Introduce XdsExtensionRegistry

it/xds-client/src/test/java/com/linecorp/armeria/xds/it/PreprocessorErrorTest.java

@@ -100,7 +100,7 @@ static Stream<Arguments> testCases() {
                                         port_value: 8081
                         """,
                         IllegalArgumentException.class,
-                        "No route has been selected for listener "
+                        "No route for listener "
                 ),
                 Arguments.of(
                         //language=YAML

it/xds-client/src/test/java/com/linecorp/armeria/xds/it/VirtualHostRoutingTest.java

@@ -289,7 +289,7 @@ void noMatchTest() {
                     .isInstanceOf(UnprocessedRequestException.class)
                     .cause()
                     .isInstanceOf(IllegalArgumentException.class)
-                    .hasMessageStartingWith("No route has been selected for listener");
+                    .hasMessageStartingWith("No route for listener");
         }
     }
 }

xds/src/main/java/com/linecorp/armeria/xds/ClusterResourceParser.java

@@ -17,7 +17,6 @@
 package com.linecorp.armeria.xds;
 
 import io.envoyproxy.envoy.config.cluster.v3.Cluster;
-import io.envoyproxy.envoy.config.cluster.v3.Cluster.EdsClusterConfig;
 
 final class ClusterResourceParser extends ResourceParser<Cluster, ClusterXdsResource> {
 
@@ -26,13 +25,8 @@ final class ClusterResourceParser extends ResourceParser<Cluster, ClusterXdsReso
     private ClusterResourceParser() {}
 
     @Override
-    ClusterXdsResource parse(Cluster cluster, String version) {
-        final ClusterXdsResource resource = new ClusterXdsResource(cluster, version);
-        if (cluster.hasEdsClusterConfig()) {
-            final EdsClusterConfig eds = cluster.getEdsClusterConfig();
-            XdsConverterUtil.validateConfigSource(eds.getEdsConfig());
-        }
-        return resource;
+    ClusterXdsResource parse(Cluster cluster, XdsExtensionRegistry registry, String version) {
+        return new ClusterXdsResource(cluster, version);
     }
 
     @Override

xds/src/main/java/com/linecorp/armeria/xds/ClusterXdsResource.java

@@ -16,13 +16,9 @@
 
 package com.linecorp.armeria.xds;
 
-import static com.google.common.base.Preconditions.checkArgument;
-
-import com.linecorp.armeria.common.annotation.Nullable;
 import com.linecorp.armeria.common.annotation.UnstableApi;
 
 import io.envoyproxy.envoy.config.cluster.v3.Cluster;
-import io.envoyproxy.envoy.extensions.transport_sockets.tls.v3.UpstreamTlsContext;
 
 /**
  * A resource object for a {@link Cluster}.
@@ -31,8 +27,6 @@
 public final class ClusterXdsResource extends AbstractXdsResource {
 
     private final Cluster cluster;
-    @Nullable
-    UpstreamTlsContext upstreamTlsContext;
 
     ClusterXdsResource(Cluster cluster) {
         this(cluster, "");
@@ -44,33 +38,7 @@ public final class ClusterXdsResource extends AbstractXdsResource {
 
     private ClusterXdsResource(Cluster cluster, String version, long revision) {
         super(version, revision);
-        XdsValidatorIndexRegistry.assertValid(cluster);
         this.cluster = cluster;
-        upstreamTlsContext = upstreamTlsContext(cluster);
-    }
-
-    @Nullable
-    private static UpstreamTlsContext upstreamTlsContext(Cluster cluster) {
-        if (cluster.hasTransportSocket()) {
-            final String transportSocketName = cluster.getTransportSocket().getName();
-            checkArgument("envoy.transport_sockets.tls".equals(transportSocketName),
-                          "Unexpected tls transport socket name '%s'", transportSocketName);
-            if (!cluster.getTransportSocket().hasTypedConfig()) {
-                return UpstreamTlsContext.getDefaultInstance();
-            }
-            return XdsValidatorIndexRegistry.unpack(cluster.getTransportSocket().getTypedConfig(),
-                                                    UpstreamTlsContext.class);
-        }
-        return null;
-    }
-
-    /**
-     * The upstream TLS context extracted from {@link Cluster#getTransportSocket()}.
-     */
-    @Nullable
-    @UnstableApi
-    public UpstreamTlsContext upstreamTlsContext() {
-        return upstreamTlsContext;
     }
 
     @Override

xds/src/main/java/com/linecorp/armeria/xds/ConfigSourceClient.java

@@ -50,7 +50,8 @@ final class ConfigSourceClient implements SafeCloseable {
                        EventExecutor eventLoop,
                        Node node, BootstrapClusters bootstrapClusters,
                        ConfigSourceMapper configSourceMapper, MeterRegistry meterRegistry,
-                       MeterIdPrefix meterIdPrefix) {
+                       MeterIdPrefix meterIdPrefix,
+                       XdsExtensionRegistry extensionRegistry) {
         final ApiConfigSource apiConfigSource;
         if (configSource.hasAds()) {
             apiConfigSource = configSourceMapper.bootstrapAdsConfig();
@@ -87,7 +88,8 @@ final class ConfigSourceClient implements SafeCloseable {
                               apiType == ApiType.AGGREGATED_DELTA_GRPC;
 
         final long fetchTimeoutMillis = initialFetchTimeoutMillis(configSource);
-        stateCoordinator = new StateCoordinator(eventLoop, fetchTimeoutMillis, isDelta);
+        stateCoordinator = new StateCoordinator(eventLoop, fetchTimeoutMillis, isDelta,
+                                                extensionRegistry);
         final Backoff backoff = Backoff.ofDefault();
         if (isAds) {
             final ConfigSourceLifecycleObserver lifecycleObserver = metersFunction.apply("ads");

xds/src/main/java/com/linecorp/armeria/xds/ControlPlaneClientManager.java

@@ -37,19 +37,22 @@ final class ControlPlaneClientManager implements SafeCloseable {
     private final ConfigSourceMapper configSourceMapper;
     private final MeterRegistry meterRegistry;
     private final MeterIdPrefix meterIdPrefix;
+    private final XdsExtensionRegistry extensionRegistry;
     private final Map<ConfigSource, ConfigSourceClient> clientMap = new HashMap<>();
     private boolean closed;
 
     ControlPlaneClientManager(Bootstrap bootstrap, EventExecutor eventLoop,
                               BootstrapClusters bootstrapClusters,
                               ConfigSourceMapper configSourceMapper,
-                              MeterRegistry meterRegistry, MeterIdPrefix meterIdPrefix) {
+                              MeterRegistry meterRegistry, MeterIdPrefix meterIdPrefix,
+                              XdsExtensionRegistry extensionRegistry) {
         bootstrapNode = bootstrap.getNode();
         this.eventLoop = eventLoop;
         this.bootstrapClusters = bootstrapClusters;
         this.configSourceMapper = configSourceMapper;
         this.meterRegistry = meterRegistry;
         this.meterIdPrefix = meterIdPrefix;
+        this.extensionRegistry = extensionRegistry;
     }
 
     void subscribe(ResourceNode<?> node) {
@@ -65,7 +68,7 @@ void subscribe(ResourceNode<?> node) {
         final ConfigSourceClient client = clientMap.computeIfAbsent(
                 configSource, ignored -> new ConfigSourceClient(
                         configSource, eventLoop, bootstrapNode, bootstrapClusters, configSourceMapper,
-                        meterRegistry, meterIdPrefix));
+                        meterRegistry, meterIdPrefix, extensionRegistry));
         client.addSubscriber(type, name, node);
     }
 

xds/src/main/java/com/linecorp/armeria/xds/DefaultSubscriptionContext.java

@@ -33,12 +33,14 @@ final class DefaultSubscriptionContext implements SubscriptionContext {
     private final DirectoryWatchService watchService;
     private final BootstrapSecrets bootstrapSecrets;
     private final ResourceNodeMeterBinderFactory meterBinderFactory;
+    private final XdsExtensionRegistry extensionRegistry;
 
     DefaultSubscriptionContext(EventExecutor eventLoop, XdsClusterManager clusterManager,
                                ConfigSourceMapper configSourceMapper,
                                ControlPlaneClientManager controlPlaneClientManager,
                                MeterRegistry meterRegistry, MeterIdPrefix meterIdPrefix,
-                               DirectoryWatchService watchService, BootstrapSecrets bootstrapSecrets) {
+                               DirectoryWatchService watchService, BootstrapSecrets bootstrapSecrets,
+                               XdsExtensionRegistry extensionRegistry) {
         this.eventLoop = eventLoop;
         this.clusterManager = clusterManager;
         this.configSourceMapper = configSourceMapper;
@@ -47,6 +49,7 @@ final class DefaultSubscriptionContext implements SubscriptionContext {
         this.meterIdPrefix = meterIdPrefix;
         this.watchService = watchService;
         this.bootstrapSecrets = bootstrapSecrets;
+        this.extensionRegistry = extensionRegistry;
         meterBinderFactory = new ResourceNodeMeterBinderFactory(meterRegistry, meterIdPrefix);
     }
 
@@ -99,4 +102,9 @@ public BootstrapSecrets bootstrapSecrets() {
     public ResourceNodeMeterBinderFactory meterBinderFactory() {
         return meterBinderFactory;
     }
+
+    @Override
+    public XdsExtensionRegistry extensionRegistry() {
+        return extensionRegistry;
+    }
 }

xds/src/main/java/com/linecorp/armeria/xds/DeltaActualStream.java

@@ -29,7 +29,6 @@
 import org.slf4j.LoggerFactory;
 
 import com.google.common.collect.ImmutableSet;
-import com.google.protobuf.Message;
 import com.google.rpc.Code;
 import com.google.rpc.Status;
 
@@ -248,11 +247,12 @@ public void onCompleted() {
         owner.retryOrClose(false);
     }
 
-    private <I extends Message, O extends XdsResource> void handleResponse(
-            ResourceParser<I, O> resourceParser, DeltaDiscoveryResponse response) {
+    private void handleResponse(ResourceParser<?, ?> resourceParser, DeltaDiscoveryResponse response) {
         final XdsType type = resourceParser.type();
         final List<Resource> deltaResources = response.getResourcesList();
-        final ParsedResourcesHolder holder = resourceParser.parseDeltaResources(deltaResources);
+        final ParsedResourcesHolder holder =
+                resourceParser.parseDeltaResources(deltaResources,
+                                                   stateCoordinator.extensionRegistry());
 
         if (!holder.errors().isEmpty()) {
             holder.invalidResources().forEach((name, error) ->

xds/src/main/java/com/linecorp/armeria/xds/EndpointResourceParser.java

@@ -25,7 +25,8 @@ final class EndpointResourceParser extends ResourceParser<ClusterLoadAssignment,
     private EndpointResourceParser() {}
 
     @Override
-    EndpointXdsResource parse(ClusterLoadAssignment message, String version) {
+    EndpointXdsResource parse(ClusterLoadAssignment message, XdsExtensionRegistry registry,
+                              String version) {
         return new EndpointXdsResource(message, version);
     }
 

xds/src/main/java/com/linecorp/armeria/xds/EndpointXdsResource.java

@@ -34,7 +34,6 @@ public final class EndpointXdsResource extends AbstractXdsResource {
 
     private EndpointXdsResource(ClusterLoadAssignment clusterLoadAssignment, String version, long revision) {
         super(version, revision);
-        XdsValidatorIndexRegistry.assertValid(clusterLoadAssignment);
         this.clusterLoadAssignment = clusterLoadAssignment;
     }
 

xds/src/main/java/com/linecorp/armeria/xds/FilterUtil.java

@@ -30,11 +30,9 @@
 import com.linecorp.armeria.client.ClientPreprocessorsBuilder;
 import com.linecorp.armeria.common.annotation.Nullable;
 import com.linecorp.armeria.xds.filter.HttpFilterFactory;
-import com.linecorp.armeria.xds.filter.HttpFilterFactoryRegistry;
 import com.linecorp.armeria.xds.filter.XdsHttpFilter;
 
 import io.envoyproxy.envoy.config.route.v3.RetryPolicy;
-import io.envoyproxy.envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager;
 import io.envoyproxy.envoy.extensions.filters.network.http_connection_manager.v3.HttpFilter;
 import io.envoyproxy.envoy.extensions.filters.network.http_connection_manager.v3.HttpFilter.ConfigTypeCase;
 
@@ -50,15 +48,16 @@ static Map<String, Any> mergeFilterConfigs(
     }
 
     static ClientPreprocessors buildDownstreamFilter(
-            @Nullable HttpConnectionManager connectionManager) {
-        if (connectionManager == null) {
+            XdsExtensionRegistry extensionRegistry,
+            List<HttpFilter> httpFilters, Map<String, Any> filterConfigs) {
+        if (httpFilters.isEmpty()) {
             return ClientPreprocessors.of();
         }
-        final List<HttpFilter> httpFilters = connectionManager.getHttpFiltersList();
         final ClientPreprocessorsBuilder builder = ClientPreprocessors.builder();
         for (int i = httpFilters.size() - 1; i >= 0; i--) {
             final HttpFilter httpFilter = httpFilters.get(i);
-            final XdsHttpFilter instance = resolveInstance(httpFilter, null);
+            final Any perRouteConfig = filterConfigs.get(httpFilter.getName());
+            final XdsHttpFilter instance = resolveInstance(extensionRegistry, httpFilter, perRouteConfig);
             if (instance == null) {
                 continue;
             }
@@ -69,13 +68,14 @@ static ClientPreprocessors buildDownstreamFilter(
     }
 
     static ClientDecoration buildUpstreamFilter(
+            XdsExtensionRegistry extensionRegistry,
             List<HttpFilter> httpFilters, Map<String, Any> filterConfigs,
             @Nullable RetryPolicy retryPolicy) {
         final ClientDecorationBuilder builder = ClientDecoration.builder();
         for (int i = httpFilters.size() - 1; i >= 0; i--) {
             final HttpFilter httpFilter = httpFilters.get(i);
             final Any perRouteConfig = filterConfigs.get(httpFilter.getName());
-            final XdsHttpFilter instance = resolveInstance(httpFilter, perRouteConfig);
+            final XdsHttpFilter instance = resolveInstance(extensionRegistry, httpFilter, perRouteConfig);
             if (instance == null) {
                 continue;
             }
@@ -90,15 +90,18 @@ static ClientDecoration buildUpstreamFilter(
     }
 
     @Nullable
-    private static XdsHttpFilter resolveInstance(
+    static XdsHttpFilter resolveInstance(
+            XdsExtensionRegistry extensionRegistry,
             HttpFilter httpFilter, @Nullable Any perRouteConfig) {
-        final HttpFilterFactory filterFactory =
-                HttpFilterFactoryRegistry.filterFactory(httpFilter.getName());
-        if (filterFactory == null) {
+        final Any defaultConfig = httpFilter.getTypedConfig();
+        final Any filterConfig = perRouteConfig != null ? perRouteConfig : defaultConfig;
+        final HttpFilterFactory factory = extensionRegistry.query(
+                filterConfig, httpFilter.getName(), HttpFilterFactory.class);
+        if (factory == null) {
             if (!httpFilter.getIsOptional()) {
                 throw new IllegalArgumentException(
                         "Unknown HTTP filter '" + httpFilter.getName() +
-                        "': no HttpFilterFactory registered. Register an SPI " +
+                        "': no HttpFilterFactory registered. Register an " +
                         "HttpFilterFactory implementation to handle this filter.");
             }
             return null;
@@ -107,9 +110,7 @@ private static XdsHttpFilter resolveInstance(
                       httpFilter.getConfigTypeCase() == ConfigTypeCase.CONFIGTYPE_NOT_SET,
                       "Only 'typed_config' is supported, but '%s' was supplied",
                       httpFilter.getConfigTypeCase());
-        final Any effectiveConfig =
-                perRouteConfig != null ? perRouteConfig : httpFilter.getTypedConfig();
-        return filterFactory.create(httpFilter, effectiveConfig);
+        return factory.create(httpFilter, filterConfig, extensionRegistry.validator());
     }
 
     private FilterUtil() {}

xds/src/main/java/com/linecorp/armeria/xds/HttpConnectionManagerFactory.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2026 LY Corporation
+ *
+ * LY Corporation licenses this file to you under the Apache License,
+ * version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at:
+ *
+ *   https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ */
+
+package com.linecorp.armeria.xds;
+
+import java.util.List;
+
+import com.google.common.collect.ImmutableList;
+import com.google.protobuf.Any;
+
+import io.envoyproxy.envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager;
+
+final class HttpConnectionManagerFactory implements XdsExtensionFactory {
+
+    static final HttpConnectionManagerFactory INSTANCE = new HttpConnectionManagerFactory();
+    private static final String NAME = "envoy.http_connection_manager";
+    private static final String TYPE_URL =
+            "type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3" +
+            ".HttpConnectionManager";
+    private static final List<String> TYPE_URLS = ImmutableList.of(TYPE_URL);
+
+    private HttpConnectionManagerFactory() {}
+
+    @Override
+    public String name() {
+        return NAME;
+    }
+
+    @Override
+    public List<String> typeUrls() {
+        return TYPE_URLS;
+    }
+
+    HttpConnectionManager create(Any config, XdsResourceValidator validator) {
+        return validator.unpack(config, HttpConnectionManager.class);
+    }
+}

xds/src/main/java/com/linecorp/armeria/xds/ListenerManager.java

@@ -61,7 +61,9 @@ private void initializeBootstrap(Bootstrap bootstrap, SubscriptionContext bootst
     void register(Listener listener, SubscriptionContext context, SnapshotWatcher<Object> watcher) {
         checkArgument(!nodes.containsKey(listener.getName()),
                       "Static listener with name '%s' already registered", listener.getName());
-        final ListenerStream node = new ListenerStream(new ListenerXdsResource(listener), context);
+        final ListenerXdsResource listenerResource =
+                ListenerResourceParser.INSTANCE.parse(listener, context.extensionRegistry(), "");
+        final ListenerStream node = new ListenerStream(listenerResource, context);
         nodes.put(listener.getName(), node);
         eventLoop.execute(safeRunnable(() -> {
             final Subscription subscription = node.subscribe(watcher);