core,netty: expose listening on multiple ports

core/src/main/java/io/grpc/Server.java

@@ -17,6 +17,7 @@
 package io.grpc;
 
 import java.io.IOException;
+import java.net.SocketAddress;
 import java.util.Collections;
 import java.util.List;
 import java.util.concurrent.TimeUnit;
@@ -41,8 +42,10 @@ public abstract class Server {
   /**
    * Returns the port number the server is listening on.  This can return -1 if there is no actual
    * port or the result otherwise does not make sense.  Result is undefined after the server is
-   * terminated.
+   * terminated.  If there are multiple possible ports, this will return one arbitrarily.
+   * Implementations are encouraged to return the same port on each call.
    *
+   * @see #getListenSockets()
    * @throws IllegalStateException if the server has not yet been started.
    * @since 1.0.0
    */
@@ -50,6 +53,19 @@ public abstract class Server {
     return -1;
   }
 
+  /**
+   * Returns a list of listening sockets for this server.  May be different than the originally
+   * requested sockets (e.g. listening on port '0' may end up listening on a different port).
+   * The list is unmodifiable.
+   *
+   * @throws IllegalStateException if the server has not yet been started.
+   * @since 1.19.0
+   */
+  @ExperimentalApi("https://github.com/grpc/grpc-java/issues/FIXME")
+  public List<? extends SocketAddress> getListenSockets() {
+    throw new UnsupportedOperationException();
+  }
+
   /**
    * Returns all services registered with the server, or an empty list if not supported by the
    * implementation.

core/src/main/java/io/grpc/inprocess/InProcessServer.java

@@ -27,6 +27,7 @@ import io.grpc.internal.ObjectPool;
 import io.grpc.internal.ServerListener;
 import io.grpc.internal.ServerTransportListener;
 import java.io.IOException;
+import java.net.SocketAddress;
 import java.util.Collections;
 import java.util.List;
 import java.util.concurrent.ConcurrentHashMap;
@@ -77,13 +78,13 @@ final class InProcessServer implements InternalServer {
   }
 
   @Override
-  public int getPort() {
+  public SocketAddress getListenSocketAddress() {
-    return -1;
+    return new InProcessSocketAddress(name);
   }
 
   @Override
-  public List<InternalInstrumented<SocketStats>> getListenSockets() {
+  public InternalInstrumented<SocketStats> getListenSocketStats() {
-    return Collections.emptyList();
+    return null;
   }
 
   @Override

core/src/main/java/io/grpc/internal/InternalServer.java

@@ -19,7 +19,8 @@ package io.grpc.internal;
 import io.grpc.InternalChannelz.SocketStats;
 import io.grpc.InternalInstrumented;
 import java.io.IOException;
-import java.util.List;
+import java.net.SocketAddress;
+import javax.annotation.Nullable;
 import javax.annotation.concurrent.ThreadSafe;
 
 /**
@@ -46,13 +47,13 @@ public interface InternalServer {
   void shutdown();
 
   /**
-   * Returns what underlying port the server is listening on, or -1 if the port number is not
+   * Returns the listening socket address.  May change after {@link start(ServerListener)} is
-   * available or does not make sense.
+   * called.
    */
-  int getPort();
+  SocketAddress getListenSocketAddress();
 
   /**
-   * Returns the listen sockets of this server. May return an empty list but never returns null.
+   * Returns the listen socket stats of this server. May return {@code null}.
    */
-  List<InternalInstrumented<SocketStats>> getListenSockets();
+  @Nullable InternalInstrumented<SocketStats> getListenSocketStats();
 }

core/src/main/java/io/grpc/internal/ServerImpl.java

@@ -38,6 +38,7 @@ import io.grpc.DecompressorRegistry;
 import io.grpc.HandlerRegistry;
 import io.grpc.InternalChannelz;
 import io.grpc.InternalChannelz.ServerStats;
+import io.grpc.InternalChannelz.SocketStats;
 import io.grpc.InternalInstrumented;
 import io.grpc.InternalLogId;
 import io.grpc.InternalServerInterceptors;
@@ -51,6 +52,8 @@ import io.grpc.ServerTransportFilter;
 import io.grpc.Status;
 import java.io.IOException;
 import java.io.InputStream;
+import java.net.InetSocketAddress;
+import java.net.SocketAddress;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
@@ -136,9 +139,8 @@ public final class ServerImpl extends io.grpc.Server implements InternalInstrume
     Preconditions.checkNotNull(transportServers, "transportServers");
     Preconditions.checkArgument(!transportServers.isEmpty(), "no servers provided");
     this.transportServers = new ArrayList<>(transportServers);
-    // TODO(notcarl): concatenate all listening ports in the Log Id.
     this.logId =
-        InternalLogId.allocate("Server", String.valueOf(transportServers.get(0).getPort()));
+        InternalLogId.allocate("Server", String.valueOf(getListenSocketsIgnoringLifecycle()));
     // Fork from the passed in context so that it does not propagate cancellation, it only
     // inherits values.
     this.rootContext = Preconditions.checkNotNull(rootContext, "rootContext").fork();
@@ -181,21 +183,41 @@ public final class ServerImpl extends io.grpc.Server implements InternalInstrume
     }
   }
 
+
   @Override
   public int getPort() {
     synchronized (lock) {
       checkState(started, "Not started");
       checkState(!terminated, "Already terminated");
       for (InternalServer ts : transportServers) {
-        int port = ts.getPort();
+        SocketAddress addr = ts.getListenSocketAddress();
-        if (port != -1) {
+        if (addr instanceof InetSocketAddress) {
-          return port;
+          return ((InetSocketAddress) addr).getPort();
         }
       }
       return -1;
     }
   }
 
+  @Override
+  public List<SocketAddress> getListenSockets() {
+    synchronized (lock) {
+      checkState(started, "Not started");
+      checkState(!terminated, "Already terminated");
+      return getListenSocketsIgnoringLifecycle();
+    }
+  }
+
+  private List<SocketAddress> getListenSocketsIgnoringLifecycle() {
+    synchronized (lock) {
+      List<SocketAddress> addrs = new ArrayList<>(transportServers.size());
+      for (InternalServer ts : transportServers) {
+        addrs.add(ts.getListenSocketAddress());
+      }
+      return Collections.unmodifiableList(addrs);
+    }
+  }
+
   @Override
   public List<ServerServiceDefinition> getServices() {
     List<ServerServiceDefinition> fallbackServices = fallbackRegistry.getServices();
@@ -602,7 +624,11 @@ public final class ServerImpl extends io.grpc.Server implements InternalInstrume
   public ListenableFuture<ServerStats> getStats() {
     ServerStats.Builder builder = new ServerStats.Builder();
     for (InternalServer ts : transportServers) {
-      builder.addListenSockets(ts.getListenSockets());
+      // TODO(carl-mastrangelo): remove the list and just add directly.
+      InternalInstrumented<SocketStats> stats = ts.getListenSocketStats();
+      if (stats != null ) {
+        builder.addListenSockets(Collections.singletonList(stats));
+      }
     }
     serverCallTracer.updateBuilder(builder);
     SettableFuture<ServerStats> ret = SettableFuture.create();

core/src/test/java/io/grpc/inprocess/InProcessServerTest.java

@@ -38,7 +38,7 @@ public class InProcessServerTest {
     InProcessServer s =
         new InProcessServer(builder, Collections.<ServerStreamTracer.Factory>emptyList());
 
-    Truth.assertThat(s.getPort()).isEqualTo(-1);
+    Truth.assertThat(s.getListenSocketAddress()).isEqualTo(new InProcessSocketAddress("name"));
   }
 
   @Test

core/src/test/java/io/grpc/internal/ServerImplTest.java

@@ -83,6 +83,7 @@ import java.io.ByteArrayInputStream;
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
+import java.net.InetSocketAddress;
 import java.net.SocketAddress;
 import java.util.Arrays;
 import java.util.Collections;
@@ -1070,15 +1071,16 @@ public class ServerImplTest {
 
   @Test
   public void getPort() throws Exception {
+    final InetSocketAddress addr = new InetSocketAddress(65535);
     transportServer = new SimpleServer() {
       @Override
-      public int getPort() {
+      public SocketAddress getListenSocketAddress() {
-        return 65535;
+        return addr;
       }
     };
     createAndStartServer();
 
-    assertThat(server.getPort()).isEqualTo(65535);
+    assertThat(server.getPort()).isEqualTo(addr.getPort());
   }
 
   @Test
@@ -1397,13 +1399,13 @@ public class ServerImplTest {
     }
 
     @Override
-    public int getPort() {
+    public SocketAddress getListenSocketAddress() {
-      return -1;
+      return new InetSocketAddress(12345);
     }
 
     @Override
-    public List<InternalInstrumented<SocketStats>> getListenSockets() {
+    public InternalInstrumented<SocketStats> getListenSocketStats() {
-      return Collections.emptyList();
+      return null;
     }
 
     @Override

interop-testing/src/main/java/io/grpc/testing/integration/AbstractInteropTest.java

@@ -246,8 +246,8 @@ public abstract class AbstractInteropTest {
   }
 
   @VisibleForTesting
-  final int getPort() {
+  final SocketAddress getListenAddress() {
-    return server.getPort();
+    return server.getListenSockets().iterator().next();
   }
 
   protected ManagedChannel channel;

interop-testing/src/test/java/io/grpc/testing/integration/AutoWindowSizingOnTest.java

@@ -43,7 +43,7 @@ public class AutoWindowSizingOnTest extends AbstractInteropTest {
 
   @Override
   protected ManagedChannel createChannel() {
-    NettyChannelBuilder builder = NettyChannelBuilder.forAddress("localhost", getPort())
+    NettyChannelBuilder builder = NettyChannelBuilder.forAddress(getListenAddress())
         .negotiationType(NegotiationType.PLAINTEXT)
         .maxInboundMessageSize(AbstractInteropTest.MAX_MESSAGE_SIZE);
     io.grpc.internal.TestingAccessor.setStatsImplementation(

interop-testing/src/test/java/io/grpc/testing/integration/Http2NettyTest.java

@@ -62,7 +62,7 @@ public class Http2NettyTest extends AbstractInteropTest {
   protected ManagedChannel createChannel() {
     try {
       NettyChannelBuilder builder = NettyChannelBuilder
-          .forAddress(TestUtils.testServerAddress(getPort()))
+          .forAddress(TestUtils.testServerAddress((InetSocketAddress) getListenAddress()))
           .flowControlWindow(65 * 1024)
           .maxInboundMessageSize(AbstractInteropTest.MAX_MESSAGE_SIZE)
           .sslContext(GrpcSslContexts
@@ -80,18 +80,18 @@ public class Http2NettyTest extends AbstractInteropTest {
   }
 
   @Test
-  public void remoteAddr() throws Exception {
+  public void remoteAddr() {
     InetSocketAddress isa = (InetSocketAddress) obtainRemoteClientAddr();
     assertEquals(InetAddress.getLoopbackAddress(), isa.getAddress());
     // It should not be the same as the server
-    assertNotEquals(getPort(), isa.getPort());
+    assertNotEquals(((InetSocketAddress) getListenAddress()).getPort(), isa.getPort());
   }
 
   @Test
   public void localAddr() throws Exception {
     InetSocketAddress isa = (InetSocketAddress) obtainLocalClientAddr();
     assertEquals(InetAddress.getLoopbackAddress(), isa.getAddress());
-    assertEquals(getPort(), isa.getPort());
+    assertEquals(((InetSocketAddress) getListenAddress()).getPort(), isa.getPort());
   }
 
   @Test

interop-testing/src/test/java/io/grpc/testing/integration/Http2OkHttpTest.java

@@ -39,6 +39,7 @@ import io.netty.handler.ssl.SslContextBuilder;
 import io.netty.handler.ssl.SslProvider;
 import io.netty.handler.ssl.SupportedCipherSuiteFilter;
 import java.io.IOException;
+import java.net.InetSocketAddress;
 import javax.net.ssl.HostnameVerifier;
 import javax.net.ssl.SSLPeerUnverifiedException;
 import javax.net.ssl.SSLSession;
@@ -91,13 +92,14 @@ public class Http2OkHttpTest extends AbstractInteropTest {
   }
 
   private OkHttpChannelBuilder createChannelBuilder() {
-    OkHttpChannelBuilder builder = OkHttpChannelBuilder.forAddress("localhost", getPort())
+    int port = ((InetSocketAddress) getListenAddress()).getPort();
+    OkHttpChannelBuilder builder = OkHttpChannelBuilder.forAddress("localhost", port)
         .maxInboundMessageSize(AbstractInteropTest.MAX_MESSAGE_SIZE)
         .connectionSpec(new ConnectionSpec.Builder(ConnectionSpec.MODERN_TLS)
             .cipherSuites(TestUtils.preferredTestCiphers().toArray(new String[0]))
             .build())
         .overrideAuthority(GrpcUtil.authorityFromHostAndPort(
-            TestUtils.TEST_SERVER_HOST, getPort()));
+            TestUtils.TEST_SERVER_HOST, port));
     io.grpc.internal.TestingAccessor.setStatsImplementation(
         builder, createClientCensusStatsModule());
     try {
@@ -135,9 +137,10 @@ public class Http2OkHttpTest extends AbstractInteropTest {
 
   @Test
   public void wrongHostNameFailHostnameVerification() throws Exception {
+    int port = ((InetSocketAddress) getListenAddress()).getPort();
     ManagedChannel channel = createChannelBuilder()
         .overrideAuthority(GrpcUtil.authorityFromHostAndPort(
-            BAD_HOSTNAME, getPort()))
+            BAD_HOSTNAME, port))
         .build();
     TestServiceGrpc.TestServiceBlockingStub blockingStub =
         TestServiceGrpc.newBlockingStub(channel);
@@ -157,9 +160,10 @@ public class Http2OkHttpTest extends AbstractInteropTest {
 
   @Test
   public void hostnameVerifierWithBadHostname() throws Exception {
+    int port = ((InetSocketAddress) getListenAddress()).getPort();
     ManagedChannel channel = createChannelBuilder()
         .overrideAuthority(GrpcUtil.authorityFromHostAndPort(
-            BAD_HOSTNAME, getPort()))
+            BAD_HOSTNAME, port))
         .hostnameVerifier(new HostnameVerifier() {
           @Override
           public boolean verify(String hostname, SSLSession session) {
@@ -177,9 +181,10 @@ public class Http2OkHttpTest extends AbstractInteropTest {
 
   @Test
   public void hostnameVerifierWithCorrectHostname() throws Exception {
+    int port = ((InetSocketAddress) getListenAddress()).getPort();
     ManagedChannel channel = createChannelBuilder()
         .overrideAuthority(GrpcUtil.authorityFromHostAndPort(
-            TestUtils.TEST_SERVER_HOST, getPort()))
+            TestUtils.TEST_SERVER_HOST, port))
         .hostnameVerifier(new HostnameVerifier() {
           @Override
           public boolean verify(String hostname, SSLSession session) {

interop-testing/src/test/java/io/grpc/testing/integration/TransportCompressionTest.java

@@ -123,7 +123,7 @@ public class TransportCompressionTest extends AbstractInteropTest {
 
   @Override
   protected ManagedChannel createChannel() {
-    NettyChannelBuilder builder = NettyChannelBuilder.forAddress("localhost", getPort())
+    NettyChannelBuilder builder = NettyChannelBuilder.forAddress(getListenAddress())
         .maxInboundMessageSize(AbstractInteropTest.MAX_MESSAGE_SIZE)
         .decompressorRegistry(decompressors)
         .compressorRegistry(compressors)

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

@@ -23,7 +23,6 @@ import static io.netty.channel.ChannelOption.SO_KEEPALIVE;
 
 import com.google.common.base.MoreObjects;
 import com.google.common.base.Preconditions;
-import com.google.common.collect.ImmutableList;
 import com.google.common.util.concurrent.ListenableFuture;
 import com.google.common.util.concurrent.SettableFuture;
 import io.grpc.InternalChannelz;
@@ -52,11 +51,11 @@ import io.netty.util.ReferenceCounted;
 import io.netty.util.concurrent.Future;
 import io.netty.util.concurrent.GenericFutureListener;
 import java.io.IOException;
-import java.net.InetSocketAddress;
 import java.net.SocketAddress;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.concurrent.atomic.AtomicReference;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 import javax.annotation.Nullable;
@@ -94,9 +93,8 @@ class NettyServer implements InternalServer, InternalWithLogId {
   private final TransportTracer.Factory transportTracerFactory;
   private final InternalChannelz channelz;
   // Only modified in event loop but safe to read any time. Set at startup and unset at shutdown.
-  // In the future we may have >1 listen socket.
+  private final AtomicReference<InternalInstrumented<SocketStats>> listenSocketStats =
-  private volatile ImmutableList<InternalInstrumented<SocketStats>> listenSockets
+      new AtomicReference<>();
-      = ImmutableList.of();
 
   NettyServer(
       SocketAddress address, Class<? extends ServerChannel> channelType,
@@ -139,20 +137,17 @@ class NettyServer implements InternalServer, InternalWithLogId {
   }
 
   @Override
-  public int getPort() {
+  public SocketAddress getListenSocketAddress() {
     if (channel == null) {
-      return -1;
+      // server is not listening/bound yet, just return the original port.
+      return address;
     }
-    SocketAddress localAddr = channel.localAddress();
+    return channel.localAddress();
-    if (!(localAddr instanceof InetSocketAddress)) {
-      return -1;
-    }
-    return ((InetSocketAddress) localAddr).getPort();
   }
 
   @Override
-  public List<InternalInstrumented<SocketStats>> getListenSockets() {
+  public InternalInstrumented<SocketStats> getListenSocketStats() {
-    return listenSockets;
+    return listenSocketStats.get();
   }
 
   @Override
@@ -260,7 +255,7 @@ class NettyServer implements InternalServer, InternalWithLogId {
       @Override
       public void run() {
         InternalInstrumented<SocketStats> listenSocket = new ListenSocket(channel);
-        listenSockets = ImmutableList.of(listenSocket);
+        listenSocketStats.set(listenSocket);
         channelz.addListenSocket(listenSocket);
       }
     });
@@ -283,10 +278,10 @@ class NettyServer implements InternalServer, InternalWithLogId {
         if (!future.isSuccess()) {
           log.log(Level.WARNING, "Error shutting down server", future.cause());
         }
-        for (InternalInstrumented<SocketStats> listenSocket : listenSockets) {
+        InternalInstrumented<SocketStats> stats = listenSocketStats.getAndSet(null);
-          channelz.removeListenSocket(listenSocket);
+        if (stats != null) {
+          channelz.removeListenSocket(stats);
         }
-        listenSockets = null;
         synchronized (NettyServer.this) {
           listener.serverShutdown();
         }

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

@@ -17,12 +17,12 @@
 package io.grpc.netty;
 
 import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
 import static io.grpc.internal.GrpcUtil.DEFAULT_MAX_MESSAGE_SIZE;
 import static io.grpc.internal.GrpcUtil.DEFAULT_SERVER_KEEPALIVE_TIMEOUT_NANOS;
 import static io.grpc.internal.GrpcUtil.DEFAULT_SERVER_KEEPALIVE_TIME_NANOS;
 import static io.grpc.internal.GrpcUtil.SERVER_KEEPALIVE_TIME_NANOS_DISABLED;
 
-import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Preconditions;
 import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import io.grpc.ExperimentalApi;
@@ -121,11 +121,13 @@ public final class NettyServerBuilder extends AbstractServerImplBuilder<NettySer
     this.listenAddresses.add(address);
   }
 
-
+  /**
-  // TODO(notcarl): expose this API at a higher level.
+   * Adds an additional address for this server to listen on.  Callers must ensure that all socket
-  @VisibleForTesting
+   * addresses are compatible with the Netty channel type, and that they don't conflict with each
-  NettyServerBuilder addPort(int port) {
+   * other.
-    this.listenAddresses.add(new InetSocketAddress(port));
+   */
+  public NettyServerBuilder addListenAddress(SocketAddress listenAddress) {
+    this.listenAddresses.add(checkNotNull(listenAddress, "listenAddress"));
     return this;
   }
 

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

@@ -150,7 +150,7 @@ public class NettyClientTransportTest {
 
   @Test
   public void testToString() throws Exception {
-    address = TestUtils.testServerAddress(12345);
+    address = TestUtils.testServerAddress(new InetSocketAddress(12345));
     authority = GrpcUtil.authorityFromHostAndPort(address.getHostString(), address.getPort());
     String s = newTransport(newNegotiator()).toString();
     transports.clear();
@@ -420,7 +420,7 @@ public class NettyClientTransportTest {
 
   @Test
   public void failingToConstructChannelShouldFailGracefully() throws Exception {
-    address = TestUtils.testServerAddress(12345);
+    address = TestUtils.testServerAddress(new InetSocketAddress(12345));
     authority = GrpcUtil.authorityFromHostAndPort(address.getHostString(), address.getPort());
     NettyClientTransport transport = new NettyClientTransport(
         address, new ReflectiveChannelFactory<>(CantConstructChannel.class),
@@ -539,7 +539,7 @@ public class NettyClientTransportTest {
 
   @Test
   public void getAttributes_negotiatorHandler() throws Exception {
-    address = TestUtils.testServerAddress(12345);
+    address = TestUtils.testServerAddress(new InetSocketAddress(12345));
     authority = GrpcUtil.authorityFromHostAndPort(address.getHostString(), address.getPort());
 
     NettyClientTransport transport = newTransport(new NoopProtocolNegotiator());
@@ -550,7 +550,7 @@ public class NettyClientTransportTest {
 
   @Test
   public void getEagAttributes_negotiatorHandler() throws Exception {
-    address = TestUtils.testServerAddress(12345);
+    address = TestUtils.testServerAddress(new InetSocketAddress(12345));
     authority = GrpcUtil.authorityFromHostAndPort(address.getHostString(), address.getPort());
 
     NoopProtocolNegotiator npn = new NoopProtocolNegotiator();
@@ -654,7 +654,7 @@ public class NettyClientTransportTest {
 
   private void startServer(int maxStreamsPerConnection, int maxHeaderListSize) throws IOException {
     server = new NettyServer(
-        TestUtils.testServerAddress(0),
+        TestUtils.testServerAddress(new InetSocketAddress(0)),
         NioServerSocketChannel.class,
         new HashMap<ChannelOption<?>, Object>(),
         group, group, negotiator,
@@ -667,7 +667,7 @@ public class NettyClientTransportTest {
         MAX_CONNECTION_AGE_NANOS_DISABLED, MAX_CONNECTION_AGE_GRACE_NANOS_INFINITE, true, 0,
         channelz);
     server.start(serverListener);
-    address = TestUtils.testServerAddress(server.getPort());
+    address = TestUtils.testServerAddress((InetSocketAddress) server.getListenSocketAddress());
     authority = GrpcUtil.authorityFromHostAndPort(address.getHostString(), address.getPort());
   }
 

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

@@ -23,6 +23,7 @@ import com.google.common.collect.ImmutableList;
 import com.google.common.truth.Truth;
 import io.grpc.ServerStreamTracer.Factory;
 import io.netty.handler.ssl.SslContext;
+import java.net.InetSocketAddress;
 import java.util.List;
 import java.util.concurrent.TimeUnit;
 import org.junit.Rule;
@@ -43,7 +44,7 @@ public class NettyServerBuilderTest {
 
   @Test
   public void createMultipleServers() {
-    builder.addPort(8081);
+    builder.addListenAddress(new InetSocketAddress(8081));
     List<NettyServer> servers = builder.buildTransportServers(ImmutableList.<Factory>of());
 
     Truth.assertThat(servers).hasSize(2);

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

@@ -16,7 +16,6 @@
 
 package io.grpc.netty;
 
-import static com.google.common.collect.Iterables.getOnlyElement;
 import static com.google.common.truth.Truth.assertThat;
 import static io.grpc.InternalChannelz.id;
 import static org.junit.Assert.assertEquals;
@@ -86,7 +85,7 @@ public class NettyServerTest {
     });
 
     // Check that we got an actual port.
-    assertThat(ns.getPort()).isGreaterThan(0);
+    assertThat(((InetSocketAddress) ns.getListenSocketAddress()).getPort()).isGreaterThan(0);
 
     // Cleanup
     ns.shutdown();
@@ -114,7 +113,7 @@ public class NettyServerTest {
         true, 0, // ignore
         channelz);
 
-    assertThat(ns.getPort()).isEqualTo(-1);
+    assertThat(ns.getListenSocketAddress()).isEqualTo(addr);
   }
 
   @Test(timeout = 60000)
@@ -170,7 +169,7 @@ public class NettyServerTest {
     });
 
     Socket socket = new Socket();
-    socket.connect(new InetSocketAddress("localhost", ns.getPort()), /* timeout= */ 8000);
+    socket.connect(ns.getListenSocketAddress(), /* timeout= */ 8000);
     countDownLatch.await();
     socket.close();
 
@@ -213,14 +212,14 @@ public class NettyServerTest {
         shutdownCompleted.set(null);
       }
     });
-    assertThat(ns.getPort()).isGreaterThan(0);
+    assertThat(((InetSocketAddress) ns.getListenSocketAddress()).getPort()).isGreaterThan(0);
 
-    InternalInstrumented<SocketStats> listenSocket = getOnlyElement(ns.getListenSockets());
+    InternalInstrumented<SocketStats> listenSocket = ns.getListenSocketStats();
     assertSame(listenSocket, channelz.getSocket(id(listenSocket)));
 
     // very basic sanity check of the contents
     SocketStats socketStats = listenSocket.getStats().get();
-    assertEquals(ns.getPort(), ((InetSocketAddress) socketStats.local).getPort());
+    assertEquals(ns.getListenSocketAddress(), socketStats.local);
     assertNull(socketStats.remote);
 
     // TODO(zpencer): uncomment when sock options are exposed

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

@@ -58,7 +58,7 @@ public class NettyTransportTest extends AbstractTransportTest {
   protected List<? extends InternalServer> newServer(
       List<ServerStreamTracer.Factory> streamTracerFactories) {
     return NettyServerBuilder
-        .forPort(0)
+        .forAddress(new InetSocketAddress("localhost", 0))
         .flowControlWindow(65 * 1024)
         .setTransportTracerFactory(fakeClockTransportTracer)
         .buildTransportServers(streamTracerFactories);
@@ -68,7 +68,7 @@ public class NettyTransportTest extends AbstractTransportTest {
   protected List<? extends InternalServer> newServer(
       int port, List<ServerStreamTracer.Factory> streamTracerFactories) {
     return NettyServerBuilder
-        .forPort(port)
+        .forAddress(new InetSocketAddress("localhost", port))
         .flowControlWindow(65 * 1024)
         .setTransportTracerFactory(fakeClockTransportTracer)
         .buildTransportServers(streamTracerFactories);
@@ -76,7 +76,7 @@ public class NettyTransportTest extends AbstractTransportTest {
 
   @Override
   protected String testAuthority(InternalServer server) {
-    return "localhost:" + server.getPort();
+    return "localhost:" + server.getListenSocketAddress();
   }
 
   @Override
@@ -91,9 +91,8 @@ public class NettyTransportTest extends AbstractTransportTest {
 
   @Override
   protected ManagedClientTransport newClientTransport(InternalServer server) {
-    int port = server.getPort();
     return clientFactory.newClientTransport(
-        new InetSocketAddress("localhost", port),
+        server.getListenSocketAddress(),
         new ClientTransportFactory.ClientTransportOptions()
           .setAuthority(testAuthority(server)));
   }

okhttp/src/test/java/io/grpc/okhttp/OkHttpTransportTest.java

@@ -66,7 +66,7 @@ public class OkHttpTransportTest extends AbstractTransportTest {
       int port, List<ServerStreamTracer.Factory> streamTracerFactories) {
     return AccessProtectedHack.serverBuilderBuildTransportServer(
         NettyServerBuilder
-            .forPort(port)
+            .forAddress(new InetSocketAddress(port))
             .flowControlWindow(65 * 1024),
         streamTracerFactories,
         fakeClockTransportTracer);
@@ -74,12 +74,12 @@ public class OkHttpTransportTest extends AbstractTransportTest {
 
   @Override
   protected String testAuthority(InternalServer server) {
-    return "thebestauthority:" + server.getPort();
+    return "thebestauthority:" + server.getListenSocketAddress();
   }
 
   @Override
   protected ManagedClientTransport newClientTransport(InternalServer server) {
-    int port = server.getPort();
+    int port = ((InetSocketAddress) server.getListenSocketAddress()).getPort();
     return clientFactory.newClientTransport(
         new InetSocketAddress("localhost", port),
         new ClientTransportFactory.ClientTransportOptions()

testing/src/main/java/io/grpc/internal/testing/AbstractTransportTest.java

@@ -74,6 +74,7 @@ import io.grpc.internal.TransportTracer;
 import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.io.InputStream;
+import java.net.InetSocketAddress;
 import java.net.SocketAddress;
 import java.util.Arrays;
 import java.util.List;
@@ -364,7 +365,11 @@ public abstract class AbstractTransportTest {
   public void serverAlreadyListening() throws Exception {
     client = null;
     server.start(serverListener);
-    int port = server.getPort();
+    int port = -1;
+    SocketAddress addr = server.getListenSocketAddress();
+    if (addr instanceof InetSocketAddress) {
+      port = ((InetSocketAddress) addr).getPort();
+    }
     InternalServer server2 =
         Iterables.getOnlyElement(newServer(port, Arrays.asList(serverStreamTracerFactory)));
     thrown.expect(IOException.class);
@@ -374,7 +379,11 @@ public abstract class AbstractTransportTest {
   @Test
   public void openStreamPreventsTermination() throws Exception {
     server.start(serverListener);
-    int port = server.getPort();
+    int port = -1;
+    SocketAddress addr = server.getListenSocketAddress();
+    if (addr instanceof InetSocketAddress) {
+      port = ((InetSocketAddress) addr).getPort();
+    }
     client = newClientTransport(server);
     startTransport(client, mockClientTransportListener);
     MockServerTransportListener serverTransportListener
@@ -1800,15 +1809,19 @@ public abstract class AbstractTransportTest {
     SocketAddress clientAddress = serverStream.getAttributes().get(Grpc.TRANSPORT_ATTR_REMOTE_ADDR);
 
     SocketStats clientSocketStats = client.getStats().get();
-    assertEquals(clientAddress, clientSocketStats.local);
+    assertEquals(
-    assertEquals(serverAddress, clientSocketStats.remote);
+        "clientLocal " + clientStream.getAttributes(), clientAddress, clientSocketStats.local);
+    assertEquals(
+        "clientRemote " + clientStream.getAttributes(), serverAddress, clientSocketStats.remote);
     // very basic sanity check that socket options are populated
     assertNotNull(clientSocketStats.socketOptions.lingerSeconds);
     assertTrue(clientSocketStats.socketOptions.others.containsKey("SO_SNDBUF"));
 
     SocketStats serverSocketStats = serverTransportListener.transport.getStats().get();
-    assertEquals(serverAddress, serverSocketStats.local);
+    assertEquals(
-    assertEquals(clientAddress, serverSocketStats.remote);
+        "serverLocal " + serverStream.getAttributes(), serverAddress, serverSocketStats.local);
+    assertEquals(
+        "serverRemote " + serverStream.getAttributes(), clientAddress, serverSocketStats.remote);
     // very basic sanity check that socket options are populated
     assertNotNull(serverSocketStats.socketOptions.lingerSeconds);
     assertTrue(serverSocketStats.socketOptions.others.containsKey("SO_SNDBUF"));

testing/src/main/java/io/grpc/internal/testing/TestUtils.java

@@ -67,11 +67,11 @@ public class TestUtils {
    * Creates a new {@link InetSocketAddress} on localhost that overrides the host with
    * {@link #TEST_SERVER_HOST}.
    */
-  public static InetSocketAddress testServerAddress(int port) {
+  public static InetSocketAddress testServerAddress(InetSocketAddress originalSockAddr) {
     try {
       InetAddress inetAddress = InetAddress.getByName("localhost");
       inetAddress = InetAddress.getByAddress(TEST_SERVER_HOST, inetAddress.getAddress());
-      return new InetSocketAddress(inetAddress, port);
+      return new InetSocketAddress(inetAddress, originalSockAddr.getPort());
     } catch (UnknownHostException e) {
       throw new RuntimeException(e);
     }