Send echo message to graylog2 via GELF TCP 12201 port

Solution 1:

It seems that GELF TCP input needs a null character at the end of each Gelf message.

So you should send:

echo -e '{"version": "1.1","host":"","short_message":"Short message","full_message":"Backtrace here\n\nmore stuff","level":1,"_user_id":9001,"_some_info":"foo","_some_env_var":"bar"}\0' | nc -w 1 my.graylog.server 12201

This answer was found in a discussion on Graylog's issues.

Solution 2:

As I was trying to verify that a Logstash instance was correctly listening for GELF inputs, I've found this thread.

Here is a command that will work for Logstash + Gelf over UDP :

echo '{"version": "1.1","host":"","short_message":"A short message that helps you identify what is going on","full_message":"Backtrace here\n\nmore stuff","level":1,"_user_id":9001,"_some_info":"foo","_some_env_var":"bar"}' | gzip | nc -u -w 1 12201

Notice that :

  • a simple echo is enough, no need for -e
  • the message is gziped, otherwise you'll get this error : Could not find parser for header: [123, 34] in Logstash logs
  • netcat is sending over UDP