How to configure spring-cloud-gateway to use sleuth to log request/response body - spring-cloud-sleuth

Question

I am looking to develop a gateway server based on spring-cloud-gateway:2.0.2-RELEASE and would like to utilize sleuth for logging purposes. I have sleuth running since when I write to the log I see the Sleuth details (span Id, etc), but I an hoping to see the body of messages being logged automatically. Is there something I need to do to get Sleuth to log request/response out of the box with Spring-Cloud-Gateway?
Here is the request headers that arrive at my downstream service
headers:
{ 'x-request-foo': '2a9c5e36-2c0f-4ad3-926c-cb20d4428462',
forwarded: 'proto=http;host=localhost;for="0:0:0:0:0:0:0:1:51720"',
'x-forwarded-for': '0:0:0:0:0:0:0:1',
'x-forwarded-proto': 'http',
'x-forwarded-port': '80',
'x-forwarded-host': 'localhost',
'x-b3-traceid': '5bd33eb8050c7a32dfce6adfe68b06ca',
'x-b3-spanid': 'ba202a6d6f3e2893',
'x-b3-parentspanid': 'dfce6adfe68b06ca',
'x-b3-sampled': '0',
host: 'localhost:8080' },
Gradle file in the gateway service..
buildscript {
ext {
kotlinVersion = '1.2.61'
springBootVersion = '2.0.6.RELEASE'
springCloudVersion = 'Finchley.RELEASE'
}
}
dependencyManagement {
imports {
mavenBom "org.springframework.cloud:spring-cloud-sleuth:2.0.2.RELEASE"
mavenBom 'org.springframework.cloud:spring-cloud-gateway:2.0.2.RELEASE'
mavenBom "org.springframework.cloud:spring-cloud-dependencies:${springCloudVersion}"
}
}
dependencies {
implementation('org.springframework.cloud:spring-cloud-starter-sleuth')
implementation('org.springframework.cloud:spring-cloud-starter-gateway')
implementation("org.jetbrains.kotlin:kotlin-stdlib-jdk8")
implementation("org.jetbrains.kotlin:kotlin-reflect")
testImplementation('org.springframework.boot:spring-boot-starter-test')
}
and finally the application.yml file for the gateway service...
server:
servlet:
contextPath: /
port: 80
spring:
application:
name: api.gateway.ben.com
sleuth:
trace-id128: true
sampler:
probability: 1.0
cloud:
gateway:
routes:
- id: admin-ui-2
predicates:
- Path=/admin-ui-2/echo/*
filters:
- SetPath=/fred
- AddRequestHeader=X-Request-Foo, 2a9c5e36-2c0f-4ad3-926c-cb20d4428462
- AddResponseHeader=X-Response-Foo, Bar
uri: http://localhost:8080
logging:
pattern:
level: "[%X{X-B3-TraceId}/%X{X-B3-SpanId}] %-5p [%t] %C{2} - %m%n"
level:
org.springframework.web: DEBUG

Answer 1

Spring Cloud Gateway already can log the request and response, you just need to change your log level to TRACE.
logging:
level:
org.springframework: TRACE
or to be more precise to just log req/resp:
logging:
level:
org.springframework.core.codec.StringDecoder: TRACE
Other option is to use a Filter in Spring Cloud Gateway and log req/resp etc with any loggers like Log4j:
routeBuilder.route(id,
r -> {
return r.path(path).and().method(requestmethod).and()
.header(routmap.getRequestheaderkey(), routmap.getRequestheadervalue()).and()
.readBody(String.class, requestBody -> {
return true;
}).filters(f -> {
f.rewritePath(rewritepathregex, replacement);
f.prefixPath(perfixpath);
f.filter(LogFilter);
return f;
}).uri(uri);
});
This filer "LogFilter" you need to define which would have logging logic.