Add tool elasticsearch-node unsafe-bootstrap (#37696)

elasticsearch-node tool helps to restore cluster if half or more of
master eligible nodes are lost. Of course, all bets are off, regarding
data consistency.

There are two parts of the tool: unsafe-bootstrap to be used when there
is still at least one master-eligible node alive and detach-cluster,
when there are no master-eligible nodes left.
This commit implements the first part.

Docs for the tool will be added separately as a part of #37812.

Author: andrershov

distribution/src/bin/elasticsearch-node

@@ -0,0 +1,5 @@
+#!/bin/bash
+
+ES_MAIN_CLASS=org.elasticsearch.cluster.coordination.NodeToolCli \
+  "`dirname "$0"`"/elasticsearch-cli \
+  "$@"

distribution/src/bin/elasticsearch-node.bat

@@ -0,0 +1,12 @@
+@echo off
+
+setlocal enabledelayedexpansion
+setlocal enableextensions
+
+set ES_MAIN_CLASS=org.elasticsearch.cluster.coordination.NodeToolCli
+call "%~dp0elasticsearch-cli.bat" ^
+  %%* ^
+  || exit /b 1
+
+endlocal
+endlocal

qa/vagrant/src/main/java/org/elasticsearch/packaging/test/ArchiveTestCase.java

@@ -301,7 +301,7 @@ public void test90SecurityCliPackaging() {
         }
     }
 
-    public void test100RepairIndexCliPackaging() {
+    public void test100ElasticsearchShardCliPackaging() {
         assumeThat(installation, is(notNullValue()));
 
         final Installation.Executables bin = installation.executables();
@@ -318,4 +318,22 @@ public void test100RepairIndexCliPackaging() {
         }
     }
 
+    public void test110ElasticsearchNodeCliPackaging() {
+        assumeThat(installation, is(notNullValue()));
+
+        final Installation.Executables bin = installation.executables();
+        final Shell sh = new Shell();
+
+        Platforms.PlatformAction action = () -> {
+            final Result result = sh.run(bin.elasticsearchNode + " -h");
+            assertThat(result.stdout,
+                    containsString("A CLI tool to unsafely recover a cluster after the permanent loss of too many master-eligible nodes"));
+        };
+
+        if (distribution().equals(Distribution.DEFAULT_TAR) || distribution().equals(Distribution.DEFAULT_ZIP)) {
+            Platforms.onLinux(action);
+            Platforms.onWindows(action);
+        }
+    }
+
 }

qa/vagrant/src/main/java/org/elasticsearch/packaging/util/Archives.java

@@ -186,7 +186,8 @@ private static void verifyOssInstallation(Installation es, Distribution distribu
             "elasticsearch-env",
             "elasticsearch-keystore",
             "elasticsearch-plugin",
-            "elasticsearch-shard"
+            "elasticsearch-shard",
+            "elasticsearch-node"
         ).forEach(executable -> {
 
             assertThat(es.bin(executable), file(File, owner, owner, p755));

qa/vagrant/src/main/java/org/elasticsearch/packaging/util/Installation.java

@@ -102,6 +102,7 @@ public class Executables {
         public final Path elasticsearchKeystore = platformExecutable("elasticsearch-keystore");
         public final Path elasticsearchCertutil = platformExecutable("elasticsearch-certutil");
         public final Path elasticsearchShard = platformExecutable("elasticsearch-shard");
+        public final Path elasticsearchNode = platformExecutable("elasticsearch-node");
 
         private Path platformExecutable(String name) {
             final String platformExecutableName = Platforms.WINDOWS

qa/vagrant/src/main/java/org/elasticsearch/packaging/util/Packages.java

@@ -196,7 +196,8 @@ private static void verifyOssInstallation(Installation es, Distribution distribu
             "elasticsearch",
             "elasticsearch-plugin",
             "elasticsearch-keystore",
-            "elasticsearch-shard"
+            "elasticsearch-shard",
+            "elasticsearch-node"
         ).forEach(executable -> assertThat(es.bin(executable), file(File, "root", "root", p755)));
 
         Stream.of(

qa/vagrant/src/test/resources/packaging/utils/packages.bash

@@ -104,6 +104,7 @@ verify_package_installation() {
     assert_file "$ESHOME/bin/elasticsearch" f root root 755
     assert_file "$ESHOME/bin/elasticsearch-plugin" f root root 755
     assert_file "$ESHOME/bin/elasticsearch-shard" f root root 755
+    assert_file "$ESHOME/bin/elasticsearch-node" f root root 755
     assert_file "$ESHOME/lib" d root root 755
     assert_file "$ESCONFIG" d root elasticsearch 2750
     assert_file "$ESCONFIG/elasticsearch.keystore" f root elasticsearch 660

qa/vagrant/src/test/resources/packaging/utils/tar.bash

@@ -95,6 +95,7 @@ verify_archive_installation() {
     assert_file "$ESHOME/bin/elasticsearch-keystore" f elasticsearch elasticsearch 755
     assert_file "$ESHOME/bin/elasticsearch-plugin" f elasticsearch elasticsearch 755
     assert_file "$ESHOME/bin/elasticsearch-shard" f elasticsearch elasticsearch 755
+    assert_file "$ESHOME/bin/elasticsearch-node" f elasticsearch elasticsearch 755
     assert_file "$ESCONFIG" d elasticsearch elasticsearch 755
     assert_file "$ESCONFIG/elasticsearch.yml" f elasticsearch elasticsearch 660
     assert_file "$ESCONFIG/jvm.options" f elasticsearch elasticsearch 660

server/src/main/java/org/elasticsearch/cli/CommandLoggingConfigurator.java

@@ -27,13 +27,13 @@
  * Holder class for method to configure logging without Elasticsearch configuration files for use in CLI tools that will not read such
  * files.
  */
-final class CommandLoggingConfigurator {
+public final class CommandLoggingConfigurator {
 
     /**
      * Configures logging without Elasticsearch configuration files based on the system property "es.logger.level" only. As such, any
      * logging will be written to the console.
      */
-    static void configureLoggingWithoutConfig() {
+    public static void configureLoggingWithoutConfig() {
         // initialize default for es.logger.level because we will not read the log4j2.properties
         final String loggerLevel = System.getProperty("es.logger.level", Level.INFO.name());
         final Settings settings = Settings.builder().put("logger.level", loggerLevel).build();

server/src/main/java/org/elasticsearch/cluster/coordination/NodeToolCli.java

@@ -0,0 +1,44 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch 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.
+ */
+package org.elasticsearch.cluster.coordination;
+
+import org.elasticsearch.cli.CommandLoggingConfigurator;
+import org.elasticsearch.cli.MultiCommand;
+import org.elasticsearch.cli.Terminal;
+
+// NodeToolCli does not extend LoggingAwareCommand, because LoggingAwareCommand performs logging initialization
+// after LoggingAwareCommand instance is constructed.
+// It's too late for us, because before UnsafeBootstrapMasterCommand is added to the list of subcommands
+// log4j2 initialization will happen, because it has static reference to Logger class.
+// Even if we avoid making a static reference to Logger class, there is no nice way to avoid declaring
+// UNSAFE_BOOTSTRAP, which depends on ClusterService, which in turn has static Logger.
+// TODO execute CommandLoggingConfigurator.configureLoggingWithoutConfig() in the constructor of commands, not in beforeMain
+public class NodeToolCli extends MultiCommand {
+
+    public NodeToolCli() {
+        super("A CLI tool to unsafely recover a cluster after the permanent loss of too many master-eligible nodes", ()->{});
+        CommandLoggingConfigurator.configureLoggingWithoutConfig();
+        subcommands.put("unsafe-bootstrap", new UnsafeBootstrapMasterCommand());
+    }
+
+    public static void main(String[] args) throws Exception {
+        exit(new NodeToolCli().main(args, Terminal.DEFAULT));
+    }
+
+}