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/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
 }