netty: return status code unavailable when netty channel has unresolved InetSocketAddress (#7023)

netty/src/main/java/io/grpc/netty/NettyChannelBuilder.java

@@ -103,7 +103,8 @@ public final class NettyChannelBuilder
    * Creates a new builder with the given server address. This factory method is primarily intended
    * for using Netty Channel types other than SocketChannel. {@link #forAddress(String, int)} should
    * generally be preferred over this method, since that API permits delaying DNS lookups and
-   * noticing changes to DNS.
+   * noticing changes to DNS. If an unresolved InetSocketAddress is passed in, then it will remain
+   * unresolved.
    */
   @CheckReturnValue
   public static NettyChannelBuilder forAddress(SocketAddress serverAddress) {

netty/src/main/java/io/grpc/netty/Utils.java

@@ -54,6 +54,7 @@ import io.netty.util.concurrent.DefaultThreadFactory;
 import java.io.IOException;
 import java.lang.reflect.Constructor;
 import java.nio.channels.ClosedChannelException;
+import java.nio.channels.UnresolvedAddressException;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.concurrent.ThreadFactory;
@@ -270,6 +271,9 @@ class Utils {
     if (t instanceof IOException) {
       return Status.UNAVAILABLE.withDescription("io exception").withCause(t);
     }
+    if (t instanceof UnresolvedAddressException) {
+      return Status.UNAVAILABLE.withDescription("unresolved address").withCause(t);
+    }
     if (t instanceof Http2Exception) {
       return Status.INTERNAL.withDescription("http2 exception").withCause(t);
     }

netty/src/test/java/io/grpc/netty/NettyTransportTest.java

@@ -16,16 +16,24 @@
 
 package io.grpc.netty;
 
+import static com.google.common.truth.Truth.assertThat;
+import static org.junit.Assert.assertEquals;
+
+import com.google.common.util.concurrent.SettableFuture;
+import io.grpc.ChannelLogger;
 import io.grpc.ServerStreamTracer;
+import io.grpc.Status;
 import io.grpc.internal.AbstractTransportTest;
 import io.grpc.internal.ClientTransportFactory;
 import io.grpc.internal.FakeClock;
 import io.grpc.internal.InternalServer;
 import io.grpc.internal.ManagedClientTransport;
 import java.net.InetSocketAddress;
+import java.nio.channels.UnresolvedAddressException;
 import java.util.List;
 import java.util.concurrent.TimeUnit;
 import org.junit.After;
+import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
 
@@ -106,4 +114,47 @@ public class NettyTransportTest extends AbstractTransportTest {
   public void clientChecksInboundMetadataSize_trailer() throws Exception {
     // Server-side is flaky due to https://github.com/netty/netty/pull/8332
   }
+
+  @Test
+  public void channelHasUnresolvedHostname() throws Exception {
+    server = null;
+    final SettableFuture<Status> future = SettableFuture.create();
+    ChannelLogger logger = transportLogger();
+    ManagedClientTransport transport = clientFactory.newClientTransport(
+        InetSocketAddress.createUnresolved("invalid", 1234),
+        new ClientTransportFactory.ClientTransportOptions()
+            .setChannelLogger(logger), logger);
+    Runnable runnable = transport.start(new ManagedClientTransport.Listener() {
+      @Override
+      public void transportShutdown(Status s) {
+        future.set(s);
+      }
+
+      @Override
+      public void transportTerminated() {}
+
+      @Override
+      public void transportReady() {
+        Throwable t = new Throwable("transport should have failed and shutdown but didnt");
+        future.setException(t);
+      }
+
+      @Override
+      public void transportInUse(boolean inUse) {
+        Throwable t = new Throwable("transport should have failed and shutdown but didnt");
+        future.setException(t);
+      }
+    });
+    if (runnable != null) {
+      runnable.run();
+    }
+    try {
+      Status status = future.get();
+      assertEquals(Status.Code.UNAVAILABLE, status.getCode());
+      assertThat(status.getCause()).isInstanceOf(UnresolvedAddressException.class);
+      assertEquals("unresolved address", status.getDescription());
+    } finally {
+      transport.shutdown(Status.UNAVAILABLE.withDescription("test shutdown"));
+    }
+  }
 }

netty/src/test/java/io/grpc/netty/UtilsTest.java

@@ -42,6 +42,7 @@ import io.netty.handler.codec.http2.Http2Error;
 import io.netty.handler.codec.http2.Http2Exception;
 import io.netty.handler.codec.http2.Http2Headers;
 import io.netty.util.AsciiString;
+import java.nio.channels.UnresolvedAddressException;
 import java.util.Map;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -61,6 +62,8 @@ public class UtilsTest {
     Throwable t;
     t = new ConnectTimeoutException("msg");
     assertStatusEquals(Status.UNAVAILABLE.withCause(t), Utils.statusFromThrowable(t));
+    t = new UnresolvedAddressException();
+    assertStatusEquals(Status.UNAVAILABLE.withCause(t), Utils.statusFromThrowable(t));
     t = new Http2Exception(Http2Error.INTERNAL_ERROR, "msg");
     assertStatusEquals(Status.INTERNAL.withCause(t), Utils.statusFromThrowable(t));
     t = new Exception("msg");