xds: fix xdsClient resource not exist for invalid resource, fix xdsServerWrapper start on resource not exist (1.42.x backport) (#8690)

* xds: remove filter chain uuid name generator (#8663)

Generating a uuid in filterChain breaks the de-duplication detection which causes XdsServer to cycle connections, so removing it.
An empty name is now allowed. The name is currently only used for debug purpose.

* xds: fix xdsClient resource not exist for invalid resource, fix xdsServerWrapper start on resource not exist (#8660)

Fix bugs:
1. Invalid resource at xdsClient, the watcher should have been delivered an error instead of resource not found.
2. If the resource is properly determined to not exist, it shouldn't cause start() to fail. From A36 xDS for Servers:
"XdsServer's start must not fail due to transient xDS issues, like missing xDS configuration from the xDS server."

Author: YifeiZhuang

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

@@ -2077,11 +2077,13 @@ private void handleResourceUpdate(
             }
             retainedResources.add(edsName);
           }
-          continue;
+        } else if (invalidResources.contains(resourceName)) {
+          subscriber.onError(Status.UNAVAILABLE.withDescription(errorDetail));
+        } else {
+          // For State of the World services, notify watchers when their watched resource is missing
+          // from the ADS update.
+          subscriber.onAbsent();
         }
-        // For State of the World services, notify watchers when their watched resource is missing
-        // from the ADS update.
-        subscriber.onAbsent();
       }
     }
     // LDS/CDS responses represents the state of the world, RDS/EDS resources not referenced in

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

@@ -571,10 +571,6 @@ private void handleConfigNotFound(StatusException exception) {
       for (SslContextProviderSupplier s: toRelease) {
         s.close();
       }
-      if (!initialStarted) {
-        initialStarted = true;
-        initialStartFuture.set(exception);
-      }
       if (restartTimer != null) {
         restartTimer.cancel();
       }

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

@@ -1555,12 +1555,16 @@ public void cdsResponseErrorHandling_badUpstreamTlsContext() {
     call.sendResponse(CDS, clusters, VERSION_1, "0000");
 
     // The response NACKed with errors indicating indices of the failed resources.
-    call.verifyRequestNack(CDS, CDS_RESOURCE, "", "0000", NODE, ImmutableList.of(
-        "CDS response Cluster 'cluster.googleapis.com' validation error: "
+    String errorMsg =  "CDS response Cluster 'cluster.googleapis.com' validation error: "
             + "Cluster cluster.googleapis.com: malformed UpstreamTlsContext: "
             + "io.grpc.xds.ClientXdsClient$ResourceInvalidException: "
-            + "ca_certificate_provider_instance is required in upstream-tls-context"));
-    verifyNoInteractions(cdsResourceWatcher);
+            + "ca_certificate_provider_instance is required in upstream-tls-context";
+    call.verifyRequestNack(CDS, CDS_RESOURCE, "", "0000", NODE, ImmutableList.of(errorMsg));
+    ArgumentCaptor<Status> captor = ArgumentCaptor.forClass(Status.class);
+    verify(cdsResourceWatcher).onError(captor.capture());
+    Status errorStatus = captor.getValue();
+    assertThat(errorStatus.getCode()).isEqualTo(Status.UNAVAILABLE.getCode());
+    assertThat(errorStatus.getDescription()).isEqualTo(errorMsg);
   }
 
   /**
@@ -1579,10 +1583,14 @@ public void cdsResponseErrorHandling_badTransportSocketName() {
     call.sendResponse(CDS, clusters, VERSION_1, "0000");
 
     // The response NACKed with errors indicating indices of the failed resources.
-    call.verifyRequestNack(CDS, CDS_RESOURCE, "", "0000", NODE, ImmutableList.of(
-        "CDS response Cluster 'cluster.googleapis.com' validation error: "
-            + "transport-socket with name envoy.transport_sockets.bad not supported."));
-    verifyNoInteractions(cdsResourceWatcher);
+    String errorMsg = "CDS response Cluster 'cluster.googleapis.com' validation error: "
+        + "transport-socket with name envoy.transport_sockets.bad not supported.";
+    call.verifyRequestNack(CDS, CDS_RESOURCE, "", "0000", NODE, ImmutableList.of(errorMsg));
+    ArgumentCaptor<Status> captor = ArgumentCaptor.forClass(Status.class);
+    verify(cdsResourceWatcher).onError(captor.capture());
+    Status errorStatus = captor.getValue();
+    assertThat(errorStatus.getCode()).isEqualTo(Status.UNAVAILABLE.getCode());
+    assertThat(errorStatus.getDescription()).isEqualTo(errorMsg);
   }
 
   @Test
@@ -2429,10 +2437,15 @@ public void serverSideListenerResponseErrorHandling_badDownstreamTlsContext() {
     List<Any> listeners = ImmutableList.of(Any.pack(listener));
     call.sendResponse(ResourceType.LDS, listeners, "0", "0000");
     // The response NACKed with errors indicating indices of the failed resources.
-    call.verifyRequestNack(LDS, LISTENER_RESOURCE, "", "0000", NODE, ImmutableList.of(
-            "LDS response Listener \'grpc/server?xds.resource.listening_address=0.0.0.0:7000\' "
-                + "validation error: common-tls-context is required in downstream-tls-context"));
-    verifyNoInteractions(ldsResourceWatcher);
+    String errorMsg = "LDS response Listener \'grpc/server?xds.resource.listening_address="
+        + "0.0.0.0:7000\' validation error: "
+        + "common-tls-context is required in downstream-tls-context";
+    call.verifyRequestNack(LDS, LISTENER_RESOURCE, "", "0000", NODE, ImmutableList.of(errorMsg));
+    ArgumentCaptor<Status> captor = ArgumentCaptor.forClass(Status.class);
+    verify(ldsResourceWatcher).onError(captor.capture());
+    Status errorStatus = captor.getValue();
+    assertThat(errorStatus.getCode()).isEqualTo(Status.UNAVAILABLE.getCode());
+    assertThat(errorStatus.getDescription()).isEqualTo(errorMsg);
   }
 
   @Test
@@ -2453,11 +2466,16 @@ public void serverSideListenerResponseErrorHandling_badTransportSocketName() {
     List<Any> listeners = ImmutableList.of(Any.pack(listener));
     call.sendResponse(ResourceType.LDS, listeners, "0", "0000");
     // The response NACKed with errors indicating indices of the failed resources.
+    String errorMsg = "LDS response Listener \'grpc/server?xds.resource.listening_address="
+        + "0.0.0.0:7000\' validation error: "
+        + "transport-socket with name envoy.transport_sockets.bad1 not supported.";
     call.verifyRequestNack(LDS, LISTENER_RESOURCE, "", "0000", NODE, ImmutableList.of(
-        "LDS response Listener \'grpc/server?xds.resource.listening_address=0.0.0.0:7000\' "
-            + "validation error: "
-            + "transport-socket with name envoy.transport_sockets.bad1 not supported."));
-    verifyNoInteractions(ldsResourceWatcher);
+        errorMsg));
+    ArgumentCaptor<Status> captor = ArgumentCaptor.forClass(Status.class);
+    verify(ldsResourceWatcher).onError(captor.capture());
+    Status errorStatus = captor.getValue();
+    assertThat(errorStatus.getCode()).isEqualTo(Status.UNAVAILABLE.getCode());
+    assertThat(errorStatus.getDescription()).isEqualTo(errorMsg);
   }
 
   private DiscoveryRpcCall startResourceWatcher(

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

@@ -63,15 +63,15 @@
 import io.netty.handler.codec.http2.Http2ConnectionDecoder;
 import io.netty.handler.codec.http2.Http2ConnectionEncoder;
 import io.netty.handler.codec.http2.Http2Settings;
-import java.io.IOException;
 import java.net.InetAddress;
 import java.net.InetSocketAddress;
 import java.net.SocketAddress;
 import java.util.Arrays;
 import java.util.Collections;
-import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -190,8 +190,8 @@ public void run() {
     try {
       start.get(5, TimeUnit.SECONDS);
       fail("Start should throw exception");
-    } catch (ExecutionException ex) {
-      assertThat(ex.getCause()).isInstanceOf(IOException.class);
+    } catch (TimeoutException ex) {
+      assertThat(start.isDone()).isFalse();
     }
     assertThat(selectorManager.getSelectorToUpdateSelector()).isSameInstanceAs(NO_FILTER_CHAIN);
   }
@@ -214,8 +214,8 @@ public void run() {
     try {
       start.get(5, TimeUnit.SECONDS);
       fail("Start should throw exception");
-    } catch (ExecutionException ex) {
-      assertThat(ex.getCause()).isInstanceOf(IOException.class);
+    } catch (TimeoutException ex) {
+      assertThat(start.isDone()).isFalse();
     }
     assertThat(selectorManager.getSelectorToUpdateSelector()).isSameInstanceAs(NO_FILTER_CHAIN);
   }
@@ -238,8 +238,8 @@ public void run() {
     try {
       start.get(5, TimeUnit.SECONDS);
       fail("Start should throw exception");
-    } catch (ExecutionException ex) {
-      assertThat(ex.getCause()).isInstanceOf(IOException.class);
+    } catch (TimeoutException ex) {
+      assertThat(start.isDone()).isFalse();
     }
     assertThat(selectorManager.getSelectorToUpdateSelector()).isSameInstanceAs(NO_FILTER_CHAIN);
   }

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

@@ -74,6 +74,7 @@
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
 import java.util.concurrent.atomic.AtomicReference;
 import org.junit.Before;
 import org.junit.Rule;
@@ -261,9 +262,10 @@ public void run() {
     xdsClient.ldsWatcher.onResourceDoesNotExist(ldsResource);
     try {
       start.get(5000, TimeUnit.MILLISECONDS);
-      fail("Start should throw exception");
-    } catch (ExecutionException ex) {
-      assertThat(ex.getCause()).isInstanceOf(IOException.class);
+      fail("server should not start() successfully.");
+    } catch (TimeoutException ex) {
+      // expect to block here.
+      assertThat(start.isDone()).isFalse();
     }
     verify(mockBuilder, times(1)).build();
     verify(mockServer, never()).start();
@@ -602,9 +604,10 @@ public void run() {
     xdsClient.ldsWatcher.onResourceDoesNotExist(ldsResource);
     try {
       start.get(5000, TimeUnit.MILLISECONDS);
-      fail("Start should throw exception");
-    } catch (ExecutionException ex) {
-      assertThat(ex.getCause()).isInstanceOf(IOException.class);
+      fail("server should not start()");
+    } catch (TimeoutException ex) {
+      // expect to block here.
+      assertThat(start.isDone()).isFalse();
     }
     verify(listener, times(1)).onNotServing(any(StatusException.class));
     verify(mockBuilder, times(1)).build();
@@ -627,6 +630,13 @@ public void run() {
     assertThat(sslSupplier0.isShutdown()).isTrue();
     xdsClient.deliverRdsUpdate("rds",
             Collections.singletonList(createVirtualHost("virtual-host-1")));
+    try {
+      start.get(5000, TimeUnit.MILLISECONDS);
+      fail("Start should throw exception");
+    } catch (ExecutionException ex) {
+      assertThat(ex.getCause()).isInstanceOf(IOException.class);
+      assertThat(ex.getCause().getMessage()).isEqualTo("error!");
+    }
     RdsResourceWatcher saveRdsWatcher = xdsClient.rdsWatchers.get("rds");
     assertThat(executor.forwardNanos(RETRY_DELAY_NANOS)).isEqualTo(1);
     verify(mockBuilder, times(1)).build();