Using ContextualLogging with GELF

[Podnevar]

I'm trying to use contextual logging with Graylog (GELF). The problem i'm having and can't figure it out is how to send this additional fields that I added to context logs. Logging works ok, I see logs on Graylog just no additional fields like it showed with MDC.

What I tried is to use custom ContextDataProvider with creating file under META-INF/services org.apache.logging.log4j.core.util.ContextDataProvider and inserting then io.reactiverse.contextual.logging.VertxContextDataProvider

My log4j2.xml:
<Configuration> <Appenders> <Socket name="GELF" protocol="tcp" host="my.url" port="9850"> <GelfLayout includeStackTrace="true" includeThreadContext="true" includeNullDelimiter="true" compressionType="OFF"> </GelfLayout> </Socket> </Appenders> <Loggers> <Root level="INFO"> <AppenderRef ref="GELF" /> </Root> </Loggers> </Configuration>

How much I tried to debug it seems log4j doesen't pickup this VertxContextDataProvider, could I miss something when creating this file? Is type wrong or what it could be?

[tsegismont]

Can you share a small reproducer project please?

[Podnevar]

Can you share a small reproducer project please?

Here is the recreation of the problem:
https://github.com/Podnevar/contextual-logging-log4j-reactive

[tsegismont]

Sorry for the long delay. I ran socat to simumate GELF target:

socat TCP-LISTEN:9850,reuseaddr,fork STDOUT

Then I changed this in the log4j2 config because the syntax for context map lookup was wrong in console:

Index: src/main/resources/log4j2.xml
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/src/main/resources/log4j2.xml b/src/main/resources/log4j2.xml
--- a/src/main/resources/log4j2.xml	(revision cd29bd79158f6973bafb91db2c79e2c290ecea07)
+++ b/src/main/resources/log4j2.xml	(date 1669042713667)
@@ -10,7 +10,7 @@
 
         <Console name="Console" target="SYSTEM_OUT">
             <PatternLayout>
-                <pattern>%d{HH:mm:ss.SSS} [%thread] [%vcl{requestId}] %-5level %logger{36} - %msg%n</pattern>
+                <pattern>%d{HH:mm:ss.SSS} [%thread] [$${ctx:requestId:-foobar}] %-5level %logger{36} - %msg%n</pattern>
             </PatternLayout>
         </Console>
 
@@ -40,6 +40,7 @@
         </Logger>
         <Root level="INFO">
             <AppenderRef ref="GELF" />
+            <AppenderRef ref="Console" />
         </Root>
     </Loggers>
 </Configuration>

Then I ran the app. In dev mode, indeed the contextual data is not added to the log events (neither to the console or to GELF target). However, if I build the application and then run it:

mvn clean package
java -jar target/quarkus-app/quarkus-run.jar 

Then the contextual data is present in both the console and GELF json message.

So I suspect this is a classloading issue due to the Quarkus dev mode, unrelated to this library.