[LOG4J2-2136] Add support for values in MDC in JSONLayout KeyValuePairs

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Information Provided
• Affects Version/s: 2.10.0
• Component/s: Layouts
• Labels: extra-field json mdc
• Assignee: Unassigned
• Reporter: Daniel Kirkdorffer
• Created: 29/Nov/17 01:41
• Updated: 29/Nov/17 21:13
• Resolved: 29/Nov/17 06:56

Description

The new KeyValuePair within JSONLayout as implemented for https://issues.apache.org/jira/browse/LOG4J2-1694 doesn't provide support for MDC stored values.

In PatternLayout one can do something like this:

<Pattern>%d{ISO8601}{UTC} %d{Z}{UTC} [CID:%X{conversation-id}] [%t] %-5p %c{1.} - %m%n</Pattern>

But it seems that

<KeyValuePair key="CID" value="%X{conversation-id}"/>

or even

<KeyValuePair key="CID" value="${conversation-id}"/>

doesn't work.

Variable replacement doesn't appear to read from the MDC.