xds/federation: fix percent encoding on server side

Overlooked in #8857 on server side. Since `XdsNameResolver.percentEncodePath()` will be also used for server side, I moved the method to `XdsClient`.

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

@@ -24,6 +24,7 @@ import com.google.common.base.Joiner;
 import com.google.common.base.MoreObjects;
 import com.google.common.base.Splitter;
 import com.google.common.collect.ImmutableList;
+import com.google.common.net.UrlEscapers;
 import com.google.common.util.concurrent.ListenableFuture;
 import com.google.protobuf.Any;
 import io.grpc.Status;
@@ -106,6 +107,15 @@ abstract class XdsClient {
     return resourceName.replace(rawQuery, canonifiedQuery);
   }
 
+  static String percentEncodePath(String input) {
+    Iterable<String> pathSegs = Splitter.on('/').split(input);
+    List<String> encodedSegs = new ArrayList<>();
+    for (String pathSeg : pathSegs) {
+      encodedSegs.add(UrlEscapers.urlPathSegmentEscaper().escape(pathSeg));
+    }
+    return Joiner.on('/').join(encodedSegs);
+  }
+
   @AutoValue
   abstract static class LdsUpdate implements ResourceUpdate {
     // Http level api listener configuration.

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

@@ -22,12 +22,10 @@ import static io.grpc.xds.Bootstrapper.XDSTP_SCHEME;
 
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Joiner;
-import com.google.common.base.Splitter;
 import com.google.common.base.Strings;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.Sets;
-import com.google.common.net.UrlEscapers;
 import com.google.gson.Gson;
 import com.google.protobuf.util.Durations;
 import io.grpc.Attributes;
@@ -193,7 +191,7 @@ final class XdsNameResolver extends NameResolver {
     }
     String replacement = serviceAuthority;
     if (listenerNameTemplate.startsWith(XDSTP_SCHEME)) {
-      replacement = percentEncodePath(replacement);
+      replacement = XdsClient.percentEncodePath(replacement);
     }
     String ldsResourceName = expandPercentS(listenerNameTemplate, replacement);
     if (!XdsClient.isResourceNameValid(ldsResourceName, ResourceType.LDS.typeUrl())
@@ -208,16 +206,6 @@ final class XdsNameResolver extends NameResolver {
     resolveState.start();
   }
 
-  @VisibleForTesting
-  static String percentEncodePath(String input) {
-    Iterable<String> pathSegs = Splitter.on('/').split(input);
-    List<String> encodedSegs = new ArrayList<>();
-    for (String pathSeg : pathSegs) {
-      encodedSegs.add(UrlEscapers.urlPathSegmentEscaper().escape(pathSeg));
-    }
-    return Joiner.on('/').join(encodedSegs);
-  }
-
   private static String expandPercentS(String template, String replacement) {
     return template.replace("%s", replacement);
   }

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

@@ -24,7 +24,6 @@ import com.google.auto.value.AutoValue;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
-import com.google.common.net.UrlEscapers;
 import com.google.common.util.concurrent.SettableFuture;
 import io.grpc.Attributes;
 import io.grpc.InternalServerInterceptors;
@@ -196,7 +195,7 @@ final class XdsServerWrapper extends Server {
     }
     String replacement = listenerAddress;
     if (listenerTemplate.startsWith(XDSTP_SCHEME)) {
-      replacement = UrlEscapers.urlFragmentEscaper().escape(replacement);
+      replacement = XdsClient.percentEncodePath(replacement);
     }
     discoveryState = new DiscoveryState(listenerTemplate.replaceAll("%s", replacement));
   }

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

@@ -2619,6 +2619,31 @@ public class ClientXdsClientDataTest {
         .isEqualTo(expectedCanonifiedName);
   }
 
+  /**
+   *  Tests compliance with RFC 3986 section 3.3
+   *  https://datatracker.ietf.org/doc/html/rfc3986#section-3.3
+   */
+  @Test
+  public void percentEncodePath()  {
+    String unreserved = "aAzZ09-._~";
+    assertThat(XdsClient.percentEncodePath(unreserved)).isEqualTo(unreserved);
+
+    String subDelims = "!$&'(*+,;/=";
+    assertThat(XdsClient.percentEncodePath(subDelims)).isEqualTo(subDelims);
+
+    String colonAndAt = ":@";
+    assertThat(XdsClient.percentEncodePath(colonAndAt)).isEqualTo(colonAndAt);
+
+    String needBeEncoded = "?#[]";
+    assertThat(XdsClient.percentEncodePath(needBeEncoded)).isEqualTo("%3F%23%5B%5D");
+
+    String ipv4 = "0.0.0.0:8080";
+    assertThat(XdsClient.percentEncodePath(ipv4)).isEqualTo(ipv4);
+
+    String ipv6 = "[::1]:8080";
+    assertThat(XdsClient.percentEncodePath(ipv6)).isEqualTo("%5B::1%5D:8080");
+  }
+
   private static Filter buildHttpConnectionManagerFilter(HttpFilter... httpFilters) {
     return Filter.newBuilder()
         .setName("envoy.http_connection_manager")

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

@@ -1955,31 +1955,6 @@ public class XdsNameResolverTest {
         .isFalse();
   }
 
-  /**
-   *  Tests compliance with RFC 3986 section 3.3
-   *  https://datatracker.ietf.org/doc/html/rfc3986#section-3.3
-   */
-  @Test
-  public void percentEncodePath()  {
-    String unreserved = "aAzZ09-._~";
-    assertThat(XdsNameResolver.percentEncodePath(unreserved)).isEqualTo(unreserved);
-
-    String subDelims = "!$&'(*+,;/=";
-    assertThat(XdsNameResolver.percentEncodePath(subDelims)).isEqualTo(subDelims);
-
-    String colonAndAt = ":@";
-    assertThat(XdsNameResolver.percentEncodePath(colonAndAt)).isEqualTo(colonAndAt);
-
-    String needBeEncoded = "?#[]";
-    assertThat(XdsNameResolver.percentEncodePath(needBeEncoded)).isEqualTo("%3F%23%5B%5D");
-
-    String ipv4 = "0.0.0.0:8080";
-    assertThat(XdsNameResolver.percentEncodePath(ipv4)).isEqualTo(ipv4);
-
-    String ipv6 = "[::1]:8080";
-    assertThat(XdsNameResolver.percentEncodePath(ipv6)).isEqualTo("%5B::1%5D:8080");
-  }
-
   private final class FakeXdsClientPoolFactory implements XdsClientPoolFactory {
     Map<String, ?> bootstrap;