feat (cli): Introduce --server (still un-tested & un-documented)

cli/src/main/java/dev/enola/cli/CommandWithModel.java

@@ -19,10 +19,12 @@
 
 import dev.enola.common.io.resource.ResourceProviders;
 import dev.enola.core.EnolaServiceProvider;
+import dev.enola.core.grpc.EnolaGrpcClientProvider;
 import dev.enola.core.grpc.EnolaGrpcInProcess;
 import dev.enola.core.meta.EntityKindRepository;
 import dev.enola.core.proto.EnolaServiceGrpc.EnolaServiceBlockingStub;
 
+import picocli.CommandLine.ArgGroup;
 import picocli.CommandLine.Model.CommandSpec;
 import picocli.CommandLine.Option;
 import picocli.CommandLine.Spec;
@@ -36,24 +38,28 @@ public abstract class CommandWithModel implements CheckedRunnable {
     protected EnolaServiceProvider esp;
     @Spec CommandSpec spec;
 
-    @Option(
-            names = {"--model"},
-            required = true,
-            description = "URI to EntityKinds (e.g. file:model.yaml)")
-    private URI model;
+    @ArgGroup(multiplicity = "1")
+    ModelOrServer group;
 
     private EnolaServiceBlockingStub service;
 
     @Override
     public final void run() throws Exception {
         out = spec.commandLine().getOut();
 
+        // TODO Fix design; as-is, this may stay null if --server instead of --model is used
+        EntityKindRepository ekr = null;
+
         // TODO Move elsewhere for continuous ("shell") mode, as this is "expensive".
-        var modelResource = new ResourceProviders().getReadableResource(model);
-        var ekr = new EntityKindRepository();
-        ekr.load(modelResource);
-        esp = new EnolaServiceProvider();
-        service = new EnolaGrpcInProcess(esp.get(ekr)).getClient();
+        if (group.model != null) {
+            var modelResource = new ResourceProviders().getReadableResource(group.model);
+            ekr = new EntityKindRepository();
+            ekr.load(modelResource);
+            esp = new EnolaServiceProvider();
+            service = new EnolaGrpcInProcess(esp.get(ekr)).get();
+        } else if (group.server != null) {
+            service = new EnolaGrpcClientProvider(group.server).get();
+        }
 
         run(ekr, service);
     }
@@ -62,4 +68,19 @@ public final void run() throws Exception {
     // here
     protected abstract void run(EntityKindRepository ekr, EnolaServiceBlockingStub service)
             throws Exception;
+
+    static class ModelOrServer {
+
+        @Option(
+                names = {"--model"},
+                required = true,
+                description = "URI to EntityKinds (e.g. file:model.yaml)")
+        private URI model;
+
+        @Option(
+                names = {"--server"},
+                required = true,
+                description = "Target of an Enola gRPC Server (e.g. localhost:7070)")
+        private String server;
+    }
 }

core/impl/src/main/java/dev/enola/core/grpc/EnolaGrpcClientProvider.java

@@ -0,0 +1,47 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Copyright 2023 The Enola <https://enola.dev> Authors
+ *
+ * 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
+ *
+ *     https://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 dev.enola.core.grpc;
+
+import static java.util.concurrent.TimeUnit.SECONDS;
+
+import dev.enola.core.proto.EnolaServiceGrpc;
+
+import io.grpc.Grpc;
+import io.grpc.InsecureChannelCredentials;
+import io.grpc.ManagedChannel;
+
+public class EnolaGrpcClientProvider
+        implements AutoCloseable { // javax.inject.Provider<EnolaServiceGrpc.EnolaServiceBlockingStub>
+
+    private final EnolaServiceGrpc.EnolaServiceBlockingStub client;
+    private final ManagedChannel channel;
+
+    public EnolaGrpcClientProvider(String endpoint) {
+        var credz = InsecureChannelCredentials.create();
+        channel = Grpc.newChannelBuilder(endpoint, credz).build();
+        client = EnolaServiceGrpc.newBlockingStub(channel).withDeadlineAfter(3, SECONDS);
+    }
+
+    public EnolaServiceGrpc.EnolaServiceBlockingStub get() {
+        return client;
+    }
+
+    public void close() throws Exception {
+        channel.shutdownNow().awaitTermination(3, SECONDS);
+    }
+}

core/impl/src/main/java/dev/enola/core/grpc/EnolaGrpcInProcess.java

@@ -28,7 +28,8 @@
 import java.io.IOException;
 import java.util.concurrent.TimeUnit;
 
-public class EnolaGrpcInProcess implements AutoCloseable {
+public class EnolaGrpcInProcess
+        implements AutoCloseable { // javax.inject.Provider<EnolaServiceGrpc.EnolaServiceBlockingStub>
 
     private final EnolaService service;
     private final Server server;
@@ -46,10 +47,11 @@ public EnolaGrpcInProcess(EnolaService service) throws IOException {
         channelBuilder.directExecutor(); // as above
         channel = channelBuilder.build();
 
+        // .withDeadlineAfter(13, SECONDS) doesn't seem to work will with InProcessChannelBuilder?!
         client = EnolaServiceGrpc.newBlockingStub(channel);
     }
 
-    public EnolaServiceGrpc.EnolaServiceBlockingStub getClient() {
+    public EnolaServiceGrpc.EnolaServiceBlockingStub get() {
         return client;
     }
 

core/impl/src/main/java/dev/enola/core/grpc/EnolaGrpcServer.java

@@ -22,6 +22,7 @@
 import io.grpc.ServerBuilder;
 
 import java.io.IOException;
+import java.util.concurrent.TimeUnit;
 
 public class EnolaGrpcServer implements AutoCloseable {
 
@@ -46,7 +47,7 @@ public int getPort() {
     }
 
     @Override
-    public void close() throws Exception {
-        server.shutdown().awaitTermination();
+    public void close() throws InterruptedException {
+        server.shutdown().awaitTermination(7, TimeUnit.SECONDS);
     }
 }

core/impl/src/test/java/dev/enola/core/grpc/EnolaGrpcServerTest.java

@@ -19,8 +19,6 @@
 
 import static com.google.common.truth.Truth.assertThat;
 
-import static java.util.concurrent.TimeUnit.SECONDS;
-
 import dev.enola.common.io.resource.ClasspathResource;
 import dev.enola.core.EnolaService;
 import dev.enola.core.EnolaServiceProvider;
@@ -29,10 +27,6 @@
 import dev.enola.core.proto.GetEntityRequest;
 import dev.enola.core.proto.ID;
 
-import io.grpc.Grpc;
-import io.grpc.InsecureChannelCredentials;
-import io.grpc.ManagedChannel;
-
 import org.junit.Test;
 
 public class EnolaGrpcServerTest {
@@ -43,17 +37,16 @@ public void remoting() throws Exception {
             // similarly in dev.enola.demo.ServerTest
             var port = enolaServer.getPort();
             var endpoint = "localhost:" + port;
-            var credz = InsecureChannelCredentials.create();
-            ManagedChannel channel = Grpc.newChannelBuilder(endpoint, credz).build();
-            check(EnolaServiceGrpc.newBlockingStub(channel).withDeadlineAfter(3, SECONDS));
-            channel.shutdownNow().awaitTermination(3, SECONDS);
+            try (var enolaClient = new EnolaGrpcClientProvider(endpoint)) {
+                check(enolaClient.get());
+            }
         }
     }
 
     @Test
     public void inProcess() throws Exception {
         try (var enolaServer = new EnolaGrpcInProcess(service())) {
-            check(enolaServer.getClient());
+            check(enolaServer.get());
         }
     }
 

web/rest/src/test/java/dev/enola/web/rest/RestTest.java

@@ -44,7 +44,7 @@ public void getAndList() throws IOException {
         var addr = new InetSocketAddress(0);
         try (var server = new SunServer(addr)) {
             // Setup
-            var testGrpcService = new EnolaGrpcInProcess(new TestService()).getClient();
+            var testGrpcService = new EnolaGrpcInProcess(new TestService()).get();
             new RestAPI(testGrpcService).register(server);
             server.start();
             var rp = new ResourceProviders();

web/ui-soy/src/test/java/dev/enola/web/ui/UiTest.java

@@ -42,7 +42,7 @@ public class UiTest {
     public void testUi() throws IOException {
         var addr = new InetSocketAddress(0);
         try (var server = new SunServer(addr)) {
-            var testGrpcService = new EnolaGrpcInProcess(new TestService()).getClient();
+            var testGrpcService = new EnolaGrpcInProcess(new TestService()).get();
             new UI(testGrpcService).register(server);
             server.start();
             var rp = new ResourceProviders();