Provides a demo extension to combine different services (#14)

Author: juanpedromoreno

demo/greeting/src/main/proto/echo.proto

@@ -0,0 +1,9 @@
+syntax = "proto3";
+
+import "echo_messages.proto";
+
+package freestyle.rpc.demo;
+
+service EchoService {
+    rpc Echo (EchoRequest) returns (EchoResponse);
+}

demo/greeting/src/main/proto/echo_messages.proto

@@ -0,0 +1,11 @@
+syntax = "proto3";
+
+package freestyle.rpc.demo;
+
+message EchoRequest {
+    string message = 1;
+}
+
+message EchoResponse {
+    string message = 1;
+}

demo/greeting/src/main/scala/greeting/GreetingClientApp.scala

@@ -17,6 +17,14 @@
 package freestyle.rpc.demo
 package greeting
 
+import freestyle.rpc.demo.echo.EchoServiceGrpc
+import freestyle.rpc.demo.echo.EchoServiceGrpc.EchoServiceStub
+import freestyle.rpc.demo.echo_messages.EchoRequest
+import io.grpc.ManagedChannelBuilder
+
+import scala.concurrent.Await
+import scala.concurrent.duration.Duration
+
 object GreetingClientApp {
 
   def main(args: Array[String]): Unit = {
@@ -51,6 +59,21 @@ object GreetingClientApp {
 
     client.biStreamingDemo()
 
+    // EchoDemo using the same server where the greeting service is deployed.
+    echoDemo(EchoRequest("echo..."))
+
     (): Unit
   }
+
+  def echoDemo(request: EchoRequest): Unit = {
+
+    val channel =
+      ManagedChannelBuilder.forAddress(host, portNode1).usePlaintext(true).build
+
+    val asyncEchoClient: EchoServiceStub = EchoServiceGrpc.stub(channel)
+
+    println("")
+    println(s"Received -> ${Await.result(asyncEchoClient.echo(request), Duration.Inf)}")
+    println("")
+  }
 }

demo/greeting/src/main/scala/greeting/runtime/implicits.scala

@@ -19,7 +19,9 @@ package greeting.runtime
 
 import freestyle._
 import freestyle.implicits._
+import freestyle.rpc.demo.echo.EchoServiceGrpc
 import freestyle.rpc.demo.greeting._
+import freestyle.rpc.demo.greeting.service._
 import freestyle.rpc.server._
 import freestyle.rpc.server.implicits._
 import freestyle.rpc.server.handlers._
@@ -32,7 +34,8 @@ object implicits {
   implicit val ec: ExecutionContext = ExecutionContext.Implicits.global
 
   implicit val grpcConfigs: List[GrpcConfig] = List(
-    AddService(GreeterGrpc.bindService(new GreetingService, ec))
+    AddService(GreeterGrpc.bindService(new GreetingService, ec)),
+    AddService(EchoServiceGrpc.bindService(new EchoService, ec))
   )
 
   implicit val grpcServerHandler =

demo/greeting/src/main/scala/greeting/service/EchoService.scala

@@ -0,0 +1,33 @@
+/*
+ * Copyright 2017 47 Degrees, LLC. <http://www.47deg.com>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package freestyle.rpc.demo
+package greeting
+package service
+
+import freestyle.rpc.demo.echo.EchoServiceGrpc
+import freestyle.rpc.demo.echo_messages.{EchoRequest, EchoResponse}
+
+import scala.concurrent.Future
+
+class EchoService extends EchoServiceGrpc.EchoService {
+
+  override def echo(request: EchoRequest): Future[EchoResponse] = {
+    println(s"Echo request ${request.message}")
+    Future.successful(EchoResponse("Server Echo!"))
+  }
+
+}

demo/greeting/src/main/scala/greeting/GreetingService.scala renamed to demo/greeting/src/main/scala/greeting/service/GreetingService.scala

@@ -16,6 +16,7 @@
 
 package freestyle.rpc.demo
 package greeting
+package service
 
 import java.util.concurrent.{Executors, TimeUnit}
 import java.util.concurrent.atomic.AtomicInteger

rpc/src/main/scala/server/package.scala

@@ -27,9 +27,8 @@ package object server {
   class GrpcConfigInterpreter[F[_]](implicit initConfig: Config, configList: List[GrpcConfig])
       extends (Kleisli[F, Server, ?] ~> F) {
 
-    private[this] def interpret(configOptions: List[GrpcConfig])(
-        implicit initConfig: Config): Server =
-      configOptions
+    private[this] def build(configList: List[GrpcConfig]): Server =
+      configList
         .foldLeft[ServerBuilder[_]](ServerBuilder.forPort(initConfig.port))((acc, option) =>
           (option match {
             case DirectExecutor                  => acc.directExecutor()
@@ -45,8 +44,6 @@ package object server {
           }).asInstanceOf[ServerBuilder[_]])
         .build()
 
-    private[this] def build(configList: List[GrpcConfig]): Server = interpret(configList)
-
     override def apply[B](fa: Kleisli[F, Server, B]): F[B] =
       fa(build(configList))