FeatureFlags: Revert managing feature flags outside of settings.Cfg (#44382)

* Revert "FeatureToggles: register all enterprise feature toggles (#44336)"

This reverts commit f53b3fb007.

* Revert "FeatureFlags: manage feature flags outside of settings.Cfg (#43692)"

This reverts commit f94c0decbd.

pkg/setting/provider.go

@@ -132,7 +132,7 @@ func (o *OSSImpl) Section(section string) Section {
 func (OSSImpl) RegisterReloadHandler(string, ReloadHandler) {}
 
 func (o OSSImpl) IsFeatureToggleEnabled(name string) bool {
-	return o.Cfg.IsFeatureToggleEnabled(name)
+	return o.Cfg.FeatureToggles[name]
 }
 
 type keyValImpl struct {

pkg/setting/setting.go

@@ -342,10 +342,8 @@ type Cfg struct {
 
 	ApiKeyMaxSecondsToLive int64
 
-	// Check if a feature toggle is enabled
-	// @deprecated
-	IsFeatureToggleEnabled func(key string) bool // filled in dynamically
-
+	// Use to enable new features which may still be in alpha/beta stage.
+	FeatureToggles       map[string]bool
 	AnonymousEnabled     bool
 	AnonymousOrgName     string
 	AnonymousOrgRole     string
@@ -431,6 +429,41 @@ type Cfg struct {
 	UnifiedAlerting UnifiedAlertingSettings
 }
 
+// IsLiveConfigEnabled returns true if live should be able to save configs to SQL tables
+func (cfg Cfg) IsLiveConfigEnabled() bool {
+	return cfg.FeatureToggles["live-config"]
+}
+
+// IsLiveConfigEnabled returns true if live should be able to save configs to SQL tables
+func (cfg Cfg) IsDashboardPreviesEnabled() bool {
+	return cfg.FeatureToggles["dashboardPreviews"]
+}
+
+// IsTrimDefaultsEnabled returns whether the standalone trim dashboard default feature is enabled.
+func (cfg Cfg) IsTrimDefaultsEnabled() bool {
+	return cfg.FeatureToggles["trimDefaults"]
+}
+
+// IsDatabaseMetricsEnabled returns whether the database instrumentation feature is enabled.
+func (cfg Cfg) IsDatabaseMetricsEnabled() bool {
+	return cfg.FeatureToggles["database_metrics"]
+}
+
+// IsHTTPRequestHistogramDisabled returns whether the request historgrams is disabled.
+// This feature toggle will be removed in Grafana 8.x but gives the operator
+// some graceperiod to update all the monitoring tools.
+func (cfg Cfg) IsHTTPRequestHistogramDisabled() bool {
+	return cfg.FeatureToggles["disable_http_request_histogram"]
+}
+
+func (cfg Cfg) IsNewNavigationEnabled() bool {
+	return cfg.FeatureToggles["newNavigation"]
+}
+
+func (cfg Cfg) IsServiceAccountEnabled() bool {
+	return cfg.FeatureToggles["service-accounts"]
+}
+
 type CommandLineArgs struct {
 	Config   string
 	HomePath string

pkg/setting/setting_feature_toggles.go

@@ -3,23 +3,42 @@ package setting
 import (
 	"strconv"
 
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+
 	"github.com/grafana/grafana/pkg/util"
 	"gopkg.in/ini.v1"
 )
 
-// @deprecated -- should use `featuremgmt.FeatureToggles`
+var (
+	featureToggleInfo = promauto.NewGaugeVec(prometheus.GaugeOpts{
+		Name:      "feature_toggles_info",
+		Help:      "info metric that exposes what feature toggles are enabled or not",
+		Namespace: "grafana",
+	}, []string{"name"})
+
+	defaultFeatureToggles = map[string]bool{
+		"recordedQueries":               false,
+		"accesscontrol":                 false,
+		"service-accounts":              false,
+		"httpclientprovider_azure_auth": false,
+	}
+)
+
 func (cfg *Cfg) readFeatureToggles(iniFile *ini.File) error {
-	section := iniFile.Section("feature_toggles")
-	toggles, err := ReadFeatureTogglesFromInitFile(section)
+	toggles, err := overrideDefaultWithConfiguration(iniFile, defaultFeatureToggles)
 	if err != nil {
 		return err
 	}
-	cfg.IsFeatureToggleEnabled = func(key string) bool { return toggles[key] }
+
+	cfg.FeatureToggles = toggles
+
 	return nil
 }
 
-func ReadFeatureTogglesFromInitFile(featureTogglesSection *ini.Section) (map[string]bool, error) {
-	featureToggles := make(map[string]bool, 10)
+func overrideDefaultWithConfiguration(iniFile *ini.File, featureToggles map[string]bool) (map[string]bool, error) {
+	// Read and populate feature toggles list
+	featureTogglesSection := iniFile.Section("feature_toggles")
 
 	// parse the comma separated list in `enable`.
 	featuresTogglesStr := valueAsString(featureTogglesSection, "enable", "")
@@ -41,5 +60,15 @@ func ReadFeatureTogglesFromInitFile(featureTogglesSection *ini.Section) (map[str
 
 		featureToggles[v.Name()] = b
 	}
+
+	// track if feature toggles are enabled or not using an info metric
+	for k, v := range featureToggles {
+		if v {
+			featureToggleInfo.WithLabelValues(k).Set(1)
+		} else {
+			featureToggleInfo.WithLabelValues(k).Set(0)
+		}
+	}
+
 	return featureToggles, nil
 }

pkg/setting/setting_feature_toggles_test.go

@@ -14,6 +14,7 @@ func TestFeatureToggles(t *testing.T) {
 		conf            map[string]string
 		err             error
 		expectedToggles map[string]bool
+		defaultToggles  map[string]bool
 	}{
 		{
 			name: "can parse feature toggles passed in the `enable` array",
@@ -57,6 +58,18 @@ func TestFeatureToggles(t *testing.T) {
 			expectedToggles: map[string]bool{},
 			err:             strconv.ErrSyntax,
 		},
+		{
+			name: "should override default feature toggles",
+			defaultToggles: map[string]bool{
+				"feature1": true,
+			},
+			conf: map[string]string{
+				"feature1": "false",
+			},
+			expectedToggles: map[string]bool{
+				"feature1": false,
+			},
+		},
 	}
 
 	for _, tc := range testCases {
@@ -68,7 +81,12 @@ func TestFeatureToggles(t *testing.T) {
 			require.ErrorIs(t, err, nil)
 		}
 
-		featureToggles, err := ReadFeatureTogglesFromInitFile(toggles)
+		dt := map[string]bool{}
+		if len(tc.defaultToggles) > 0 {
+			dt = tc.defaultToggles
+		}
+
+		featureToggles, err := overrideDefaultWithConfiguration(f, dt)
 		require.ErrorIs(t, err, tc.err)
 
 		if err == nil {

pkg/setting/setting_unified_alerting.go

@@ -79,7 +79,7 @@ func (cfg *Cfg) readUnifiedAlertingEnabledSetting(section *ini.Section) (*bool,
 	// the unified alerting is not enabled by default. First, check the feature flag
 	if err != nil {
 		// TODO: Remove in Grafana v9
-		if cfg.IsFeatureToggleEnabled("ngalert") {
+		if cfg.FeatureToggles["ngalert"] {
 			cfg.Logger.Warn("ngalert feature flag is deprecated: use unified alerting enabled setting instead")
 			enabled = true
 			// feature flag overrides the legacy alerting setting.

pkg/setting/setting_unified_alerting_test.go

@@ -143,7 +143,6 @@ func TestUnifiedAlertingSettings(t *testing.T) {
 		t.Run(tc.desc, func(t *testing.T) {
 			f := ini.Empty()
 			cfg := NewCfg()
-			cfg.IsFeatureToggleEnabled = func(key string) bool { return false }
 			unifiedAlertingSec, err := f.NewSection("unified_alerting")
 			require.NoError(t, err)
 			for k, v := range tc.unifiedAlertingOptions {