Add a tool for creating enrollment tokens

docs/reference/commands/create-enrollment-token.asciidoc

@@ -0,0 +1,59 @@
+[roles="xpack"]
+[[create-enrollment-token]]
+
+== elasticsearch-create-enrollment-token
+
+The `elasticsearch-create-enrollment-token` command creates enrollment tokens for
+{es} nodes and {kib} instances.
+
+[discrete]
+=== Synopsis
+
+[source,shell]
+----
+bin/elasticsearch-create-enrollment-token
+[-f, --force] [-h, --help] [-E <KeyValuePair>] [-s, --scope]
+----
+
+[discrete]
+=== Description
+
+This command allows users to create enrollment tokens that can be subsequently
+used to enroll new {es} nodes to an existing cluster or configure {kib} instances
+to communicate with an existing cluster that has security features enabled.
+It uses a temporary superuser in the <<file-realm, file realm>> that is automatically
+generated and then removed, in order to run the request to create enrollment tokens.
+You cannot use this tool if the file realm has been disabled in your `elasticsearch.yml`
+file.
+
+This command uses an HTTP connection to connect to the cluster and run the user
+management requests. The command automatically attempts to establish the connection
+over HTTPS by using the `xpack.security.http.ssl` settings in
+the `elasticsearch.yml` file. If you do not use the default config directory
+location, ensure that the *ES_PATH_CONF* environment variable returns the
+correct path before you run the `elasticsearch-create-enrollment-token` command. You can
+override settings in your `elasticsearch.yml` file by using the `-E` command
+option. For more information about debugging connection failures, see
+<<trb-security-setup>>.
+
+[discrete]
+[[create-enrollment-token-parameters]]
+=== Parameters
+
+`-E <KeyValuePair>`:: Configures a standard {es} or {xpack} setting.
+
+`-f, --force`:: Forces the execution of the command against an unhealthy cluster. 
+
+`-h, --help`:: Shows help information.
+
+`-s, --scope`:: Specifies the scope of the generated token. Supported values are `node` and `kibana`.
+
+[discrete]
+=== Examples
+
+The following command creates an enrollment token to be used by an {es} node:
+
+[source,shell]
+----
+bin/elasticsearch-create-enrollment-token -s node
+----

docs/reference/commands/index.asciidoc

@@ -9,6 +9,7 @@ tasks from the command line:
 
 * <<certgen>>
 * <<certutil>>
+* <<create-enrollment-token>>
 * <<elasticsearch-croneval>>
 * <<elasticsearch-keystore>>
 * <<node-tool>>
@@ -22,6 +23,7 @@ tasks from the command line:
 
 include::certgen.asciidoc[]
 include::certutil.asciidoc[]
+include::create-enrollment-token.asciidoc[]
 include::croneval.asciidoc[]
 include::keystore.asciidoc[]
 include::node-tool.asciidoc[]

x-pack/plugin/security/src/main/bin/elasticsearch-create-enrollment-token

@@ -0,0 +1,11 @@
+#!/bin/bash
+
+# Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+# or more contributor license agreements. Licensed under the Elastic License
+# 2.0; you may not use this file except in compliance with the Elastic License
+# 2.0.
+
+ES_MAIN_CLASS=org.elasticsearch.xpack.security.enrollment.tool.CreateEnrollmentTokenTool \
+  ES_ADDITIONAL_SOURCES="x-pack-env;x-pack-security-env" \
+  "`dirname "$0"`"/elasticsearch-cli \
+  "$@"

x-pack/plugin/security/src/main/bin/elasticsearch-create-enrollment-token.bat

@@ -0,0 +1,21 @@
+@echo off
+
+rem Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+rem or more contributor license agreements. Licensed under the Elastic License
+rem 2.0; you may not use this file except in compliance with the Elastic License
+rem 2.0.
+
+setlocal enabledelayedexpansion
+setlocal enableextensions
+
+set ES_MAIN_CLASS=org.elasticsearch.xpack.security.enrollment.tool.CreateEnrollmentTokenTool
+set ES_ADDITIONAL_SOURCES=x-pack-env;x-pack-security-env
+set ES_ADDITIONAL_CLASSPATH_DIRECTORIES=lib/tools/security-cli
+call "%~dp0elasticsearch-cli.bat" ^
+  %%* ^
+  || goto exit
+
+endlocal
+endlocal
+:exit
+exit /b %ERRORLEVEL%

x-pack/plugin/security/src/main/java/org/elasticsearch/xpack/security/enrollment/tool/CreateEnrollmentTokenTool.java

@@ -0,0 +1,89 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+package org.elasticsearch.xpack.security.enrollment.tool;
+
+import joptsimple.OptionSet;
+import joptsimple.OptionSpec;
+
+import org.elasticsearch.cli.ExitCodes;
+import org.elasticsearch.cli.Terminal;
+import org.elasticsearch.cli.UserException;
+import org.elasticsearch.common.settings.KeyStoreWrapper;
+import org.elasticsearch.common.settings.SecureString;
+import org.elasticsearch.core.CheckedFunction;
+import org.elasticsearch.env.Environment;
+import org.elasticsearch.xpack.core.XPackSettings;
+import org.elasticsearch.xpack.security.enrollment.CreateEnrollmentToken;
+import org.elasticsearch.xpack.security.tool.BaseRunAsSuperuserCommand;
+import org.elasticsearch.xpack.security.tool.CommandLineHttpClient;
+
+import java.util.List;
+import java.util.function.Function;
+
+public class CreateEnrollmentTokenTool extends BaseRunAsSuperuserCommand {
+
+    private final OptionSpec<String> scope;
+    private final CheckedFunction<Environment, CreateEnrollmentToken, Exception> createEnrollmentTokenFunction;
+    static final List<String> ALLOWED_SCOPES = List.of("node", "kibana");
+
+    CreateEnrollmentTokenTool() {
+        this(
+            environment -> new CommandLineHttpClient(environment),
+            environment -> KeyStoreWrapper.load(environment.configFile()),
+            environment -> new CreateEnrollmentToken(environment)
+        );
+    }
+
+    CreateEnrollmentTokenTool(
+        Function<Environment, CommandLineHttpClient> clientFunction,
+        CheckedFunction<Environment, KeyStoreWrapper, Exception> keyStoreFunction,
+        CheckedFunction<Environment, CreateEnrollmentToken, Exception> createEnrollmentTokenFunction
+    ) {
+        super(clientFunction, keyStoreFunction, "Creates enrollment tokens for elasticsearch nodes and kibana instances");
+        this.createEnrollmentTokenFunction = createEnrollmentTokenFunction;
+        scope = parser.acceptsAll(List.of("scope", "s"), "The scope of this enrollment token, can be either \"node\" or \"kibana\"")
+            .withRequiredArg()
+            .required();
+    }
+
+    public static void main(String[] args) throws Exception {
+        exit(new CreateEnrollmentTokenTool().main(args, Terminal.DEFAULT));
+    }
+
+    @Override
+    protected void validate(Terminal terminal, OptionSet options, Environment env) throws Exception {
+        if (XPackSettings.ENROLLMENT_ENABLED.get(env.settings()) == false) {
+            throw new UserException(
+                ExitCodes.CONFIG,
+                "[xpack.security.enrollment.enabled] must be set to `true` to create an enrollment token"
+            );
+        }
+        final String tokenScope = scope.value(options);
+        if (ALLOWED_SCOPES.contains(tokenScope) == false) {
+            terminal.errorPrintln("The scope of this enrollment token, can only be one of " + ALLOWED_SCOPES);
+            throw new UserException(ExitCodes.USAGE, "Invalid scope");
+        }
+    }
+
+    @Override
+    protected void executeCommand(Terminal terminal, OptionSet options, Environment env) throws Exception {
+        final String username = getUsername();
+        final String tokenScope = scope.value(options);
+        try (SecureString password = getPassword()) {
+            CreateEnrollmentToken createEnrollmentTokenService = createEnrollmentTokenFunction.apply(env);
+            if (tokenScope.equals("node")) {
+                terminal.println(createEnrollmentTokenService.createNodeEnrollmentToken(username, password));
+            } else {
+                terminal.println(createEnrollmentTokenService.createKibanaEnrollmentToken(username, password));
+            }
+        } catch (Exception e) {
+            terminal.errorPrintln("Unable to create enrollment token for scope [" + tokenScope + "]");
+            throw new UserException(ExitCodes.CANT_CREATE, e.getMessage(), e.getCause());
+        }
+    }
+}