From 5c6b913ff1e520cae320913bfee43ec86583b666 Mon Sep 17 00:00:00 2001
From: Jonas Heinrich <Jonas@JonasHeinrich.com>
Date: Thu, 21 Nov 2019 06:21:42 -0800
Subject: [PATCH] logger/gelf: Skip empty lines to comply with spec
The [gelf payload specification](http://docs.graylog.org/en/2.4/pages/gelf.html#gelf-payload-specification)
demands that the field `short_message` *MUST* be set by the client library.
Since docker logging via the gelf driver sends messages line by line, it can happen that messages with an empty
`short_message` are passed on. This causes strict downstream processors (like graylog) to raise an exception.
The logger now skips messages with an empty line.
Resolves: #40232
See also: #37572
Signed-off-by: Jonas Heinrich <Jonas@JonasHeinrich.com>
---
daemon/logger/gelf/gelf.go | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/daemon/logger/gelf/gelf.go b/daemon/logger/gelf/gelf.go
index ab1393cedc..5492e5a4ce 100644
--- a/daemon/logger/gelf/gelf.go
+++ b/daemon/logger/gelf/gelf.go
@@ -166,6 +166,10 @@ func newGELFUDPWriter(address string, info logger.Info) (gelf.Writer, error) {
}
func (s *gelfLogger) Log(msg *logger.Message) error {
+ if len(msg.Line) == 0 {
+ return nil
+ }
+
level := gelf.LOG_INFO
if msg.Source == "stderr" {
level = gelf.LOG_ERR