Extra syslog debug (#1030)

* extra logging

pkg/acquisition/modules/syslog/internal/syslogserver.go

@@ -37,6 +37,7 @@ func (s *SyslogServer) Listen(listenAddr string, port int) error {
 	if err != nil {
 		return errors.Wrapf(err, "could not listen on port %d", s.port)
 	}
+	s.Logger.Debugf("listening on %s:%d", s.listenAddr, s.port)
 	s.udpConn = udpConn
 	err = s.udpConn.SetReadBuffer(s.MaxMessageLen) // FIXME probably
 	if err != nil {

pkg/acquisition/modules/syslog/syslog.go

@@ -136,14 +136,19 @@ func (s *SyslogSource) StreamingAcquisition(out chan types.Event, t *tomb.Tomb)
 func (s *SyslogSource) buildLogFromSyslog(ts *time.Time, hostname *string,
 	appname *string, pid *string, msg *string) (string, error) {
 	ret := ""
+	if msg == nil {
+		return "", errors.Errorf("missing message field in syslog message")
+	}
 	if ts != nil {
 		ret += ts.Format("Jan 2 15:04:05")
 	} else {
+		s.logger.Tracef("%s - missing TS", *msg)
 		ret += time.Now().Format("Jan 2 15:04:05")
 	}
 	if hostname != nil {
 		ret += " " + *hostname
 	} else {
+		s.logger.Tracef("%s - missing host", *msg)
 		ret += " unknownhost"
 	}
 	if appname != nil {
@@ -169,8 +174,6 @@ func (s *SyslogSource) buildLogFromSyslog(ts *time.Time, hostname *string,
 	}
 	if msg != nil {
 		ret += *msg
-	} else {
-		return "", errors.Errorf("missing message field in syslog message")
 	}
 	return ret, nil
 
@@ -194,6 +197,7 @@ func (s *SyslogSource) handleSyslogMsg(out chan types.Event, t *tomb.Tomb, c cha
 			var ts time.Time
 
 			logger := s.logger.WithField("client", syslogLine.Client)
+			logger.Tracef("raw: %s", syslogLine)
 			linesReceived.With(prometheus.Labels{"source": syslogLine.Client}).Inc()
 			p := rfc5424.NewParser()
 			m, err := p.Parse(syslogLine.Message)