Change log level of EOF errors in loki.source.syslog (#4590)

Author: dehaansa

CHANGELOG.md

@@ -51,6 +51,8 @@ Main (unreleased)
 
 - Fix direction of arrows for pyroscope components in UI graph. (@dehaansa)
 
+- Only log EOF errors for syslog port investigations in `loki.source.syslog` as Debug, not Warn. (@dehaansa)
+
 v1.11.2
 -----------------
 

internal/component/loki/source/syslog/internal/syslogtarget/transport.go

@@ -331,7 +331,11 @@ func (t *TCPTransport) handleConnection(cn net.Conn) {
 	}, t.maxMessageLength())
 
 	if err != nil {
-		level.Warn(t.logger).Log("msg", "error initializing syslog stream", "err", err)
+		if err == io.EOF {
+			level.Debug(t.logger).Log("msg", "syslog connection closed", "remote", c.RemoteAddr().String())
+		} else {
+			level.Warn(t.logger).Log("msg", "error initializing syslog stream", "err", err)
+		}
 	}
 }