UsageStats: track enabled features (#47407)

* #47127: include enabled features in the usage stats reports

* #47127: convert feature names to snake cased metric names

* #47127: remove dead code

* #47127: lint fix

* #47127: convert GetUsageStats to return `map[string]interface{}`

* #47127: fix testssssssss

* #47127: fix testssssssss

pkg/services/featuremgmt/strcase/snake.go

@@ -0,0 +1,118 @@
+// https://github.com/iancoleman/strcase/blob/master/snake.go
+
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2015 Ian Coleman
+ * Copyright (c) 2018 Ma_124, <github.com/Ma124>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, Subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or Substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package strcase
+
+import (
+	"strings"
+)
+
+// ToSnake converts a string to snake_case
+func ToSnake(s string) string {
+	return ToDelimited(s, '_')
+}
+
+func ToSnakeWithIgnore(s string, ignore string) string {
+	return ToScreamingDelimited(s, '_', ignore, false)
+}
+
+// ToScreamingSnake converts a string to SCREAMING_SNAKE_CASE
+func ToScreamingSnake(s string) string {
+	return ToScreamingDelimited(s, '_', "", true)
+}
+
+// ToKebab converts a string to kebab-case
+func ToKebab(s string) string {
+	return ToDelimited(s, '-')
+}
+
+// ToScreamingKebab converts a string to SCREAMING-KEBAB-CASE
+func ToScreamingKebab(s string) string {
+	return ToScreamingDelimited(s, '-', "", true)
+}
+
+// ToDelimited converts a string to delimited.snake.case
+// (in this case `delimiter = '.'`)
+func ToDelimited(s string, delimiter uint8) string {
+	return ToScreamingDelimited(s, delimiter, "", false)
+}
+
+// ToScreamingDelimited converts a string to SCREAMING.DELIMITED.SNAKE.CASE
+// (in this case `delimiter = '.'; screaming = true`)
+// or delimited.snake.case
+// (in this case `delimiter = '.'; screaming = false`)
+//nolint: gocyclo
+func ToScreamingDelimited(s string, delimiter uint8, ignore string, screaming bool) string {
+	s = strings.TrimSpace(s)
+	n := strings.Builder{}
+	n.Grow(len(s) + 2) // nominal 2 bytes of extra space for inserted delimiters
+	for i, v := range []byte(s) {
+		vIsCap := v >= 'A' && v <= 'Z'
+		vIsLow := v >= 'a' && v <= 'z'
+		if vIsLow && screaming {
+			v += 'A'
+			v -= 'a'
+		} else if vIsCap && !screaming {
+			v += 'a'
+			v -= 'A'
+		}
+
+		// treat acronyms as words, eg for JSONData -> JSON is a whole word
+		if i+1 < len(s) {
+			next := s[i+1]
+			vIsNum := v >= '0' && v <= '9'
+			nextIsCap := next >= 'A' && next <= 'Z'
+			nextIsLow := next >= 'a' && next <= 'z'
+			nextIsNum := next >= '0' && next <= '9'
+			// add underscore if next letter case type is changed
+			if (vIsCap && (nextIsLow || nextIsNum)) || (vIsLow && (nextIsCap || nextIsNum)) || (vIsNum && (nextIsCap || nextIsLow)) {
+				prevIgnore := ignore != "" && i > 0 && strings.ContainsAny(string(s[i-1]), ignore)
+				if !prevIgnore {
+					if vIsCap && nextIsLow {
+						if prevIsCap := i > 0 && s[i-1] >= 'A' && s[i-1] <= 'Z'; prevIsCap {
+							n.WriteByte(delimiter)
+						}
+					}
+					n.WriteByte(v)
+					if vIsLow || vIsNum || nextIsNum {
+						n.WriteByte(delimiter)
+					}
+					continue
+				}
+			}
+		}
+
+		if (v == ' ' || v == '_' || v == '-' || v == '.') && !strings.ContainsAny(string(v), ignore) {
+			// replace space/underscore/hyphen/dot with delimiter
+			n.WriteByte(delimiter)
+		} else {
+			n.WriteByte(v)
+		}
+	}
+
+	return n.String()
+}

pkg/services/featuremgmt/usage_stats.go

@@ -0,0 +1,21 @@
+package featuremgmt
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/grafana/grafana/pkg/services/featuremgmt/strcase"
+)
+
+func (fm *FeatureManager) GetUsageStats(ctx context.Context) map[string]interface{} {
+	enabled := fm.GetEnabled(ctx)
+	stats := make(map[string]interface{}, len(enabled))
+	for featureName := range enabled {
+		stats[asMetricName(featureName)] = 1
+	}
+	return stats
+}
+
+func asMetricName(featureName string) string {
+	return fmt.Sprintf("stats.features.%s.count", strcase.ToSnake(featureName))
+}

pkg/services/featuremgmt/usage_stats_test.go

@@ -0,0 +1,34 @@
+package featuremgmt
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestFeatureUsageStats(t *testing.T) {
+	featureManagerWithAllFeatures := WithFeatures(
+		"trimDefaults",
+		"httpclientprovider_azure_auth",
+		"service-accounts",
+		"database_metrics",
+		"dashboardPreviews",
+		"live-config",
+		"showFeatureFlagsInUI",
+		"UPPER_SNAKE_CASE",
+		"feature.with.a.dot",
+	)
+
+	require.Equal(t, map[string]interface{}{
+		"stats.features.trim_defaults.count":                 1,
+		"stats.features.httpclientprovider_azure_auth.count": 1,
+		"stats.features.service_accounts.count":              1,
+		"stats.features.database_metrics.count":              1,
+		"stats.features.dashboard_previews.count":            1,
+		"stats.features.live_config.count":                   1,
+		"stats.features.show_feature_flags_in_ui.count":      1,
+		"stats.features.upper_snake_case.count":              1,
+		"stats.features.feature_with_a_dot.count":            1,
+	}, featureManagerWithAllFeatures.GetUsageStats(context.Background()))
+}