JSON Structured logs

[ARobertsCollibra]

Hello Everyone,

I am trying to output logs in a JSON structured format that includes the Key Value Pairs (%kvp).
When I use the normal pattern layout I can get close, but there isn't a good way to convert the KVP to native JSON because the Keys aren't in quotes ". The best I have found is using %replace which can get v1="k1" v2="k2" to v1:"k1",v2:"k2"

<pattern>{"timestamp":"%d{yyyyMMdd HH:mm:ss.SSS}","parameters":[%replace(%replace(%kvp{double}){'=',':'}){'" ','",'}],"message":"%msg"}%n</pattern>

I started looking at the code base to see how hard it would be to support %kvp{json} as an option and came across ch.qos.logback.classic.encoder.JsonEncoder which seems like it would do what I need, but there appears to be zero documentation (at least google doesn't find any) and I can't figure out how to define what fields the encoder outputs.

Any suggestions on the best way to move forward?

Thank you,
Adam

[ceki]

@ARobertsCollibra Hi Adam,

JsonAppendeer is currently being implemented. See commit 9e833ec

This issue is being tracked under LOGBACK-1734

Documentation should follow shortly

[ARobertsCollibra]

Thank you for the quick answer @ceki !

Is there an eta for when LOGBACK-1734 will be released? I ask because if it will take a significant length of time I will continue to look into enhancing the PatternEncoder to support a JSON form for %kvp.

[rajivharris]

Hi @ceki
I want to log only selected fields in the new JsonEncoder. Not able to find documentation or examples.
How can we select fields and customize filed names?
Any help is appreciated.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration>

<configuration>
    <import class="ch.qos.logback.classic.encoder.JsonEncoder" />
    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">    
        <encoder class="ch.qos.logback.classic.encoder.JsonEncoder">
            <!--something like this -->
            <fieldNames>
                <timestamp>timestamp</timestamp>
                <message>message</message>
            </fieldNames>
        </encoder>
               
    </appender>
    <root level="INFO" >        
        <appender-ref ref="STDOUT" />
    </root>

    <logger name="org.springframework" level="INFO" />
    <logger name="org.springframework.web" level="INFO"/>
</configuration>

[ceki]

Some documentation can be found at https://logback.qos.ch/manual/encoders.html#JsonEncoder