we recently migrated our spring boot code from version 2.1.11.RELEASE to 3.3.5, previously when using 2.1.11.RELEASE we were able to print the X-Forwarded-For header value in log using spring-cloud-starter-sleuth by adding the X-Forwarded-For in MDC context as follows:

In bootstrap.yml (2.1.11.RELEASE)

spring:
 sleuth: 
  log:
    slf4j:
      whitelisted-mdc-keys: x-forwarded-for
  propagation-keys: x-forwarded-for

In logback-spring.xml (2.1.11.RELEASE)

<pattern>[%d{yyyy-MM-dd HH:mm:ss.SSS}] %p [${springAppName},%X{X-B3-TraceId:-},%X{X-B3-SpanId:-},%X{x-forwarded-for:-}] %c{3}:[%C{1}:%M:%L] - [%t][%file:%line] - %m%n</pattern>

As a part of migration to spring boot version 3.3.5, same has been replaced by io.micrometer:micrometer-tracing-bridge-brave dependency instead of spring-cloud-starter-sleuth.

In application.yml (3.3.5)

management:
  tracing:
    propagation:
      type: b3
    baggage:
      correlation:
        fields: x-forwarded-for
      remote-fields: x-forwarded-for

In logback-spring.xml (3.3.5)

No change in in logback-spring.xml

I’m able to print all other relevant information from HTTP headers such as X-Forwarded-Host, X-request-id, X-real-ip, etc. in the log by adding the field inside application.yml >> management.tracing.baggage.correlation.fields, management.tracing.baggage.remote-fields and correspondingly whitelisting them in logback-spring.xml >> <pattern></pattern>.

Only challenge is I’m not able to print the X-Forwarded-For