gRPC request get client IP

December 29, 2020

What's inside this article ⌄

GRPC get client IP address from request
GRPC client address
GRPC client IP
GRPC request IP

Let’s imagine that we need to get the client’s ip address from the request.

We have a service YourServiceImpl.java:

public class YourServiceImpl extends YourService.YourServiceImplBase {
  @Override 
  public void yourMethod() {
		...
	}
}

And the code for starting the gRPC server GRPCServer.java:

Server server = ServerBuilder
    .forPort(1234)
    .addService(new YourServiceImpl())
    .build();
server.start();
server.awaitTermination();

Let’s create a new class IPInterceptor.java:

class IPInterceptor implements ServerInterceptor {
  @Override
  public <ReqT, RespT> ServerCall.Listener<ReqT> interceptCall(ServerCall<ReqT, RespT> call, Metadata headers, ServerCallHandler<ReqT, RespT> next) {
    String ipAddress = call.getAttributes().get(Grpc.TRANSPORT_ATTR_REMOTE_ADDR).toString();
    log.warn("Client IP address = {}", ipAddress);
    return next.startCall(call, headers);
	}
}

And register a new interceptor in the gRPC server launch code GRPCServer.java:

Server server = ServerBuilder
        .forPort(1234)
        .addService(new YourServiceImpl())
        .intercept(new IPInterceptor())
        .build();
server.start();
server.awaitTermination();

Done. If you need to pass the ip address from the interceptor to the YourServiceImpl service, then read this article.