JSON/CEE Structured Content Extraction Module (mmjsonparse)ΒΆ

Module Name:    mmjsonparse

Available since:6.6.0+

Author:Rainer Gerhards <rgerhards@adiscon.com>

Description:

This module provides support for parsing structured log messages that follow the CEE/lumberjack spec. The so-called “CEE cookie” is checked and, if present, the JSON-encoded structured message content is parsed. The properties are then available as original message properties.

The “CEE cookie” is the character squence “@cee:” which must prepend the actual JSON. Note that the JSON must be valid and MUST NOT be followed by any non-JSON message. If either of these conditions is not true, mmjsonparse will not parse the associated JSON. This is based on the cookie definition used in CEE/project lumberjack and is meant to aid against an erroneous detection of a message as being CEE where it is not.

This also means that mmjsonparse currently is NOT a generic JSON parser that picks up JSON from whereever it may occur in the message. This is intentional, but future versions may support config parameters to relax the format requirements.

Action specific Configuration Directives:

  • cookie [string] defaults to “@cee:”

    Permits to set the cookie that must be present in front of the JSON part of the message.

    Most importantly, this can be set to the empty string (“”) in order to not require any cookie. In this case, leading spaces are permitted in front of the JSON. No non-whitespace characters are permitted after the JSON. If such is required, mmnormalize must be used.

Sample:

This activates the module and applies normalization to all messages:

module(load="mmjsonparse")
action(type="mmjsonparse")

To permit parsing messages without cookie, use this action statement:

action(type="mmjsonparse" cookie="")

The same in legacy format:

$ModLoad mmjsonparse
*.* :mmjsonparse: