api: implement admin interface API (#7928)
Adds an AdminInterface API that automatically loads available admin services (currently, only supports Channelz and CSDS).
diff --git a/services/src/main/java/io/grpc/services/AdminInterface.java b/services/src/main/java/io/grpc/services/AdminInterface.java
new file mode 100644
index 0000000..32c467b
--- /dev/null
+++ b/services/src/main/java/io/grpc/services/AdminInterface.java
@@ -0,0 +1,72 @@
+/*
+ * Copyright 2021 The gRPC Authors
+ *
+ * Licensed 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
+ *
+ * http://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 io.grpc.services;
+
+import io.grpc.BindableService;
+import io.grpc.ExperimentalApi;
+import io.grpc.ServerServiceDefinition;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import javax.annotation.concurrent.ThreadSafe;
+
+/**
+ * Admin Interface provides a class of services for exposing the overall state of gRPC
+ * activity in a given binary. It aims to be a convenient API that provides available admin
+ * services.
+ */
+@ExperimentalApi("https://github.com/grpc/grpc-java/issues/7929")
+@ThreadSafe
+public final class AdminInterface {
+ private static final int DEFAULT_CHANNELZ_MAX_PAGE_SIZE = 100;
+ private static final Logger logger = Logger.getLogger(AdminInterface.class.getName());
+
+ // Do not instantiate.
+ private AdminInterface() {}
+
+ /**
+ * Returns a list of gRPC's built-in admin services.
+ *
+ * @return list of standard admin services
+ */
+ public static List<ServerServiceDefinition> getStandardServices() {
+ List<ServerServiceDefinition> services = new ArrayList<>();
+ services.add(ChannelzService.newInstance(DEFAULT_CHANNELZ_MAX_PAGE_SIZE).bindService());
+ BindableService csds = null;
+ try {
+ Class<?> clazz = Class.forName("io.grpc.xds.CsdsService");
+ Method m = clazz.getMethod("newInstance");
+ csds = (BindableService) m.invoke(null);
+ } catch (ClassNotFoundException e) {
+ logger.log(Level.FINE, "Unable to find CSDS service", e);
+ } catch (NoSuchMethodException e) {
+ logger.log(Level.FINE, "Unable to load CSDS service", e);
+ } catch (IllegalAccessException e) {
+ logger.log(Level.FINE, "Unable to load CSDS service", e);
+ } catch (InvocationTargetException e) {
+ logger.log(Level.FINE, "Unable to load CSDS service", e);
+ }
+ if (csds != null) {
+ services.add(csds.bindService());
+ }
+ return Collections.unmodifiableList(services);
+ }
+}
diff --git a/services/src/test/java/io/grpc/services/AdminInterfaceChannelzTest.java b/services/src/test/java/io/grpc/services/AdminInterfaceChannelzTest.java
new file mode 100644
index 0000000..7d7c681
--- /dev/null
+++ b/services/src/test/java/io/grpc/services/AdminInterfaceChannelzTest.java
@@ -0,0 +1,37 @@
+/*
+ * Copyright 2021 The gRPC Authors
+ *
+ * Licensed 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
+ *
+ * http://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 io.grpc.services;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import com.google.common.collect.Iterables;
+import io.grpc.ServerServiceDefinition;
+import io.grpc.channelz.v1.ChannelzGrpc;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+@RunWith(JUnit4.class)
+public class AdminInterfaceChannelzTest {
+
+ @Test
+ public void autoChannelz() {
+ ServerServiceDefinition channelz =
+ Iterables.getOnlyElement(AdminInterface.getStandardServices());
+ assertThat(channelz.getServiceDescriptor().getName()).isEqualTo(ChannelzGrpc.SERVICE_NAME);
+ }
+}
