xds: implement XdsServerCredentials (#7636)

Co-authored-by: Eric Anderson <ejona@google.com>

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

@@ -49,9 +49,9 @@ public static ServerCredentials create(InternalProtocolNegotiator.ServerFactory
    * @throws IllegalArgumentException if unable to convert
    */
   public static InternalProtocolNegotiator.ServerFactory toNegotiator(
-      ServerCredentials channelCredentials) {
+      ServerCredentials serverCredentials) {
     final ProtocolNegotiators.FromServerCredentialsResult result =
-        ProtocolNegotiators.from(channelCredentials);
+        ProtocolNegotiators.from(serverCredentials);
     if (result.error != null) {
       throw new IllegalArgumentException(result.error);
     }

xds/src/main/java/io/grpc/xds/XdsServerBuilder.java

@@ -17,12 +17,14 @@
 package io.grpc.xds;
 
 import com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.Preconditions;
 import io.grpc.Attributes;
 import io.grpc.ExperimentalApi;
 import io.grpc.ForwardingServerBuilder;
 import io.grpc.Internal;
 import io.grpc.Server;
 import io.grpc.ServerBuilder;
+import io.grpc.ServerCredentials;
 import io.grpc.Status;
 import io.grpc.netty.InternalNettyServerBuilder;
 import io.grpc.netty.InternalProtocolNegotiator.ProtocolNegotiator;
@@ -46,12 +48,14 @@ public final class XdsServerBuilder extends ForwardingServerBuilder<XdsServerBui
 
   private final NettyServerBuilder delegate;
   private final int port;
+  private final boolean freezeNegotiator;
   private ProtocolNegotiator fallbackProtocolNegotiator;
   private ErrorNotifier errorNotifier;
 
-  private XdsServerBuilder(NettyServerBuilder nettyDelegate, int port) {
+  private XdsServerBuilder(NettyServerBuilder nettyDelegate, int port, boolean freezeNegotiator) {
     this.delegate = nettyDelegate;
     this.port = port;
+    this.freezeNegotiator = freezeNegotiator;
   }
 
   @Override
@@ -66,6 +70,7 @@ protected ServerBuilder<?> delegate() {
    */
   @ExperimentalApi("https://github.com/grpc/grpc-java/issues/7514")
   public XdsServerBuilder useXdsSecurityWithPlaintextFallback() {
+    Preconditions.checkState(!freezeNegotiator, "Method unavailable when using ServerCredentials");
     this.fallbackProtocolNegotiator = InternalProtocolNegotiators.serverPlaintext();
     return this;
   }
@@ -80,6 +85,7 @@ public XdsServerBuilder useXdsSecurityWithPlaintextFallback() {
   @ExperimentalApi("https://github.com/grpc/grpc-java/issues/7514")
   public XdsServerBuilder useXdsSecurityWithTransportSecurityFallback(
       File certChain, File privateKey) throws SSLException {
+    Preconditions.checkState(!freezeNegotiator, "Method unavailable when using ServerCredentials");
     SslContext sslContext = SslContextBuilder.forServer(certChain, privateKey).build();
     this.fallbackProtocolNegotiator = InternalProtocolNegotiators.serverTls(sslContext);
     return this;
@@ -95,6 +101,7 @@ public XdsServerBuilder useXdsSecurityWithTransportSecurityFallback(
   @ExperimentalApi("https://github.com/grpc/grpc-java/issues/7514")
   public XdsServerBuilder useXdsSecurityWithTransportSecurityFallback(
       InputStream certChain, InputStream privateKey) throws SSLException {
+    Preconditions.checkState(!freezeNegotiator, "Method unavailable when using ServerCredentials");
     SslContext sslContext = SslContextBuilder.forServer(certChain, privateKey).build();
     this.fallbackProtocolNegotiator = InternalProtocolNegotiators.serverTls(sslContext);
     return this;
@@ -103,6 +110,7 @@ public XdsServerBuilder useXdsSecurityWithTransportSecurityFallback(
   /** Set the fallback protocolNegotiator. Pass null to unset a previously set value. */
   public XdsServerBuilder fallbackProtocolNegotiator(
       ProtocolNegotiator fallbackProtocolNegotiator) {
+    Preconditions.checkState(!freezeNegotiator, "Method unavailable when using ServerCredentials");
     this.fallbackProtocolNegotiator = fallbackProtocolNegotiator;
     return this;
   }
@@ -116,7 +124,13 @@ public XdsServerBuilder errorNotifier(ErrorNotifier errorNotifier) {
   /** Creates a gRPC server builder for the given port. */
   public static XdsServerBuilder forPort(int port) {
     NettyServerBuilder nettyDelegate = NettyServerBuilder.forAddress(new InetSocketAddress(port));
-    return new XdsServerBuilder(nettyDelegate, port);
+    return new XdsServerBuilder(nettyDelegate, port, /* freezeNegotiator= */ false);
+  }
+
+  /** Creates a gRPC server builder for the given port. */
+  public static XdsServerBuilder forPort(int port, ServerCredentials serverCredentials) {
+    NettyServerBuilder nettyDelegate = NettyServerBuilder.forPort(port, serverCredentials);
+    return new XdsServerBuilder(nettyDelegate, port, /* freezeNegotiator= */ true);
   }
 
   @Override

xds/src/main/java/io/grpc/xds/XdsServerCredentials.java

@@ -0,0 +1,45 @@
+/*
+ * Copyright 2020 The gRPC 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
+ *
+ *     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 io.grpc.xds;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import io.grpc.ExperimentalApi;
+import io.grpc.ServerCredentials;
+import io.grpc.netty.InternalNettyServerCredentials;
+import io.grpc.netty.InternalProtocolNegotiator;
+import io.grpc.xds.internal.sds.SdsProtocolNegotiators;
+
+@ExperimentalApi("https://github.com/grpc/grpc-java/issues/7621")
+public class XdsServerCredentials {
+  private XdsServerCredentials() {} // prevent instantiation
+
+  /**
+   * Creates credentials to be configured by xDS, falling back to other credentials if no
+   * TLS configuration is provided by xDS.
+   *
+   * @param fallback Credentials to fall back to.
+   *
+   * @throws IllegalArgumentException if fallback is unable to be used
+   */
+  public static ServerCredentials create(ServerCredentials fallback) {
+    InternalProtocolNegotiator.ServerFactory fallbackNegotiator =
+        InternalNettyServerCredentials.toNegotiator(checkNotNull(fallback, "fallback"));
+    return InternalNettyServerCredentials.create(
+        SdsProtocolNegotiators.serverProtocolNegotiatorFactory(fallbackNegotiator));
+  }
+}

xds/src/main/java/io/grpc/xds/internal/sds/SdsProtocolNegotiators.java

@@ -21,6 +21,7 @@
 import com.google.common.annotations.VisibleForTesting;
 import io.grpc.Attributes;
 import io.grpc.internal.GrpcUtil;
+import io.grpc.internal.ObjectPool;
 import io.grpc.netty.GrpcHttp2ConnectionHandler;
 import io.grpc.netty.InternalNettyChannelBuilder;
 import io.grpc.netty.InternalNettyChannelBuilder.ProtocolNegotiatorFactory;
@@ -42,6 +43,7 @@
 import java.security.cert.CertStoreException;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.concurrent.Executor;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 import javax.annotation.Nullable;
@@ -84,6 +86,11 @@ public static InternalProtocolNegotiator.ClientFactory clientProtocolNegotiatorF
     return new ClientFactory(fallbackNegotiator);
   }
 
+  public static InternalProtocolNegotiator.ServerFactory serverProtocolNegotiatorFactory(
+      @Nullable InternalProtocolNegotiator.ServerFactory fallbackNegotiator) {
+    return new ServerFactory(fallbackNegotiator);
+  }
+
   /**
    * Creates an SDS based {@link ProtocolNegotiator} for a {@link io.grpc.netty.NettyServerBuilder}.
    * If xDS returns no DownstreamTlsContext, it will fall back to plaintext.
@@ -95,6 +102,21 @@ public static ServerSdsProtocolNegotiator serverProtocolNegotiator(
     return new ServerSdsProtocolNegotiator(fallbackProtocolNegotiator);
   }
 
+  private static final class ServerFactory implements InternalProtocolNegotiator.ServerFactory {
+
+    private final InternalProtocolNegotiator.ServerFactory fallbackProtocolNegotiator;
+
+    private ServerFactory(InternalProtocolNegotiator.ServerFactory fallbackNegotiator) {
+      this.fallbackProtocolNegotiator = fallbackNegotiator;
+    }
+
+    @Override
+    public ProtocolNegotiator newNegotiator(ObjectPool<? extends Executor> offloadExecutorPool) {
+      return new ServerSdsProtocolNegotiator(
+          fallbackProtocolNegotiator.newNegotiator(offloadExecutorPool));
+    }
+  }
+
   private static final class ClientFactory implements InternalProtocolNegotiator.ClientFactory {
 
     private final InternalProtocolNegotiator.ClientFactory fallbackProtocolNegotiator;

xds/src/test/java/io/grpc/xds/XdsSdsClientServerTest.java

@@ -35,13 +35,14 @@
 import io.grpc.EquivalentAddressGroup;
 import io.grpc.Grpc;
 import io.grpc.InsecureChannelCredentials;
+import io.grpc.InsecureServerCredentials;
 import io.grpc.ManagedChannelBuilder;
 import io.grpc.NameResolver;
 import io.grpc.NameResolverProvider;
 import io.grpc.NameResolverRegistry;
+import io.grpc.ServerCredentials;
 import io.grpc.Status;
 import io.grpc.StatusRuntimeException;
-import io.grpc.netty.InternalProtocolNegotiator.ProtocolNegotiator;
 import io.grpc.netty.InternalProtocolNegotiators;
 import io.grpc.stub.StreamObserver;
 import io.grpc.testing.GrpcCleanupRule;
@@ -51,7 +52,6 @@
 import io.grpc.xds.EnvoyServerProtoData.DownstreamTlsContext;
 import io.grpc.xds.EnvoyServerProtoData.UpstreamTlsContext;
 import io.grpc.xds.internal.sds.CommonTlsContextTestsUtil;
-import io.grpc.xds.internal.sds.SdsProtocolNegotiators;
 import io.grpc.xds.internal.sds.SslContextProviderSupplier;
 import io.grpc.xds.internal.sds.TlsContextManagerImpl;
 import io.grpc.xds.internal.sds.XdsChannelBuilder;
@@ -129,18 +129,12 @@ public void plaintextClientServer_withDefaultTlsContext() throws IOException, UR
   }
 
   @Test
-  public void nullFallbackProtocolNegotiator_expectException()
-      throws IOException, URISyntaxException {
-    buildServerWithTlsContext(/* downstreamTlsContext= */ null,
-        /* fallbackProtocolNegotiator= */ null);
-
-    SimpleServiceGrpc.SimpleServiceBlockingStub blockingStub =
-        getBlockingStub(/* upstreamTlsContext= */ null, /* overrideAuthority= */ null);
+  public void nullFallbackCredentials_expectException() throws IOException, URISyntaxException {
     try {
-      unaryRpc("buddy", blockingStub);
+      buildServerWithTlsContext(/* downstreamTlsContext= */ null, /* fallbackCredentials= */ null);
       fail("exception expected");
-    } catch (StatusRuntimeException sre) {
-      assertThat(sre.getStatus().getCode()).isEqualTo(Status.UNAVAILABLE.getCode());
+    } catch (NullPointerException npe) {
+      assertThat(npe).hasMessageThat().isEqualTo("fallback");
     }
   }
 
@@ -309,8 +303,8 @@ private XdsClient.ListenerWatcher performMtlsTestAndGetListenerWatcher(
     final XdsClientWrapperForServerSds xdsClientWrapperForServerSds =
         XdsClientWrapperForServerSdsTest.createXdsClientWrapperForServerSds(
             port, /* downstreamTlsContext= */ downstreamTlsContext);
-    buildServerWithFallbackProtocolNegotiator(xdsClientWrapperForServerSds,
-        InternalProtocolNegotiators.serverPlaintext(), downstreamTlsContext);
+    buildServerWithFallbackServerCredentials(
+        xdsClientWrapperForServerSds, InsecureServerCredentials.create(), downstreamTlsContext);
 
     XdsClient.ListenerWatcher listenerWatcher = xdsClientWrapperForServerSds.getListenerWatcher();
 
@@ -323,46 +317,43 @@ private XdsClient.ListenerWatcher performMtlsTestAndGetListenerWatcher(
 
   private void buildServerWithTlsContext(DownstreamTlsContext downstreamTlsContext)
       throws IOException {
-    buildServerWithTlsContext(downstreamTlsContext,
-        InternalProtocolNegotiators.serverPlaintext());
+    buildServerWithTlsContext(downstreamTlsContext, InsecureServerCredentials.create());
   }
 
-  private void buildServerWithTlsContext(DownstreamTlsContext downstreamTlsContext,
-      ProtocolNegotiator fallbackProtocolNegotiator)
+  private void buildServerWithTlsContext(
+      DownstreamTlsContext downstreamTlsContext, ServerCredentials fallbackCredentials)
       throws IOException {
     XdsClient mockXdsClient = mock(XdsClient.class);
     XdsClientWrapperForServerSds xdsClientWrapperForServerSds =
         new XdsClientWrapperForServerSds(port);
     xdsClientWrapperForServerSds.start(mockXdsClient);
-    buildServerWithFallbackProtocolNegotiator(
-        xdsClientWrapperForServerSds, fallbackProtocolNegotiator, downstreamTlsContext);
+    buildServerWithFallbackServerCredentials(
+        xdsClientWrapperForServerSds, fallbackCredentials, downstreamTlsContext);
   }
 
-  private void buildServerWithFallbackProtocolNegotiator(
+  private void buildServerWithFallbackServerCredentials(
       XdsClientWrapperForServerSds xdsClientWrapperForServerSds,
-      ProtocolNegotiator fallbackProtocolNegotiator,
+      ServerCredentials fallbackCredentials,
       DownstreamTlsContext downstreamTlsContext)
       throws IOException {
-    SdsProtocolNegotiators.ServerSdsProtocolNegotiator serverSdsProtocolNegotiator =
-        new SdsProtocolNegotiators.ServerSdsProtocolNegotiator(fallbackProtocolNegotiator);
-    buildServer(
-        port, serverSdsProtocolNegotiator, xdsClientWrapperForServerSds, downstreamTlsContext);
+    ServerCredentials xdsCredentials = XdsServerCredentials.create(fallbackCredentials);
+    buildServer(port, xdsCredentials, xdsClientWrapperForServerSds, downstreamTlsContext);
   }
 
   private void buildServer(
       int port,
-      SdsProtocolNegotiators.ServerSdsProtocolNegotiator serverSdsProtocolNegotiator,
+      ServerCredentials serverCredentials,
       XdsClientWrapperForServerSds xdsClientWrapperForServerSds,
       DownstreamTlsContext downstreamTlsContext)
       throws IOException {
-    XdsServerBuilder builder = XdsServerBuilder.forPort(port).addService(new SimpleServiceImpl());
+    XdsServerBuilder builder = XdsServerBuilder.forPort(port, serverCredentials)
+        .addService(new SimpleServiceImpl());
     XdsServerTestHelper.generateListenerUpdate(
         xdsClientWrapperForServerSds.getListenerWatcher(),
         port,
-            downstreamTlsContext,
+        downstreamTlsContext,
         /* tlsContext2= */null);
-    cleanupRule.register(
-        builder.buildServer(xdsClientWrapperForServerSds, serverSdsProtocolNegotiator)).start();
+    cleanupRule.register(builder.buildServer(xdsClientWrapperForServerSds, null)).start();
   }
 
   static EnvoyServerProtoData.Listener buildListener(