,
+			cfg: &config.Cfg{
+				Tracing: config.Tracing{
+					OpenTelemetry: defaultOTelCfg,
+				},
+				PluginSettings: map[string]map[string]string{pluginID: {"tracing": "false"}},
+				Features:       featuremgmt.WithFeatures(featuremgmt.FlagEnablePluginsTracingByDefault),
+			},
+			plugin: defaultPlugin,
+			exp:    expDefaultOtlp,
+		},
 		{
 			name: "GF_PLUGIN_VERSION is not present if tracing is disabled",
 			cfg: &config.Cfg{