Adding OkHttp custom interceptor to Feign client

Question

I'm having problems to set up a global OkHttp interceptor for my @FeignClient beans. I'm not experiencing any error, but the interceptor is being ignored.

My understanding is that Spring Cloud's auto configuration should pick the OkHttpClient.Builder bean that I'm declaring and use it to create the underlying OkHttpClient instances, but I might be wrong about this.

Here are the relevant parts of my Spring app:

@SpringBootApplication
@EnableFeignClients(defaultConfiguration = FeignConfig.class)    
@EnableCircuitBreaker
public class MyApp {

    public static void main(String[] args) {
        SpringApplication.run(MyApp.class);
    }
}

---

@Configuration
public class FeignConfig {

    @Bean
    public MyInterceptor myInterceptor() {
        return new MyInterceptor();
    }

    @Bean
    public OkHttpClient.Builder okHttpClientBuilder(MyInterceptor interceptor) {
        return new OkHttpClient.Builder().addInterceptor(interceptor);
    }
}

---

public class MyInterceptor implements okhttp3.Interceptor {

    @Override
    public Response intercept(Chain chain) throws IOException {

        Request request = chain.request();

        System.out.println("Hey there, this is my request: " + request);

        Response response = chain.proceed(request);

        System.out.println("Hey there, this is my response: " + response);

        return response;
    }

}

The intercept method above is never called. I need MyInterceptor to be a Spring bean, because I need to inject other dependencies to it.

---

@FeignClient(name = "myClient", fallback = MyClientFallback.class)
public interface MyClient {

    // method declarations
}

---

@Component
public class MyClientFallback implements MyClient {

    // method fallback implementations
}

---

Here's the relevant part of my application.properties file:

feign.hystrix.enabled = true
feign.okhttp.enabled = true

ribbon.eureka.enabled = false
ribbon.eager-load.enabled = true
ribbon.eager-load.clients = myClient

myClient.ribbon.listOfServers = <IP_LIST>
myClient.ribbon.ServerListRefreshInterval = 10000

---

As you see from the properties declared above, I'm not using Eureka and I'm using Ribbon to load balance my rest client. I'm also using Hystrix to enable fallback responses and I have set the feign.okhttp.enabled property to true.

---

Below is the info about dependecies config and versions...

Spring Boot version is 2.0.3.RELEASE and Spring Cloud version is Finchley.SR1, while OkHttp version is 3.11.0.

In my pom.xml file, I have this spring-cloud-dependencies config:

<dependencyManagement>
    <dependencies>

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-dependencies</artifactId>
            <version>Finchley.SR1</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>

        ...

    </dependencies>
</dependencyManagement>

I have also included the following Spring Boot and Spring Cloud dependencies, along with the OkHttp dependency:

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.0.3.RELEASE</version>
</parent>

<dependencies>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-openfeign</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-ribbon</artifactId>
    </dependency>

    <dependency>
        <groupId>com.squareup.okhttp3</groupId>
        <artifactId>okhttp</artifactId>
        <version>3.11.0</version>
    </dependency>

    ...

</dependencies>

Solution 1

You should provide an OkHttpClient bean as stated in the doc:

The OkHttpClient and ApacheHttpClient feign clients can be used by setting feign.okhttp.enabled or feign.httpclient.enabled to true, respectively, and having them on the classpath. You can customize the HTTP client used by providing a bean of either ClosableHttpClient when using Apache or OkHttpClient whe using OK HTTP.

https://github.com/OpenFeign/feign/blob/master/okhttp/src/main/java/feign/okhttp/OkHttpClient.java

Solution 2

The solution is to let Spring auto configuration do its job.

In order for that to happen, the following dependency must be removed from the pom.xml file:

<dependency>
    <groupId>com.squareup.okhttp3</groupId>
    <artifactId>okhttp</artifactId>
    <version>3.11.0</version>
</dependency>

And the following one must be manually included:

<dependency>
    <groupId>io.github.openfeign</groupId>
    <artifactId>feign-okhttp</artifactId>
</dependency>

Once this is done, everything works as expected with the provided configuration.

Comments

[Mạnh Quyết Nguyễn]

Did you use Feign OkHttpClient? (not the normal OkHttpClient). Also, try to annotated your OkHttpClient with @Primary

[fps]

Your solution is correct, I apologize for my previous comments. The wrapper class feign.okhttp.OkHttpClient was not in the classpath, so Spring auto configuration wasn't being triggered. Once I discovered which dependency I had to include, it´s enough to provide a bean of okhttp3.OkHttpClient.Builder class, as I was doing, and Spring will take care of everything. Thank you very much for your help.

[TheNightsWatch]

Hi Federico, I am facing the same issue. For me request and response to the external service is not printed by following the same code.

[fps]

@TheNightsWatch Hi! I just included that missing dependency and everything worked fine.

[TheNightsWatch]

Ok. instead of <dependency> <groupId>com.squareup.okhttp3</groupId> <artifactId>okhttp</artifactId> <version>3.11.0</version> </dependency> we need to add that dependency? or we need both Okhttp depedencies?

[fps]

@TheNightsWatch I've double checked my app. You only need the <groupId>io.github.openfeign</groupId> <artifactId>feign-okhttp</artifactId> dependency, the <groupId>com.squareup.okhttp3</groupId> <artifactId>okhttp</artifactId> one isn't necessary. Thanks for asking about this, I will edit my answer above.

[min]

Any ways to check if we success "enable" okhttp? it doesn't show okhttp mode on or any obvious info in log

[fps]

@user1686407 Sorry, I don't know if there's some logging message that notifies about enabling okhttp. You can always try to change the log level to TRACE or DEBUG and see what's going on...