Merge pull request #154 from friedl/gelf

Gelf doc tutorial

source/tutorials/gelf_forwarding.rst

@@ -0,0 +1,68 @@
+GELF forwarding in rsyslog
+==========================
+
+*Written by Florian Riedl*
+
+Situation
+---------
+
+The current setup has a system with rsyslog as the central syslog server
+and a system with Graylog for storage and analyzing the log messages. 
+Graylog expects the log messages to arrive in GELF (Graylog Extended Log
+Format).
+
+Changing the default log format to GELF
+---------------------------------------
+
+To make rsyslog send GELF we basically need to create a custom template.
+This template will define the format in which the log messages will get 
+sent to Graylog.
+
+::
+
+    template(name="gelf" type="list") {
+        constant(value="{\"version\":\"1.1\",")
+        constant(value="\"host\":\"")
+        property(name="hostname")
+        constant(value="\",\"short_message\":\"")
+        property(name="msg" format="json")
+        constant(value="\",\"timestamp\":\"")
+        property(name="timegenerated" dateformat="unixtimestamp")
+        constant(value="\",\"level\":\"")
+        property(name="syslogseverity")
+        constant(value="\"}")
+    }
+
+This is a typical representation in the list format with all the necessary
+fields and format definitions that Graylog expects.
+
+Applying the template to a syslog action
+----------------------------------------
+
+The next step is applying the template to our output action. Since we
+are forwarding log messages to Graylog, this is usually a syslog sending
+action.
+
+::
+
+    # syslog forwarder via UDP
+    action(type="omfwd" target="graylogserver" port="514" protocol="udp" template="gelf")
+
+We now have a syslog forwarding action. This uses the omfwd module. Please
+note that the case above only works for UDP transport. When using TCP, 
+Graylog expects a Nullbyte as message delimiter. This is currently not 
+possible with rsyslog.
+
+Conclusion
+----------
+
+With this quick and easy setup you can feed Graylog with the correct
+log message format so it can do its work. This case can be applied to
+a lot of different scenarios as well, but with different templates.
+
+This documentation is part of the `rsyslog <http://www.rsyslog.com/>`_
+project.
+
+Copyright © 2008 by `Rainer Gerhards <http://www.gerhards.net/rainer>`_
+and `Adiscon <http://www.adiscon.com/>`_. Released under the GNU GPL
+version 2 or higher.

source/tutorials/index.rst

@@ -12,3 +12,4 @@ Tutorials
    recording_pri
    failover_syslog_server
    log_rotation_fix_size
+   gelf_forwarding