From 2c5a9e2aed2a15bb46d26e445578e4172e8c6cd0 Mon Sep 17 00:00:00 2001
From: Eric Anderson <ejona@google.com>
Date: Tue, 18 Jan 2022 12:38:04 -0800
Subject: [PATCH] xds: Handle negative random numbers in c2p resolver

This was noticed because Mockito can't mock Random in Java 17, so it was
replaced with actual Random. But when doing that change it exposed that
negative numbers would cause the id to have a double '-'.
---
 .../java/io/grpc/xds/GoogleCloudToProdNameResolver.java   | 2 +-
 .../io/grpc/xds/GoogleCloudToProdNameResolverTest.java    | 8 +++-----
 2 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/xds/src/main/java/io/grpc/xds/GoogleCloudToProdNameResolver.java b/xds/src/main/java/io/grpc/xds/GoogleCloudToProdNameResolver.java
index 2845d0a00e..3ec0434a22 100644
--- a/xds/src/main/java/io/grpc/xds/GoogleCloudToProdNameResolver.java
+++ b/xds/src/main/java/io/grpc/xds/GoogleCloudToProdNameResolver.java
@@ -175,7 +175,7 @@ final class GoogleCloudToProdNameResolver extends NameResolver {
 
   private ImmutableMap<String, ?> generateBootstrap(String zone, boolean supportIpv6) {
     ImmutableMap.Builder<String, Object> nodeBuilder = ImmutableMap.builder();
-    nodeBuilder.put("id", "C2P-" + rand.nextInt());
+    nodeBuilder.put("id", "C2P-" + (rand.nextInt() & Integer.MAX_VALUE));
     if (!zone.isEmpty()) {
       nodeBuilder.put("locality", ImmutableMap.of("zone", zone));
     }
diff --git a/xds/src/test/java/io/grpc/xds/GoogleCloudToProdNameResolverTest.java b/xds/src/test/java/io/grpc/xds/GoogleCloudToProdNameResolverTest.java
index 58be710840..7c777b84bf 100644
--- a/xds/src/test/java/io/grpc/xds/GoogleCloudToProdNameResolverTest.java
+++ b/xds/src/test/java/io/grpc/xds/GoogleCloudToProdNameResolverTest.java
@@ -104,8 +104,7 @@ public class GoogleCloudToProdNameResolverTest {
 
   @Mock
   private NameResolver.Listener2 mockListener;
-  @Mock
-  private Random mockRandom;
+  private Random random = new Random(1);
   @Captor
   private ArgumentCaptor<Status> errorCaptor;
   private boolean originalIsOnGcp;
@@ -114,7 +113,6 @@ public class GoogleCloudToProdNameResolverTest {
 
   @Before
   public void setUp() {
-    when(mockRandom.nextInt()).thenReturn(123456789);
     nsRegistry.register(new FakeNsProvider("dns"));
     nsRegistry.register(new FakeNsProvider("xds"));
     originalIsOnGcp = GoogleCloudToProdNameResolver.isOnGcp;
@@ -146,7 +144,7 @@ public class GoogleCloudToProdNameResolverTest {
       }
     };
     resolver = new GoogleCloudToProdNameResolver(
-        TARGET_URI, args, fakeExecutorResource, mockRandom, fakeXdsClientPoolFactory,
+        TARGET_URI, args, fakeExecutorResource, random, fakeXdsClientPoolFactory,
         nsRegistry.asFactory());
     resolver.setHttpConnectionProvider(httpConnections);
   }
@@ -183,7 +181,7 @@ public class GoogleCloudToProdNameResolverTest {
     Map<String, ?> bootstrap = fakeXdsClientPoolFactory.bootstrapRef.get();
     Map<String, ?> node = (Map<String, ?>) bootstrap.get("node");
     assertThat(node).containsExactly(
-        "id", "C2P-123456789",
+        "id", "C2P-991614323",
         "locality", ImmutableMap.of("zone", ZONE),
         "metadata", ImmutableMap.of("TRAFFICDIRECTOR_DIRECTPATH_C2P_IPV6_CAPABLE", true));
     Map<String, ?> server = Iterables.getOnlyElement(