Add optional syslog logrus hook (#343)

* add optional syslog logrus hook

* document syslog

internal/log/log.go

@@ -22,31 +22,60 @@ import (
 	"bytes"
 	"os"
 
+	"log/syslog"
+
 	"github.com/sirupsen/logrus"
+	lSyslog "github.com/sirupsen/logrus/hooks/syslog"
+	"github.com/spf13/viper"
+	"github.com/superseriousbusiness/gotosocial/internal/config"
 )
 
-// Initialize initializes the global Logrus logger to the specified level
+// Initialize initializes the global Logrus logger, reading the desired
+// log level from the viper store, or using a default if the level
+// has not been set in viper.
+//
 // It also sets the output to log.outputSplitter,
 // so you get error logs on stderr and normal logs on stdout.
-func Initialize(level string) error {
+//
+// If syslog settings are also in viper, then Syslog will be initialized as well.
+func Initialize() error {
 	logrus.SetOutput(&outputSplitter{})
 
-	logLevel, err := logrus.ParseLevel(level)
-	if err != nil {
-		return err
-	}
-	logrus.SetLevel(logLevel)
-
-	if logLevel == logrus.TraceLevel {
-		logrus.SetReportCaller(true)
-	}
-
 	logrus.SetFormatter(&logrus.TextFormatter{
 		DisableColors: true,
 		DisableQuote:  true,
 		FullTimestamp: true,
 	})
 
+	keys := config.Keys
+
+	// check if a desired log level has been set
+	logLevel := viper.GetString(keys.LogLevel)
+	if logLevel != "" {
+		level, err := logrus.ParseLevel(logLevel)
+		if err != nil {
+			return err
+		}
+		logrus.SetLevel(level)
+
+		if level == logrus.TraceLevel {
+			logrus.SetReportCaller(true)
+		}
+	}
+
+	// check if syslog has been enabled, and configure it if so
+	if syslogEnabled := viper.GetBool(keys.SyslogEnabled); syslogEnabled {
+		protocol := viper.GetString(keys.SyslogProtocol)
+		address := viper.GetString(keys.SyslogAddress)
+
+		hook, err := lSyslog.NewSyslogHook(protocol, address, syslog.LOG_INFO, "")
+		if err != nil {
+			return err
+		}
+
+		logrus.AddHook(hook)
+	}
+
 	return nil
 }
 

internal/log/syslog_test.go

@@ -0,0 +1,70 @@
+/*
+   GoToSocial
+   Copyright (C) 2021 GoToSocial Authors admin@gotosocial.org
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package log_test
+
+import (
+	"testing"
+
+	"github.com/sirupsen/logrus"
+	"github.com/spf13/viper"
+	"github.com/stretchr/testify/suite"
+	"github.com/superseriousbusiness/gotosocial/internal/config"
+	"github.com/superseriousbusiness/gotosocial/testrig"
+	"gopkg.in/mcuadros/go-syslog.v2"
+	"gopkg.in/mcuadros/go-syslog.v2/format"
+)
+
+type SyslogTestSuite struct {
+	suite.Suite
+	syslogServer  *syslog.Server
+	syslogChannel chan format.LogParts
+}
+
+func (suite *SyslogTestSuite) SetupTest() {
+	testrig.InitTestConfig()
+
+	viper.Set(config.Keys.SyslogEnabled, true)
+	viper.Set(config.Keys.SyslogProtocol, "udp")
+	viper.Set(config.Keys.SyslogAddress, "localhost:42069")
+	server, channel, err := testrig.InitTestSyslog()
+	if err != nil {
+		panic(err)
+	}
+	suite.syslogServer = server
+	suite.syslogChannel = channel
+
+	testrig.InitTestLog()
+}
+
+func (suite *SyslogTestSuite) TearDownTest() {
+	if err := suite.syslogServer.Kill(); err != nil {
+		panic(err)
+	}
+}
+
+func (suite *SyslogTestSuite) TestSyslog() {
+	logrus.Warn("this is a test of the emergency broadcast system!")
+
+	message := <-suite.syslogChannel
+	suite.Contains(message["content"], "this is a test of the emergency broadcast system!")
+}
+
+func TestSyslogTestSuite(t *testing.T) {
+	suite.Run(t, &SyslogTestSuite{})
+}