Redirect STDERR to error log (#709)

* Redirect STDERR to error log

* Add dup2.go

* Redirect error log to log file

---------

Co-authored-by: 杨赫然 <heran.yang@seafile.com>

fileserver/fileserver.go

@@ -27,10 +27,10 @@ import (
 	"github.com/haiwen/seafile-server/fileserver/repomgr"
 	"github.com/haiwen/seafile-server/fileserver/searpc"
 	"github.com/haiwen/seafile-server/fileserver/share"
+	"github.com/haiwen/seafile-server/fileserver/utils"
 	_ "github.com/mattn/go-sqlite3"
 	log "github.com/sirupsen/logrus"
 	"gopkg.in/ini.v1"
-	stdlog "log"
 
 	"net/http/pprof"
 )
@@ -365,6 +365,10 @@ func main() {
 		logFp = fp
 		log.SetOutput(fp)
 	}
+
+	if absLogFile != "" && !logToStdout {
+		utils.Dup(int(logFp.Fd()), int(os.Stderr.Fd()))
+	}
 	// When logFile is "-", use default output (StdOut)
 
 	level, err := log.ParseLevel(option.LogLevel)
@@ -412,9 +416,6 @@ func main() {
 	server.Addr = fmt.Sprintf("%s:%d", option.Host, option.Port)
 	server.Handler = router
 
-	errorLog := stdlog.New(log.StandardLogger().Writer(), "", 0)
-	server.ErrorLog = errorLog
-
 	err = server.ListenAndServe()
 	if err != nil {
 		log.Printf("File server exiting: %v", err)
@@ -453,6 +454,8 @@ func logRotate() {
 		logFp.Close()
 		logFp = fp
 	}
+
+	utils.Dup(int(logFp.Fd()), int(os.Stderr.Fd()))
 }
 
 var rpcclient *searpc.Client

fileserver/utils/dup2.go

@@ -0,0 +1,11 @@
+//go:build !(linux && arm64)
+
+package utils
+
+import (
+	"syscall"
+)
+
+func Dup(from, to int) error {
+	return syscall.Dup2(from, to)
+}

fileserver/utils/dup3.go

@@ -0,0 +1,11 @@
+//go:build linux && arm64
+
+package utils
+
+import (
+	"syscall"
+)
+
+func Dup(from, to int) error {
+	return syscall.Dup3(from, to, 0)
+}

notification-server/dup2.go

@@ -0,0 +1,11 @@
+//go:build !(linux && arm64)
+
+package main
+
+import (
+	"syscall"
+)
+
+func Dup(from, to int) error {
+	return syscall.Dup2(from, to)
+}

notification-server/dup3.go

@@ -0,0 +1,11 @@
+//go:build linux && arm64
+
+package main
+
+import (
+	"syscall"
+)
+
+func Dup(from, to int) error {
+	return syscall.Dup3(from, to, 0)
+}

notification-server/server.go

@@ -20,7 +20,6 @@ import (
 	"github.com/gorilla/websocket"
 	log "github.com/sirupsen/logrus"
 	"gopkg.in/ini.v1"
-	stdlog "log"
 )
 
 var configDir string
@@ -197,6 +196,10 @@ func main() {
 		log.SetOutput(fp)
 	}
 
+	if absLogFile != "" && !logToStdout {
+		Dup(int(logFp.Fd()), int(os.Stderr.Fd()))
+	}
+
 	if err := loadJwtPrivateKey(); err != nil {
 		log.Fatalf("Failed to read config: %v", err)
 	}
@@ -216,8 +219,6 @@ func main() {
 	server.Addr = fmt.Sprintf("%s:%d", host, port)
 	server.Handler = router
 
-	errorLog := stdlog.New(log.StandardLogger().Writer(), "", 0)
-	server.ErrorLog = errorLog
 	err = server.ListenAndServe()
 	if err != nil {
 		log.Infof("notificationserver exiting: %v", err)
@@ -256,6 +257,8 @@ func logRotate() {
 		logFp.Close()
 		logFp = fp
 	}
+
+	Dup(int(logFp.Fd()), int(os.Stderr.Fd()))
 }
 
 func newHTTPRouter() *mux.Router {