xds: fix XdsNameResolver blindly propagates XdsClient errors (#8953)

Author: YifeiZhuang

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

@@ -722,7 +722,9 @@ public void run() {
  if (stopped || receivedConfig) {
  return;
  }
- listener.onError(error);
+ listener.onError(Status.UNAVAILABLE.withCause(error.getCause()).withDescription(
+ String.format("Unable to load LDS %s. xDS server returned: %s: %s.",
+ ldsResourceName, error.getCode(), error.getDescription())));
  }
  });
  }
@@ -920,7 +922,9 @@ public void run() {
  if (RouteDiscoveryState.this != routeDiscoveryState || receivedConfig) {
  return;
  }
- listener.onError(error);
+ listener.onError(Status.UNAVAILABLE.withCause(error.getCause()).withDescription(
+ String.format("Unable to load RDS %s. xDS server returned: %s: %s.",
+ resourceName, error.getCode(), error.getDescription())));
  }
  });
  }

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

@@ -431,7 +431,21 @@ public void resolving_encounterErrorLdsWatcherOnly() {
  verify(mockListener).onError(errorCaptor.capture());
  Status error = errorCaptor.getValue();
  assertThat(error.getCode()).isEqualTo(Code.UNAVAILABLE);
- assertThat(error.getDescription()).isEqualTo("server unreachable");
+ assertThat(error.getDescription()).isEqualTo("Unable to load LDS " + AUTHORITY
+ + ". xDS server returned: UNAVAILABLE: server unreachable.");
+ }
+
+ @Test
+ public void resolving_translateErrorLds() {
+ resolver.start(mockListener);
+ FakeXdsClient xdsClient = (FakeXdsClient) resolver.getXdsClient();
+ xdsClient.deliverError(Status.NOT_FOUND.withDescription("server unreachable"));
+ verify(mockListener).onError(errorCaptor.capture());
+ Status error = errorCaptor.getValue();
+ assertThat(error.getCode()).isEqualTo(Code.UNAVAILABLE);
+ assertThat(error.getDescription()).isEqualTo("Unable to load LDS " + AUTHORITY
+ + ". xDS server returned: NOT_FOUND: server unreachable.");
+ assertThat(error.getCause()).isNull();
  }
 
  @Test
@@ -441,10 +455,14 @@ public void resolving_encounterErrorLdsAndRdsWatchers() {
  xdsClient.deliverLdsUpdateForRdsName(RDS_RESOURCE_NAME);
  xdsClient.deliverError(Status.UNAVAILABLE.withDescription("server unreachable"));
  verify(mockListener, times(2)).onError(errorCaptor.capture());
- for (Status error : errorCaptor.getAllValues()) {
- assertThat(error.getCode()).isEqualTo(Code.UNAVAILABLE);
- assertThat(error.getDescription()).isEqualTo("server unreachable");
- }
+ Status error = errorCaptor.getAllValues().get(0);
+ assertThat(error.getCode()).isEqualTo(Code.UNAVAILABLE);
+ assertThat(error.getDescription()).isEqualTo("Unable to load LDS " + AUTHORITY
+ + ". xDS server returned: UNAVAILABLE: server unreachable.");
+ error = errorCaptor.getAllValues().get(1);
+ assertThat(error.getCode()).isEqualTo(Code.UNAVAILABLE);
+ assertThat(error.getDescription()).isEqualTo("Unable to load RDS " + RDS_RESOURCE_NAME
+ + ". xDS server returned: UNAVAILABLE: server unreachable.");
  }
 
  @Test