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/services/featuremgmt/service.go

@@ -1,95 +0,0 @@
-package featuremgmt
-
-import (
-	"fmt"
-	"os"
-	"path/filepath"
-
-	"github.com/grafana/grafana/pkg/infra/log"
-
-	"github.com/grafana/grafana/pkg/models"
-	"github.com/grafana/grafana/pkg/setting"
-	"github.com/prometheus/client_golang/prometheus"
-	"github.com/prometheus/client_golang/prometheus/promauto"
-)
-
-var (
-	// The values are updated each time
-	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"})
-)
-
-func ProvideManagerService(cfg *setting.Cfg, licensing models.Licensing) (*FeatureManager, error) {
-	mgmt := &FeatureManager{
-		isDevMod:  setting.Env != setting.Prod,
-		licensing: licensing,
-		flags:     make(map[string]*FeatureFlag, 30),
-		enabled:   make(map[string]bool),
-		log:       log.New("featuremgmt"),
-	}
-
-	// Register the standard flags
-	mgmt.registerFlags(standardFeatureFlags...)
-
-	// Load the flags from `custom.ini` files
-	flags, err := setting.ReadFeatureTogglesFromInitFile(cfg.Raw.Section("feature_toggles"))
-	if err != nil {
-		return mgmt, err
-	}
-	for key, val := range flags {
-		flag, ok := mgmt.flags[key]
-		if !ok {
-			flag = &FeatureFlag{
-				Name:  key,
-				State: FeatureStateUnknown,
-			}
-			mgmt.flags[key] = flag
-		}
-		flag.Expression = fmt.Sprintf("%t", val) // true | false
-	}
-
-	// Make sure enterprise features are registered
-	for key, val := range licensing.EnabledFeatures() {
-		f, ok := mgmt.flags[key]
-		if ok {
-			f.RequiresLicense = true
-			if f.Expression == "" {
-				f.Expression = "true"
-			}
-		} else if val {
-			mgmt.registerFlags(FeatureFlag{
-				Name:            key,
-				RequiresLicense: true,
-				Expression:      "true",
-			})
-		}
-	}
-
-	// Load config settings
-	configfile := filepath.Join(cfg.HomePath, "conf", "features.yaml")
-	if _, err := os.Stat(configfile); err == nil {
-		mgmt.log.Info("[experimental] loading features from config file", "path", configfile)
-		mgmt.config = configfile
-		err = mgmt.readFile()
-		if err != nil {
-			return mgmt, err
-		}
-	}
-
-	// update the values
-	mgmt.update()
-
-	// Minimum approach to avoid circular dependency
-	cfg.IsFeatureToggleEnabled = mgmt.IsEnabled
-	return mgmt, nil
-}
-
-// ProvideToggles allows read-only access to the feature state
-func ProvideToggles(mgmt *FeatureManager) *FeatureToggles {
-	return &FeatureToggles{
-		manager: mgmt,
-	}
-}