Styjun

I'm trying to get logging working for each request from a Feign rest client. However I cannot get the logging to work, while 'standard' Slf4j logging does work.

I have the following:

public MyClient() 
 initConnectionProperties();

 this.service = Feign.builder()
 .contract(new JAXRSContract())
 .decoder(getJacksonDecoder())
 .encoder(getJacksonEncoder())


 .requestInterceptor(new BasicAuthRequestInterceptor(user, password))
 //.client(new OkHttpClient())
 .logger(new Slf4jLogger(MyClient.class)) //not working

 .logLevel(feign.Logger.Level.BASIC)
 .target(MyClient.class, this.url);
 logger.info("Connection parameters: url = " + url + ", user = " + user); //Is working
 

You need to configure logging in application.properties as below:

logging.level.<package path>.MyClient=DEBUG

If you're using application.yml then:

logging.level.<package path>.MyClient: DEBUG

The log level can be set to tell Feign how much to log.

Options are:

• NONE, No logging (DEFAULT)


• BASIC, Log only the request method and URL and the response status code and execution time


• HEADERS, Log the basic information along with request and response headers


• FULL, Log the headers, body, and metadata for both requests and responses

Example:

logLevel(feign.Logger.Level.NONE)
or
logLevel(feign.Logger.Level.BASIC)
or
logLevel(feign.Logger.Level.HEADERS)
or
logLevel(feign.Logger.Level.FULL)

For more details, you can refer this

You may also need to configure your log4j logging level for feign to DEBUG. If you are using spring boot, what worked for me is:

curl -X POST http://localhost/loggers/feign -H 'Content-Type: application/json' -d '"configuredLevel": "DEBUG"'

private void setup() 
 //...
 feignBuilder.logger(new MyLogger());
 feignBuilder.logLevel(Logger.Level.FULL);


private static class MyLogger extends Logger 
 @Override
 protected void log(String s, String s1, Object... objects) 
 System.out.println(String.format(s + s1, objects)); // Change me!
 

This is how i was able to log using Custom Config class

Note Feign logging only responds to the DEBUG level.

Config Class

@Configuration
public class UserClientConfig 

 @Bean
 Logger.Level feignLoggerLevel() 
 return Logger.Level.HEADERS;
 
 

Client

@FeignClient(name = "User", url = "http://localhost:8080",configuration=UserClientConfig.class)
public interface UserClient 

 @RequestMapping(method = RequestMethod.GET, value = "/user")
 List<User> getAllUsers(); 

application.properties

logging.level.<pcakgepath>.UserClient: DEBUG