xds: Fix LBs blindly propagating XdsClient errors

This is similar to 2a45524 (for #8950) but for additional similar cases.

Author: ejona86

xds/src/main/java/io/grpc/xds/CdsLoadBalancer2.java

@@ -246,7 +246,12 @@ void shutdown() {
  }
 
  @Override
- public void onError(final Status error) {
+ public void onError(Status error) {
+ Status status = Status.UNAVAILABLE
+ .withDescription(
+ String.format("Unable to load CDS %s. xDS server returned: %s: %s",
+ name, error.getCode(), error.getDescription()))
+ .withCause(error.getCause());
  syncContext.execute(new Runnable() {
  @Override
  public void run() {
@@ -255,7 +260,7 @@ public void run() {
  }
  // All watchers should receive the same error, so we only propagate it once.
  if (ClusterState.this == root) {
- handleClusterDiscoveryError(error);
+ handleClusterDiscoveryError(status);
  }
  }
  });

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

@@ -461,7 +461,11 @@ public void run() {
  if (shutdown) {
  return;
  }
- status = error;
+ String resourceName = edsServiceName != null ? edsServiceName : name;
+ status = Status.UNAVAILABLE
+ .withDescription(String.format("Unable to load EDS %s. xDS server returned: %s: %s",
+ resourceName, error.getCode(), error.getDescription()))
+ .withCause(error.getCause());
  logger.log(XdsLogLevel.WARNING, "Received EDS error: {0}", error);
  handleEndpointResolutionError();
  }

xds/src/test/java/io/grpc/xds/CdsLoadBalancer2Test.java

@@ -459,7 +459,10 @@ public void aggregateCluster_discoveryErrorBeforeChildLbCreated_returnErrorPicke
  xdsClient.deliverError(error);
  verify(helper).updateBalancingState(
  eq(ConnectivityState.TRANSIENT_FAILURE), pickerCaptor.capture());
- assertPicker(pickerCaptor.getValue(), error, null);
+ Status expectedError = Status.UNAVAILABLE.withDescription(
+ "Unable to load CDS cluster-foo.googleapis.com. xDS server returned: "
+ + "RESOURCE_EXHAUSTED: OOM");
+ assertPicker(pickerCaptor.getValue(), expectedError, null);
  assertThat(childBalancers).isEmpty();
  }
 
@@ -481,7 +484,8 @@ public void aggregateCluster_discoveryErrorAfterChildLbCreated_propagateToChildL
 
  Status error = Status.RESOURCE_EXHAUSTED.withDescription("OOM");
  xdsClient.deliverError(error);
- assertThat(childLb.upstreamError).isEqualTo(error);
+ assertThat(childLb.upstreamError.getCode()).isEqualTo(Status.Code.UNAVAILABLE);
+ assertThat(childLb.upstreamError.getDescription()).contains("RESOURCE_EXHAUSTED: OOM");
  assertThat(childLb.shutdown).isFalse(); // child LB may choose to keep working
  }
 

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

@@ -850,6 +850,24 @@ public void resolutionErrorBeforeChildLbCreated_returnErrorPickerIfAllClustersEn
  null);
  }
 
+ @Test
+ public void resolutionErrorBeforeChildLbCreated_edsOnly_returnErrorPicker() {
+ ClusterResolverConfig config = new ClusterResolverConfig(
+ Arrays.asList(edsDiscoveryMechanism1), roundRobin);
+ deliverLbConfig(config);
+ assertThat(xdsClient.watchers.keySet()).containsExactly(EDS_SERVICE_NAME1);
+ assertThat(childBalancers).isEmpty();
+ reset(helper);
+ xdsClient.deliverError(Status.RESOURCE_EXHAUSTED.withDescription("OOM"));
+ assertThat(childBalancers).isEmpty();
+ verify(helper).updateBalancingState(
+ eq(ConnectivityState.TRANSIENT_FAILURE), pickerCaptor.capture());
+ PickResult result = pickerCaptor.getValue().pickSubchannel(mock(PickSubchannelArgs.class));
+ Status actualStatus = result.getStatus();
+ assertThat(actualStatus.getCode()).isEqualTo(Status.Code.UNAVAILABLE);
+ assertThat(actualStatus.getDescription()).contains("RESOURCE_EXHAUSTED: OOM");
+ }
+
  @Test
  public void handleNameResolutionErrorFromUpstream_beforeChildLbCreated_returnErrorPicker() {
  ClusterResolverConfig config = new ClusterResolverConfig(