fix: expose Trojan logs and build metadata

trojan-master/asset/trojan.service

@@ -5,7 +5,7 @@ After=network.target network-online.target nss-lookup.target mysql.service maria
 [Service]
 Type=simple
 StandardError=journal
-ExecStart=/usr/bin/trojan/trojan /usr/local/etc/trojan/config.json
+ExecStart=/bin/sh -c '/usr/bin/trojan/trojan /usr/local/etc/trojan/config.json >> /var/log/trojan.log 2>&1'
 ExecReload=/bin/kill -HUP $MAINPID
 Restart=on-failure
 RestartSec=3s

trojan-master/util/linux.go

@@ -96,7 +96,14 @@ func Log(serviceName string, line int) {
 
 // LogChan 指定服务实时日志, 返回chan
 func LogChan(serviceName, param string, closeChan chan byte) (chan string, error) {
-	cmd := exec.Command("bash", "-c", fmt.Sprintf("journalctl -f -u %s -o cat %s", serviceName, param))
+	logFile := fmt.Sprintf("/var/log/%s.log", serviceName)
+	command := fmt.Sprintf("journalctl -f -u %s -o cat %s", serviceName, param)
+	// docker-systemctl has no persistent journal. Compatibility images write
+	// service output to /var/log/<service>.log instead.
+	if IsExists(logFile) {
+		command = fmt.Sprintf("tail %s -F %s", param, logFile)
+	}
+	cmd := exec.Command("bash", "-c", command)
 
 	stdout, _ := cmd.StdoutPipe()