improve systemd or docker detection

backend/config/config.go

@@ -79,3 +79,12 @@ func GetDefaultConfig() string {
 func GetEnvApi() string {
 	return os.Getenv("SINGBOX_API")
 }
+
+func IsSystemd() bool {
+	pid := os.Getppid()
+	cmdline, err := os.ReadFile(fmt.Sprintf("/proc/%d/comm", pid))
+	if err != nil {
+		return false
+	}
+	return string(cmdline) == "systemd\n"
+}

backend/logger/logger.go

@@ -3,6 +3,7 @@ package logger
 import (
 	"fmt"
 	"os"
+	"s-ui/config"
 	"time"
 
 	"github.com/op/go-logging"
@@ -22,14 +23,13 @@ func InitLogger(level logging.Level) {
 	var err error
 	var backend logging.Backend
 	var format logging.Formatter
-	ppid := os.Getppid()
 
 	backend, err = logging.NewSyslogBackend("")
 	if err != nil {
 		println("Unable to use syslog: " + err.Error())
 		backend = logging.NewLogBackend(os.Stderr, "", 0)
 	}
-	if ppid > 1 && err != nil {
+	if config.IsSystemd() && err != nil {
 		format = logging.MustStringFormatter(`%{time:2006/01/02 15:04:05} %{level} - %{message}`)
 	} else {
 		format = logging.MustStringFormatter(`%{level} - %{message}`)

backend/service/config.go

@@ -14,6 +14,7 @@ import (
 
 var ApiAddr string
 var LastUpdate int64
+var IsSystemd bool
 
 type ConfigService struct {
 	ClientService
@@ -38,6 +39,7 @@ func NewConfigService() *ConfigService {
 }
 
 func (s *ConfigService) InitConfig() error {
+	IsSystemd = config.IsSystemd()
 	configPath := config.GetBinFolderPath()
 	data, err := os.ReadFile(configPath + "/config.json")
 	if err != nil {

backend/service/server.go

@@ -145,10 +145,9 @@ func (s *ServerService) GetLogs(service string, count string, level string) []st
 	if service == "s-ui" {
 		return logger.GetLogs(c, level)
 	}
-	ppid := os.Getppid()
 	var lines []string
 	var cmdArgs []string
-	if ppid > 1 {
+	if IsSystemd {
 		cmdArgs = []string{"journalctl", "-u", service, "--no-pager", "-n", count, "-p", level}
 	} else {
 		cmdArgs = []string{"tail", "/logs/" + service + ".log", "-n", count}