Add status/selfDiscovered endpoint to indexer for self discovery of indexer (#10679)

Added the status/selfDiscovered endpoint to indexer. Per the api-reference doc, all services support status/selfDiscovered endpoint. So this change would fix that expected behavior.

Also added example config files for indexer process that can be used to spin up the indexer process.

examples/conf/druid/cluster/data/indexer/jvm.config

@@ -0,0 +1,9 @@
+-server
+-Xms4g
+-Xmx4g
+-XX:MaxDirectMemorySize=4g
+-XX:+ExitOnOutOfMemoryError
+-Duser.timezone=UTC
+-Dfile.encoding=UTF-8
+-Djava.io.tmpdir=var/tmp
+-Djava.util.logging.manager=org.apache.logging.log4j.jul.LogManager

examples/conf/druid/cluster/data/indexer/main.config

@@ -0,0 +1 @@
+org.apache.druid.cli.Main server indexer

examples/conf/druid/cluster/data/indexer/runtime.properties

@@ -0,0 +1,38 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF 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
+#
+#   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.
+#
+
+druid.service=druid/indexer
+druid.plaintextPort=8091
+
+# Number of tasks per indexer
+druid.worker.capacity=4
+
+# Task launch parameters
+druid.indexer.task.baseTaskDir=var/druid/task
+
+# HTTP server threads
+druid.server.http.numThreads=60
+
+# Processing threads and buffers on Indexer
+druid.processing.numMergeBuffers=2
+druid.processing.buffer.sizeBytes=100MiB
+druid.processing.numThreads=4
+
+# Hadoop indexing
+druid.indexer.task.hadoopWorkingPath=var/druid/hadoop-tmp

services/src/main/java/org/apache/druid/cli/CliIndexer.java

@@ -22,6 +22,7 @@ package org.apache.druid.cli;
 import com.google.common.collect.ImmutableList;
 import com.google.inject.Binder;
 import com.google.inject.Inject;
+import com.google.inject.Key;
 import com.google.inject.Module;
 import com.google.inject.Provides;
 import com.google.inject.name.Names;
@@ -72,6 +73,7 @@ import org.apache.druid.server.coordination.ServerType;
 import org.apache.druid.server.coordination.ZkCoordinator;
 import org.apache.druid.server.http.HistoricalResource;
 import org.apache.druid.server.http.SegmentListerResource;
+import org.apache.druid.server.http.SelfDiscoveryResource;
 import org.apache.druid.server.initialization.jetty.CliIndexerServerModule;
 import org.apache.druid.server.initialization.jetty.JettyServerInitializer;
 import org.eclipse.jetty.server.Server;
@@ -168,6 +170,9 @@ public class CliIndexer extends ServerRunnable
                     )
                     .build()
             );
+
+            Jerseys.addResource(binder, SelfDiscoveryResource.class);
+            LifecycleModule.registerKey(binder, Key.get(SelfDiscoveryResource.class));
           }
 
           @Provides