From 03ba91e8a49704262d08b12947ea93d5741c1e06 Mon Sep 17 00:00:00 2001
From: ying-jeanne <74549700+ying-jeanne@users.noreply.github.com>
Date: Mon, 11 Apr 2022 18:50:29 +0200
Subject: [PATCH] add feature toggle with new format (#47336)

* add feature toggle with new format

* fix some comments :heart:

* Update pkg/infra/log/term/terminal_logger.go

Co-authored-by: Emil Tullstedt <emil.tullstedt@grafana.com>

Co-authored-by: Emil Tullstedt <emil.tullstedt@grafana.com>
---
 pkg/infra/log/level/level.go          |  8 ++++
 pkg/infra/log/log.go                  | 63 +++++++++++++++++++++++++--
 pkg/infra/log/term/terminal_logger.go | 21 ++++++---
 3 files changed, 83 insertions(+), 9 deletions(-)

diff --git a/pkg/infra/log/level/level.go b/pkg/infra/log/level/level.go
index cc3ef214491..5b1308d5a17 100644
--- a/pkg/infra/log/level/level.go
+++ b/pkg/infra/log/level/level.go
@@ -196,6 +196,14 @@ var (
 	debugValue = &levelValue{level: levelDebug, name: "dbug"}
 )
 
+func SetLevelKeyAndValuesToGokitLog() {
+	key = "level"
+	errorValue = &levelValue{level: levelError, name: "error"}
+	warnValue = &levelValue{level: levelWarn, name: "warn"}
+	infoValue = &levelValue{level: levelInfo, name: "info"}
+	debugValue = &levelValue{level: levelDebug, name: "debug"}
+}
+
 type level byte
 
 const (
diff --git a/pkg/infra/log/log.go b/pkg/infra/log/log.go
index 21c11705e6a..ea3b824388d 100644
--- a/pkg/infra/log/log.go
+++ b/pkg/infra/log/log.go
@@ -11,6 +11,7 @@ import (
 	"os"
 	"path/filepath"
 	"sort"
+	"strconv"
 	"strings"
 	"sync"
 	"time"
@@ -30,6 +31,7 @@ var (
 	loggersToReload []ReloadableHandler
 	root            *logManager
 	now             = time.Now
+	logTimeFormat   = "2006-01-02T15:04:05.99-0700"
 )
 
 const (
@@ -53,9 +55,10 @@ func init() {
 // logManager manage loggers
 type logManager struct {
 	*ConcreteLogger
-	loggersByName map[string]*ConcreteLogger
-	logFilters    []logWithFilters
-	mutex         sync.RWMutex
+	loggersByName     map[string]*ConcreteLogger
+	logFilters        []logWithFilters
+	mutex             sync.RWMutex
+	gokitLogActivated bool
 }
 
 func newManager(logger gokitlog.Logger) *logManager {
@@ -69,6 +72,12 @@ func (lm *logManager) initialize(loggers []logWithFilters) {
 	lm.mutex.Lock()
 	defer lm.mutex.Unlock()
 
+	if lm.gokitLogActivated {
+		level.SetLevelKeyAndValuesToGokitLog()
+		term.SetTimeFormatGokitLog()
+		logTimeFormat = time.RFC3339Nano
+	}
+
 	defaultLoggers := make([]gokitlog.Logger, len(loggers))
 	for index, logger := range loggers {
 		defaultLoggers[index] = level.NewFilter(logger.val, logger.maxLevel)
@@ -181,7 +190,7 @@ func (cl *ConcreteLogger) Info(msg string, args ...interface{}) {
 }
 
 func (cl *ConcreteLogger) log(msg string, logLevel level.Value, args ...interface{}) error {
-	logger := gokitlog.With(&cl.SwapLogger, "t", gokitlog.TimestampFormat(now, "2006-01-02T15:04:05.99-0700"))
+	logger := gokitlog.With(&cl.SwapLogger, "t", gokitlog.TimestampFormat(now, logTimeFormat))
 	args = append([]interface{}{level.Key(), logLevel, "msg", msg}, args...)
 
 	return logger.Log(args...)
@@ -436,9 +445,55 @@ func ReadLoggingConfig(modes []string, logsPath string, cfg *ini.File) error {
 		configLoggers = append(configLoggers, handler)
 	}
 
+	var err error
+	root.gokitLogActivated, err = isNewLoggerActivated(cfg)
+	if err != nil {
+		return err
+	}
 	if len(configLoggers) > 0 {
 		root.initialize(configLoggers)
 	}
 
 	return nil
 }
+
+// This would be removed eventually, no need to make a fancy design.
+// For the sake of important cycle I just copied the function
+func isNewLoggerActivated(cfg *ini.File) (bool, error) {
+	section := cfg.Section("feature_toggles")
+	toggles, err := readFeatureTogglesFromInitFile(section)
+	if err != nil {
+		return false, err
+	}
+	return toggles["newlog"], nil
+}
+
+func readFeatureTogglesFromInitFile(featureTogglesSection *ini.Section) (map[string]bool, error) {
+	featureToggles := make(map[string]bool, 10)
+
+	// parse the comma separated list in `enable`.
+	featuresTogglesStr := valueAsString(featureTogglesSection, "enable", "")
+	for _, feature := range util.SplitString(featuresTogglesStr) {
+		featureToggles[feature] = true
+	}
+
+	// read all other settings under [feature_toggles]. If a toggle is
+	// present in both the value in `enable` is overridden.
+	for _, v := range featureTogglesSection.Keys() {
+		if v.Name() == "enable" {
+			continue
+		}
+
+		b, err := strconv.ParseBool(v.Value())
+		if err != nil {
+			return featureToggles, err
+		}
+
+		featureToggles[v.Name()] = b
+	}
+	return featureToggles, nil
+}
+
+func valueAsString(section *ini.Section, keyName string, defaultValue string) string {
+	return section.Key(keyName).MustString(defaultValue)
+}
diff --git a/pkg/infra/log/term/terminal_logger.go b/pkg/infra/log/term/terminal_logger.go
index 860ef27c7b6..d98644a87dc 100644
--- a/pkg/infra/log/term/terminal_logger.go
+++ b/pkg/infra/log/term/terminal_logger.go
@@ -14,14 +14,22 @@ import (
 	"github.com/grafana/grafana/pkg/infra/log/level"
 )
 
-const (
+var (
 	timeFormat     = "2006-01-02T15:04:05-0700"
 	termTimeFormat = "01-02|15:04:05"
-	floatFormat    = 'f'
-	termMsgJust    = 40
-	errorKey       = "LOG15_ERROR"
 )
 
+const (
+	floatFormat = 'f'
+	termMsgJust = 40
+	errorKey    = "LOG15_ERROR"
+)
+
+func SetTimeFormatGokitLog() {
+	timeFormat = "2006-01-02T15:04:05.000-0700"
+	termTimeFormat = "01-02|15:04:05.000"
+}
+
 type terminalLogger struct {
 	w io.Writer
 }
@@ -45,7 +53,10 @@ func (l terminalLogger) Log(keyvals ...interface{}) error {
 	r := getRecord(keyvals)
 
 	b := &bytes.Buffer{}
-	lvl := strings.ToUpper(r.level.String())
+
+	// To make the log output more readable, we make all log levels 5 characters long
+	lvl := fmt.Sprintf("%-5s", strings.ToUpper(r.level.String()))
+
 	if r.color > 0 {
 		fmt.Fprintf(b, "\x1b[%dm%s\x1b[0m[%s] %s ", r.color, lvl, r.time.Format(termTimeFormat), r.msg) // lgtm[go/log-injection]
 	} else {