ClientInterceptor not applied to gRPC Channel

[vladykin]

Describe the bug

I have a problem adding an interceptor to gRPC Channel instantiated by Quarkus.
Here is a minimal reproducer.

package org.acme;

import io.grpc.*;
import io.quarkus.grpc.runtime.annotations.GrpcService;
import io.quarkus.runtime.Startup;
import io.quarkus.runtime.StartupEvent;

import javax.enterprise.event.Observes;
import javax.enterprise.inject.Produces;
import javax.inject.Singleton;

@Startup
public class ExampleApp {

    private static boolean interceptorInstatiated = false;

    public void onStart(@Observes StartupEvent ev,
                        @GrpcService("hello") Channel helloService) {

        System.out.printf("Interceptor instantiated: %s%n", interceptorInstatiated);
    }

    @Produces
    public static ClientInterceptor grpcInterceptor() {
        interceptorInstatiated = true;
        return new ClientInterceptor() {
            @Override
            public <ReqT, RespT> ClientCall<ReqT, RespT> interceptCall(MethodDescriptor<ReqT, RespT> method, CallOptions callOptions, Channel next) {
                return next.newCall(method, callOptions);
            }
        };
    }
}

Expected behavior
I expect ClientInterceptor to be instantiated and registered with Channel. In io.quarkus.grpc.runtime.supports.Channels.createChannel I see code instantiating and adding interceptors. And similar approach works for ServerInterceptor when implementing gRPC server.

Actual behavior
ClientInterceptor is not instantiated.
Program prints: Interceptor instantiated: false

To Reproduce
Steps to reproduce the behavior:

1. Create empty Quarkus project with gRPC extension
2. Paste the ExampleApp class as shown above
3. Run it and see Interceptor instantiated: false

Configuration

# Add your application.properties here, if applicable.
quarkus.grpc.clients.hello.host=localhost
quarkus.grpc.clients.hello.port=50051

Environment (please complete the following information):

• Output of uname -a or ver: Linux laptop 5.4.48-gentoo #1 SMP Sat Jun 27 23:10:36 MSK 2020 x86_64 Intel(R) Core(TM) i7-8850H CPU @ 2.60GHz GenuineIntel GNU/Linux
• Output of java -version:

openjdk version "11.0.6" 2020-01-14 LTS
OpenJDK Runtime Environment Zulu11.37+17-CA (build 11.0.6+10-LTS)
OpenJDK 64-Bit Server VM Zulu11.37+17-CA (build 11.0.6+10-LTS, mixed mode)

• GraalVM version (if different from Java): not using GraalVM
• Quarkus version or git rev: 1.5.2.Final
• Build tool (ie. output of mvnw --version or gradlew --version): Apache Maven 3.6.2

[quarkusbot]

/cc @michalszynkiewicz, @cescoffier

[cescoffier]

Can it be related to the @Startup? Did you try with exposing an @ApplicationScoped bean (as a class) ?

[vladykin]

I tried various scope annotation combinations on the ExampleApp and the grpcInterceptor() method. Also tried extracting interceptor as a separate class:

package org.acme;

import io.grpc.*;

import javax.inject.Singleton;

@Singleton
public class MyInterceptor implements ClientInterceptor {

  public MyInterceptor() {
    ExampleApp.interceptorInstatiated = true;
  }

  @Override
  public <ReqT, RespT> ClientCall<ReqT, RespT> interceptCall(MethodDescriptor<ReqT, RespT> method, CallOptions callOptions, Channel next) {
    return next.newCall(method, callOptions);
  }
}

But it did not help. Interceptor is still not instantiated.

[cescoffier]

So definitely a bug. Thanks for the report, we will look into this.