minimal impl

Author: jrhee17

it/xds-client/src/test/resources/META-INF/services/com.linecorp.armeria.xds.validator.XdsValidatorIndex

@@ -0,0 +1 @@
+com.linecorp.armeria.xds.api.StrictXdsValidatorIndex

xds-api/src/main/java/com/linecorp/armeria/xds/api/DefaultXdsValidatorIndex.java

@@ -19,37 +19,33 @@
 import com.linecorp.armeria.common.annotation.UnstableApi;
 import com.linecorp.armeria.xds.validator.XdsValidatorIndex;
 
-import io.envoyproxy.pgv.ReflectiveValidatorIndex;
-import io.envoyproxy.pgv.ValidationException;
-import io.envoyproxy.pgv.Validator;
-import io.envoyproxy.pgv.ValidatorIndex;
-
 /**
- * The default validator which uses reflection in conjunction with pgv to validate messages.
+ * The default validator which composes pgv (protoc-gen-validate) structural validation with
+ * supported-field validation.
  */
 @UnstableApi
-public final class DefaultXdsValidatorIndex implements ValidatorIndex, XdsValidatorIndex {
+public final class DefaultXdsValidatorIndex implements XdsValidatorIndex {
+
+    private static final DefaultXdsValidatorIndex INSTANCE = new DefaultXdsValidatorIndex();
 
-    private final ValidatorIndex delegate;
+    private final PgvValidator pgvValidator = PgvValidator.of();
+    private final SupportedFieldValidator supportedFieldValidator = SupportedFieldValidator.of();
 
     /**
-     * Creates a validator.
+     * Creates a validator that composes pgv and supported-field validation.
      */
-    public DefaultXdsValidatorIndex() {
-        delegate = new ReflectiveValidatorIndex();
-    }
+    public DefaultXdsValidatorIndex() {}
 
-    @Override
-    public <T> Validator<T> validatorFor(Class clazz) {
-        return delegate.validatorFor(clazz);
+    /**
+     * Returns the default singleton instance.
+     */
+    public static DefaultXdsValidatorIndex of() {
+        return INSTANCE;
     }
 
     @Override
     public void assertValid(Object message) {
-        try {
-            validatorFor(message).assertValid(message);
-        } catch (ValidationException e) {
-            throw new IllegalArgumentException(e);
-        }
+        pgvValidator.assertValid(message);
+        supportedFieldValidator.assertValid(message);
     }
 }

xds-api/src/main/java/com/linecorp/armeria/xds/api/IgnoreUnsupportedFieldHandler.java

@@ -0,0 +1,26 @@
+/*
+ * Copyright 2025 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.api;
+
+enum IgnoreUnsupportedFieldHandler implements UnsupportedFieldHandler {
+    INSTANCE;
+
+    @Override
+    public void handle(String fieldPath) {
+        // no-op
+    }
+}

xds-api/src/main/java/com/linecorp/armeria/xds/api/MeterUnsupportedFieldHandler.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2025 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.api;
+
+import static java.util.Objects.requireNonNull;
+
+import com.linecorp.armeria.common.annotation.UnstableApi;
+import com.linecorp.armeria.common.metric.MeterIdPrefix;
+
+import io.micrometer.core.instrument.Counter;
+import io.micrometer.core.instrument.MeterRegistry;
+
+/**
+ * An {@link UnsupportedFieldHandler} that records metrics for unsupported xDS field usage.
+ * A counter is incremented for each unsupported field path detected, allowing users to
+ * visualize which unsupported fields their xDS configuration relies on.
+ *
+ * <p>The counter name is {@code <prefix>.unsupported.fields} with a {@code field} tag
+ * containing the dotted field path.
+ */
+@UnstableApi
+public final class MeterUnsupportedFieldHandler implements UnsupportedFieldHandler {
+
+    private final MeterRegistry meterRegistry;
+    private final MeterIdPrefix meterIdPrefix;
+
+    /**
+     * Creates a new handler that records unsupported field metrics.
+     *
+     * @param meterRegistry the registry to record metrics in
+     * @param meterIdPrefix the prefix for meter IDs (e.g., {@code "armeria.xds"})
+     */
+    public MeterUnsupportedFieldHandler(MeterRegistry meterRegistry, MeterIdPrefix meterIdPrefix) {
+        this.meterRegistry = requireNonNull(meterRegistry, "meterRegistry");
+        this.meterIdPrefix = requireNonNull(meterIdPrefix, "meterIdPrefix");
+    }
+
+    @Override
+    public void handle(String fieldPath) {
+        final Counter counter = Counter.builder(meterIdPrefix.name("unsupported.fields"))
+                                       .tags(meterIdPrefix.tags())
+                                       .tag("field", fieldPath)
+                                       .register(meterRegistry);
+        counter.increment();
+    }
+}

xds-api/src/main/java/com/linecorp/armeria/xds/api/PgvValidator.java

@@ -0,0 +1,56 @@
+/*
+ * Copyright 2025 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.api;
+
+import com.linecorp.armeria.common.annotation.UnstableApi;
+
+import io.envoyproxy.pgv.ReflectiveValidatorIndex;
+import io.envoyproxy.pgv.ValidationException;
+import io.envoyproxy.pgv.ValidatorIndex;
+
+/**
+ * Validates xDS protobuf messages using pgv (protoc-gen-validate) structural validation.
+ */
+@UnstableApi
+public final class PgvValidator {
+
+    private static final PgvValidator INSTANCE = new PgvValidator();
+
+    private final ValidatorIndex delegate = new ReflectiveValidatorIndex();
+
+    private PgvValidator() {}
+
+    /**
+     * Returns the singleton {@link PgvValidator} instance.
+     */
+    public static PgvValidator of() {
+        return INSTANCE;
+    }
+
+    /**
+     * Validates the given message using pgv structural validation.
+     *
+     * @throws IllegalArgumentException if validation fails
+     */
+    public void assertValid(Object message) {
+        try {
+            delegate.validatorFor(message).assertValid(message);
+        } catch (ValidationException e) {
+            throw new IllegalArgumentException(e);
+        }
+    }
+}

xds-api/src/main/java/com/linecorp/armeria/xds/api/StrictXdsValidatorIndex.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2025 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.api;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import com.linecorp.armeria.common.annotation.UnstableApi;
+import com.linecorp.armeria.xds.validator.XdsValidatorIndex;
+
+/**
+ * A strict {@link XdsValidatorIndex} that composes pgv (protoc-gen-validate) structural validation
+ * with supported-field validation. All unsupported field violations are collected and reported
+ * together in a single {@link IllegalArgumentException}.
+ *
+ * <p>This validator is intended for use in test environments via SPI to catch unsupported
+ * field usage early. Its {@link #priority()} is {@code 1}, which is higher than
+ * {@link DefaultXdsValidatorIndex} ({@code 0}), so it wins SPI selection when present
+ * on the classpath.
+ */
+@UnstableApi
+public final class StrictXdsValidatorIndex implements XdsValidatorIndex {
+
+    private final PgvValidator pgvValidator = PgvValidator.of();
+
+    @Override
+    public void assertValid(Object message) {
+        pgvValidator.assertValid(message);
+        final List<String> violations = new ArrayList<>();
+        final SupportedFieldValidator validator =
+                new SupportedFieldValidator(violations::add);
+        validator.assertValid(message);
+        if (!violations.isEmpty()) {
+            throw new IllegalArgumentException(
+                    "Unsupported xDS fields detected: " + String.join(", ", violations));
+        }
+    }
+
+    @Override
+    public int priority() {
+        return 1;
+    }
+}