How could I use structured arguments without using the net.logstash.logback.argument.StructuredArguments class?

[pearj]

So I am using logstash-logback-encoder in a 3rd party product, and in one of the contexts where I am logging, only specific Java classes can be used. The SLF4J API is whitelisted but net.logstash.logback.argument.StructuredArguments is not.

I was thinking that one workaround would be to create a thin wrapper around net.logstash.logback.encoder.LoggingEventCompositeJsonEncoder and modify the Log event on the way through, transforming a specially constructed Map into a StructuredArgument.

I.e. In the Java App, I'd do something like :

logger.info("Some log {}", Map.of("key","value","structured": true))

Then the wrapper would look for any maps in the log event that have structured: true inside them and convert them into a StructuredArgument.

Is there a better way? Perhaps a way that could be done in pure logback.xml instead?

Essentially I want to pre-process the log event, but from my limited research pre-processing logs doesn't seem to be a thing?

[osigida]

I use something like that:
logger.atInfo().addKeyValue("key", "value").log("message: {}", message)

[pearj]

Oh that's interesting, I didn't know about the fluent logging API. I checked the current version of the vendor product we're using and they're still on the 1.7 version of the SLF4J API. However, the next version of the product does use 2.x, and we do have upgrade plans, so this looks like the perfect solution.

So you don't need to provide extra brackets {} for each key value pair?

E.g.

logger.atInfo().addKeyValue("name1", "value1").addKeyValue("name2", "value2").log("message: {} {} {}", message)

Like how the examples work:

logger.info("log message {} {}", keyValue("name1", "value1"), keyValue("name2", "value2")));

Or if you don't provide the brackets does it become a Marker instead of a Structured Argument?

[pearj]

Ahh Key/Value Pairs is just a different feature it doesn't automatically modify the log message too.