From 941d84fb3f9f4663dacb887d3d6134b8e8ed6a05 Mon Sep 17 00:00:00 2001
From: Bruno Clermont <bruno@robotinfra.com>
Date: Wed, 8 Feb 2017 18:26:03 +0800
Subject: [PATCH] switch to logrus

---
 src/cypherpunks.ru/govpn/logger.go | 111 +++++++++++++++++++++++------
 1 file changed, 89 insertions(+), 22 deletions(-)

diff --git a/src/cypherpunks.ru/govpn/logger.go b/src/cypherpunks.ru/govpn/logger.go
index f38a245..967b843 100644
--- a/src/cypherpunks.ru/govpn/logger.go
+++ b/src/cypherpunks.ru/govpn/logger.go
@@ -1,3 +1,5 @@
+// +build !windows
+
 /*
 GoVPN -- simple secure free software virtual private network daemon
 Copyright (C) 2014-2017 Sergey Matveev <stargrave@stargrave.org>
@@ -20,37 +22,102 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 package govpn
 
 import (
-	"log"
-	"log/syslog"
-)
+	"bytes"
+	"fmt"
+	logsyslog "log/syslog"
+	"os"
+	"sort"
+	"time"
 
-var (
-	sysloger *log.Logger
+	"github.com/Sirupsen/logrus"
+	"github.com/Sirupsen/logrus/hooks/syslog"
+	"github.com/pkg/errors"
 )
 
-// Enable logging to syslog, instead of default stdout log.
-func SyslogEnable() {
-	var err error
-	sysloger, err = syslog.NewLogger(syslog.LOG_INFO, 0)
-	if err != nil {
-		log.Fatalln(err)
+// syslogFormatter is a formatter that is syslog friendly
+type syslogFormatter struct {
+}
+
+// Format convert a log entry into a list of bytes
+func (sf *syslogFormatter) Format(entry *logrus.Entry) ([]byte, error) {
+	buf := bytes.NewBuffer(nil)
+	var (
+		err   error
+		index int
+	)
+	keys := make([]string, len(entry.Data))
+	for k := range entry.Data {
+		keys[index] = k
+		index++
+	}
+	sort.Strings(keys)
+
+	for index = range keys {
+		k := keys[index]
+		v := entry.Data[k]
+		if _, err = buf.WriteString(fmt.Sprintf("[%s]%+v ", k, v)); err != nil {
+			return nil, errors.Wrapf(err, "buf.WriteString %s", k)
+		}
 	}
+	if _, err = buf.WriteString(entry.Message); err != nil {
+		return nil, errors.Wrap(err, "buf.WriteString message")
+	}
+	return buf.Bytes(), nil
 }
 
-// Call either syslog-related logger.Printf if SyslogEnabled,
-// default log.Printf otherwise.
-func Printf(f string, v ...interface{}) {
-	if sysloger == nil {
-		log.Printf(f, v...)
+// NewLogger return a logger for specified level. Syslog or Windows Events can be turned on.
+func NewLogger(level string, syslog bool) (*logrus.Logger, error) {
+	var logger *logrus.Logger
+	logLevel, err := logrus.ParseLevel(level)
+	if err != nil {
+		return nil, errors.Wrap(err, "logrus.ParseLevel")
+	}
+
+	if syslog {
+		syslogHook, err := logrus_syslog.NewSyslogHook("", "", logsyslog.LOG_INFO, "GoVPN")
+		if err != nil {
+			return nil, errors.Wrap(err, "logrus_syslog.NewSyslogHook")
+		}
+		logger = &logrus.Logger{
+			Formatter: &syslogFormatter{},
+			Hooks:     make(logrus.LevelHooks),
+		}
+		logger.Hooks.Add(syslogHook)
 	} else {
-		sysloger.Printf(f, v...)
+		logger = &logrus.Logger{
+			Formatter: &logrus.TextFormatter{
+				ForceColors:      true,
+				DisableColors:    false,
+				DisableTimestamp: false,
+				FullTimestamp:    true,
+				TimestampFormat:  time.RFC3339Nano,
+				DisableSorting:   false,
+			},
+			Hooks: make(logrus.LevelHooks),
+		}
+	}
+	logger.Out = os.Stderr
+	logger.Level = logLevel
+	logger.WithFields(logrus.Fields{
+		"version": VersionGet(),
+		"level":   logLevel.String(),
+	}).Info("Initialize logging")
+	return logger, nil
+}
+
+// ExtendLogFields add to existing fields a new batch of log Fields
+func ExtendLogFields(input *logrus.Fields, add logrus.Fields) {
+	i := *input
+	for k, v := range add {
+		i[k] = v
 	}
 }
 
-// Call both default log.Printf and syslog-related one.
-func BothPrintf(f string, v ...interface{}) {
-	log.Printf(f, v...)
-	if sysloger != nil {
-		sysloger.Printf(f, v...)
+// MergeLogFields combine multiple log fields into a single one
+func MergeLogFields(fields ...logrus.Fields) (output logrus.Fields) {
+	output = logrus.Fields{}
+	for _, f := range fields {
+		ExtendLogFields(&output, f)
 	}
+	return
 }
-- 
2.44.0