11.2.4. Creating custom SDATA fields

If you use RFC5424-formatted (IETF-syslog) messages, you can also create custom fields in the SDATA part of the message (For details on the SDATA message part, see Section 2.8.2.3, The STRUCTURED-DATA message part). According to RFC5424, the name of the field (its SD-ID) must not contain the @ character for reserved SD-IDs. Custom SDATA fields must be in the following format: .SDATA.name@<private enterprise number>, for example, .SDATA.mySDATA-field@18372.4. (18372.4 is the private enterprise number of Balabit SA, the developer of syslog-ng OSE.)

Example 11.23. Rewriting custom SDATA fields

The following example sets the sequence ID field of the RFC5424-formatted (IETF-syslog) messages to a fixed value. This field is a predefined SDATA field with a reserved SD-ID, therefore its name does not contain the @ character.

rewrite r_sd {
    set("55555" value(".SDATA.meta.sequenceId"));
};

It is also possible to set the value of a field that does not exist yet, and create a new, custom name-value pair that is associated with the message. The following example creates the .SDATA.groupID.fieldID@18372.4 field and sets its value to yes. If you use the ${.SDATA.groupID.fieldID@18372.4} macro in a template or SQL table, its value will be yes for every message that was processed with this rewrite rule, and empty for every other message.

rewrite r_rewrite_set {
    set("yes" value(".SDATA.groupID.fieldID@18372.4"));
};