elastic · jaymode · Jun 2, 2015 · Apr 30, 2015
diff --git a/docs/reference/setup/configuration.asciidoc b/docs/reference/setup/configuration.asciidoc
@@ -264,6 +264,29 @@ file which will resolve to an environment setting, for example:
 }
 --------------------------------------------------
 
+Additionally, for settings that you do not wish to store in the configuration
+file, you can use the value `${prompt::text}` or `${prompt::secret}` and start
+Elasticsearch in the foreground. `${prompt::secret}` has echoing disabled so
+that the value entered will not be shown in your terminal; `${prompt::text}`
+will allow you to see the value as you type it in. For example:
+
+[source,yaml]
+--------------------------------------------------
+node:
+  name: ${prompt::text}
+--------------------------------------------------
+
+On execution of the `elasticsearch` command, you will be prompted to enter
+the actual value like so:
+
+[source,sh]
+--------------------------------------------------
+Enter value for [node.name]:
+--------------------------------------------------
+
+NOTE: Elasticsearch will not start if `${prompt::text}` or `${prompt::secret}`
+is used in the settings and the process is run as a service or in the background.
+
 The location of the configuration file can be set externally using a
 system property:
 

diff --git a/src/main/java/org/elasticsearch/bootstrap/Bootstrap.java b/src/main/java/org/elasticsearch/bootstrap/Bootstrap.java
@@ -25,6 +25,7 @@
 import org.elasticsearch.Version;
 import org.elasticsearch.common.PidFile;
 import org.elasticsearch.common.SuppressForbidden;
+import org.elasticsearch.common.cli.Terminal;
 import org.elasticsearch.common.collect.Tuple;
 import org.elasticsearch.common.inject.CreationException;
 import org.elasticsearch.common.inject.spi.Message;
@@ -163,8 +164,16 @@ public void run() {
 
         // install SM after natives, shutdown hooks, etc.
         setupSecurity(settings, environment);
-
-        NodeBuilder nodeBuilder = NodeBuilder.nodeBuilder().settings(settings).loadConfigSettings(false);
+
+        // We do not need to reload system properties here as we have already applied them in building the settings and
+        // reloading could cause multiple prompts to the user for values if a system property was specified with a prompt
+        // placeholder
+        Settings nodeSettings = Settings.settingsBuilder()
+                .put(settings)
+                .put(InternalSettingsPreparer.IGNORE_SYSTEM_PROPERTIES_SETTING, true)
+                .build();
+
+        NodeBuilder nodeBuilder = NodeBuilder.nodeBuilder().settings(nodeSettings).loadConfigSettings(false);
         node = nodeBuilder.build();
     }
 
@@ -195,8 +204,9 @@ private static void setupLogging(Settings settings, Environment environment) {
         }
     }
 
-    private static Tuple<Settings, Environment> initialSettings() {
-        return InternalSettingsPreparer.prepareSettings(EMPTY_SETTINGS, true);
+    private static Tuple<Settings, Environment> initialSettings(boolean foreground) {
+        Terminal terminal = foreground ? Terminal.DEFAULT : null;
+        return InternalSettingsPreparer.prepareSettings(EMPTY_SETTINGS, true, terminal);
     }
 
     private void start() {
@@ -227,7 +237,7 @@ public static void main(String[] args) {
         Settings settings = null;
         Environment environment = null;
         try {
-            Tuple<Settings, Environment> tuple = initialSettings();
+            Tuple<Settings, Environment> tuple = initialSettings(foreground);
             settings = tuple.v1();
             environment = tuple.v2();
 

diff --git a/src/main/java/org/elasticsearch/common/cli/CliTool.java b/src/main/java/org/elasticsearch/common/cli/CliTool.java
@@ -93,7 +93,7 @@ protected CliTool(CliToolConfig config, Terminal terminal) {
         Preconditions.checkArgument(config.cmds().size() != 0, "At least one command must be configured");
         this.config = config;
         this.terminal = terminal;
-        Tuple<Settings, Environment> tuple = InternalSettingsPreparer.prepareSettings(EMPTY_SETTINGS, true);
+        Tuple<Settings, Environment> tuple = InternalSettingsPreparer.prepareSettings(EMPTY_SETTINGS, true, terminal);
         settings = tuple.v1();
         env = tuple.v2();
     }

diff --git a/src/main/java/org/elasticsearch/common/settings/Settings.java b/src/main/java/org/elasticsearch/common/settings/Settings.java
@@ -1211,7 +1211,7 @@ public Builder putProperties(String prefix, Properties properties, String[] igno
          * tries and resolve it against an environment variable ({@link System#getenv(String)}), and last, tries
          * and replace it with another setting already set on this builder.
          */
-        public Builder replacePropertyPlaceholders() {
+        public Builder replacePropertyPlaceholders(String... ignoredValues) {
             PropertyPlaceholder propertyPlaceholder = new PropertyPlaceholder("${", "}", false);
             PropertyPlaceholder.PlaceholderResolver placeholderResolver = new PropertyPlaceholder.PlaceholderResolver() {
                     @Override
@@ -1241,7 +1241,19 @@ public boolean shouldIgnoreMissing(String placeholderName) {
                     }
                 };
             for (Map.Entry<String, String> entry : Maps.newHashMap(map).entrySet()) {
-                String value = propertyPlaceholder.replacePlaceholders(entry.getValue(), placeholderResolver);
+                String possiblePlaceholder = entry.getValue();
+                boolean ignored = false;
+                for (String ignoredValue : ignoredValues) {
+                    if (ignoredValue.equals(possiblePlaceholder)) {
+                        ignored = true;
+                        break;
+                    }
+                }
+                if (ignored) {
+                    continue;
+                }
+
+                String value = propertyPlaceholder.replacePlaceholders(possiblePlaceholder, placeholderResolver);
                 // if the values exists and has length, we should maintain it  in the map
                 // otherwise, the replace process resolved into removing it
                 if (Strings.hasLength(value)) {

diff --git a/src/main/java/org/elasticsearch/node/internal/InternalSettingsPreparer.java b/src/main/java/org/elasticsearch/node/internal/InternalSettingsPreparer.java
@@ -20,9 +20,11 @@
 package org.elasticsearch.node.internal;
 
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.UnmodifiableIterator;
 import org.elasticsearch.cluster.ClusterName;
 import org.elasticsearch.common.Names;
 import org.elasticsearch.common.Strings;
+import org.elasticsearch.common.cli.Terminal;
 import org.elasticsearch.common.collect.Tuple;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.env.Environment;
@@ -41,10 +43,38 @@ public class InternalSettingsPreparer {
 
     static final List<String> ALLOWED_SUFFIXES = ImmutableList.of(".yml", ".yaml", ".json", ".properties");
 
+    public static final String SECRET_PROMPT_VALUE = "${prompt::secret}";
+    public static final String TEXT_PROMPT_VALUE = "${prompt::text}";
+    public static final String IGNORE_SYSTEM_PROPERTIES_SETTING = "config.ignore_system_properties";
+
+    /**
+     * Prepares the settings by gathering all elasticsearch system properties, optionally loading the configuration settings,
+     * and then replacing all property placeholders. This method will not work with settings that have <code>__prompt__</code>
+     * as their value unless they have been resolved previously.
+     * @param pSettings The initial settings to use
+     * @param loadConfigSettings flag to indicate whether to load settings from the configuration directory/file
+     * @return the {@link Settings} and {@link Environment} as a {@link Tuple}
+     */
     public static Tuple<Settings, Environment> prepareSettings(Settings pSettings, boolean loadConfigSettings) {
+        return prepareSettings(pSettings, loadConfigSettings, null);
+    }
+
+    /**
+     * Prepares the settings by gathering all elasticsearch system properties, optionally loading the configuration settings,
+     * and then replacing all property placeholders. If a {@link Terminal} is provided and configuration settings are loaded,
+     * settings with the <code>__prompt__</code> value will result in a prompt for the setting to the user.
+     * @param pSettings The initial settings to use
+     * @param loadConfigSettings flag to indicate whether to load settings from the configuration directory/file
+     * @param terminal the Terminal to use for input/output
+     * @return the {@link Settings} and {@link Environment} as a {@link Tuple}
+     */
+    public static Tuple<Settings, Environment> prepareSettings(Settings pSettings, boolean loadConfigSettings, Terminal terminal) {
         // ignore this prefixes when getting properties from es. and elasticsearch.
         String[] ignorePrefixes = new String[]{"es.default.", "elasticsearch.default."};
-        boolean useSystemProperties = !pSettings.getAsBoolean("config.ignore_system_properties", false);
+        // ignore the special prompt placeholders since they have the same format as property placeholders and will be resolved
+        // as having a default value because of the ':' in the format
+        String[] ignoredPlaceholders = new String[] { SECRET_PROMPT_VALUE, TEXT_PROMPT_VALUE };
+        boolean useSystemProperties = !pSettings.getAsBoolean(IGNORE_SYSTEM_PROPERTIES_SETTING, false);
         // just create enough settings to build the environment
         Settings.Builder settingsBuilder = settingsBuilder().put(pSettings);
         if (useSystemProperties) {
@@ -53,7 +83,7 @@ public static Tuple<Settings, Environment> prepareSettings(Settings pSettings, b
                     .putProperties("elasticsearch.", System.getProperties(), ignorePrefixes)
                     .putProperties("es.", System.getProperties(), ignorePrefixes);
         }
-        settingsBuilder.replacePropertyPlaceholders();
+        settingsBuilder.replacePropertyPlaceholders(ignoredPlaceholders);
 
         Environment environment = new Environment(settingsBuilder.build());
 
@@ -91,17 +121,17 @@ public static Tuple<Settings, Environment> prepareSettings(Settings pSettings, b
             settingsBuilder.putProperties("elasticsearch.", System.getProperties(), ignorePrefixes)
                     .putProperties("es.", System.getProperties(), ignorePrefixes);
         }
-        settingsBuilder.replacePropertyPlaceholders();
+        settingsBuilder.replacePropertyPlaceholders(ignoredPlaceholders);
 
         // allow to force set properties based on configuration of the settings provided
         for (Map.Entry<String, String> entry : pSettings.getAsMap().entrySet()) {
             String setting = entry.getKey();
             if (setting.startsWith("force.")) {
                 settingsBuilder.remove(setting);
-                settingsBuilder.put(setting.substring(".force".length()), entry.getValue());
+                settingsBuilder.put(setting.substring("force.".length()), entry.getValue());
             }
         }
-        settingsBuilder.replacePropertyPlaceholders();
+        settingsBuilder.replacePropertyPlaceholders(ignoredPlaceholders);
 
         // generate the name
         if (settingsBuilder.get("name") == null) {
@@ -123,7 +153,7 @@ public static Tuple<Settings, Environment> prepareSettings(Settings pSettings, b
             settingsBuilder.put(ClusterName.SETTING, ClusterName.DEFAULT.value());
         }
 
-        Settings v1 = settingsBuilder.build();
+        Settings v1 = replacePromptPlaceholders(settingsBuilder.build(), terminal);
         environment = new Environment(v1);
 
         // put back the env settings
@@ -135,4 +165,45 @@ public static Tuple<Settings, Environment> prepareSettings(Settings pSettings, b
 
         return new Tuple<>(v1, environment);
     }
+
+    static Settings replacePromptPlaceholders(Settings settings, Terminal terminal) {
+        UnmodifiableIterator<Map.Entry<String, String>> iter = settings.getAsMap().entrySet().iterator();
+        Settings.Builder builder = Settings.builder();
+
+        while (iter.hasNext()) {
+            Map.Entry<String, String> entry = iter.next();
+            String value = entry.getValue();
+            String key = entry.getKey();
+            switch (value) {
+                case SECRET_PROMPT_VALUE:
+                    String secretValue = promptForValue(key, terminal, true);
+                    if (Strings.hasLength(secretValue)) {
+                        builder.put(key, secretValue);
+                    }
+                    break;
+                case TEXT_PROMPT_VALUE:
+                    String textValue = promptForValue(key, terminal, false);
+                    if (Strings.hasLength(textValue)) {
+                        builder.put(key, textValue);
+                    }
+                    break;
+                default:
+                    builder.put(key, value);
+                    break;
+            }
+        }
+
+        return builder.build();
+    }
+
+    static String promptForValue(String key, Terminal terminal, boolean secret) {
+        if (terminal == null) {
+            throw new UnsupportedOperationException("found property [" + key + "] with value [" + (secret ? SECRET_PROMPT_VALUE : TEXT_PROMPT_VALUE) +"]. prompting for property values is only supported when running elasticsearch in the foreground");
+        }
+
+        if (secret) {
+            return new String(terminal.readSecret("Enter value for [%s]: ", key));
+        }
+        return terminal.readText("Enter value for [%s]: ", key);
+    }
 }
diff --git a/src/main/java/org/elasticsearch/plugins/PluginManager.java b/src/main/java/org/elasticsearch/plugins/PluginManager.java
@@ -25,6 +25,7 @@
 import org.apache.lucene.util.IOUtils;
 import org.elasticsearch.*;
 import org.elasticsearch.common.SuppressForbidden;
+import org.elasticsearch.common.cli.Terminal;
 import org.elasticsearch.common.collect.Tuple;
 import org.elasticsearch.common.http.client.HttpDownloadHelper;
 import org.elasticsearch.common.io.FileSystemUtils;
@@ -338,7 +339,7 @@ public void listInstalledPlugins() throws IOException {
     private static final int EXIT_CODE_ERROR = 70;
 
     public static void main(String[] args) {
-        Tuple<Settings, Environment> initialSettings = InternalSettingsPreparer.prepareSettings(EMPTY_SETTINGS, true);
+        Tuple<Settings, Environment> initialSettings = InternalSettingsPreparer.prepareSettings(EMPTY_SETTINGS, true, Terminal.DEFAULT);
 
         try {
             Files.createDirectories(initialSettings.v2().pluginsFile());

diff --git a/src/main/java/org/elasticsearch/tribe/TribeService.java b/src/main/java/org/elasticsearch/tribe/TribeService.java
@@ -45,6 +45,7 @@
 import org.elasticsearch.gateway.GatewayService;
 import org.elasticsearch.node.Node;
 import org.elasticsearch.node.NodeBuilder;
+import org.elasticsearch.node.internal.InternalSettingsPreparer;
 import org.elasticsearch.rest.RestStatus;
 
 import java.util.EnumSet;
@@ -128,7 +129,7 @@ public TribeService(Settings settings, ClusterService clusterService, DiscoveryS
             sb.put("node.name", settings.get("name") + "/" + entry.getKey());
             sb.put("path.home", settings.get("path.home")); // pass through ES home dir
             sb.put(TRIBE_NAME, entry.getKey());
-            sb.put("config.ignore_system_properties", true);
+            sb.put(InternalSettingsPreparer.IGNORE_SYSTEM_PROPERTIES_SETTING, true);
             if (sb.get("http.enabled") == null) {
                 sb.put("http.enabled", false);
             }

diff --git a/src/test/java/org/elasticsearch/client/transport/TransportClientRetryTests.java b/src/test/java/org/elasticsearch/client/transport/TransportClientRetryTests.java
@@ -28,6 +28,7 @@
 import org.elasticsearch.cluster.ClusterState;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.transport.TransportAddress;
+import org.elasticsearch.node.internal.InternalSettingsPreparer;
 import org.elasticsearch.plugins.PluginsService;
 import org.elasticsearch.test.ElasticsearchIntegrationTest;
 import org.elasticsearch.test.InternalTestCluster;
@@ -61,7 +62,7 @@ public void testRetry() throws IOException, ExecutionException, InterruptedExcep
                 .put("node.mode", InternalTestCluster.nodeMode())
                 .put("plugins." + PluginsService.LOAD_PLUGIN_FROM_CLASSPATH, false)
                 .put(ClusterName.SETTING, internalCluster().getClusterName())
-                .put("config.ignore_system_properties", true)
+                .put(InternalSettingsPreparer.IGNORE_SYSTEM_PROPERTIES_SETTING, true)
                 .put("path.home", createTempDir());
 
         try (TransportClient transportClient = TransportClient.builder().settings(builder.build()).build()) {

diff --git a/src/test/java/org/elasticsearch/client/transport/TransportClientTests.java b/src/test/java/org/elasticsearch/client/transport/TransportClientTests.java
@@ -25,6 +25,7 @@
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.transport.TransportAddress;
 import org.elasticsearch.node.Node;
+import org.elasticsearch.node.internal.InternalSettingsPreparer;
 import org.elasticsearch.test.ElasticsearchIntegrationTest;
 import org.elasticsearch.test.ElasticsearchIntegrationTest.ClusterScope;
 import org.elasticsearch.transport.TransportService;
@@ -59,7 +60,7 @@ public void testNodeVersionIsUpdated() {
                 .put("path.home", createTempDir())
                 .put("node.name", "testNodeVersionIsUpdated")
                 .put("http.enabled", false)
-                .put("config.ignore_system_properties", true) // make sure we get what we set :)
+                .put(InternalSettingsPreparer.IGNORE_SYSTEM_PROPERTIES_SETTING, true) // make sure we get what we set :)
                 .build()).clusterName("foobar").build();
         node.start();
         try {

diff --git a/src/test/java/org/elasticsearch/common/cli/CliToolTests.java b/src/test/java/org/elasticsearch/common/cli/CliToolTests.java
@@ -25,10 +25,12 @@
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.env.Environment;
+import org.elasticsearch.node.internal.InternalSettingsPreparer;
 import org.junit.Test;
 
 import java.io.IOException;
 import java.util.Map;
+import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.atomic.AtomicReference;
 
 import static org.elasticsearch.common.cli.CliToolConfig.Builder.cmd;
@@ -271,6 +273,49 @@ public CliTool.ExitStatus execute(Settings settings, Environment env) {
         tool.parse("cmd", Strings.splitStringByCommaToArray("--help"));
     }
 
+    @Test
+    public void testPromptForSetting() throws Exception {
+        final AtomicInteger counter = new AtomicInteger();
+        final AtomicReference<String> promptedSecretValue = new AtomicReference<>(null);
+        final AtomicReference<String> promptedTextValue = new AtomicReference<>(null);
+        final Terminal terminal = new MockTerminal() {
+            @Override
+            public char[] readSecret(String text, Object... args) {
+                counter.incrementAndGet();
+                assertThat(args, arrayContaining((Object) "foo.password"));
+                return "changeit".toCharArray();
+            }
+
+            @Override
+            public String readText(String text, Object... args) {
+                counter.incrementAndGet();
+                assertThat(args, arrayContaining((Object) "replace"));
+                return "replaced";
+            }
+        };
+        final NamedCommand cmd = new NamedCommand("noop", terminal) {
+            @Override
+            public CliTool.ExitStatus execute(Settings settings, Environment env) {
+                promptedSecretValue.set(settings.get("foo.password"));
+                promptedTextValue.set(settings.get("replace"));
+                return CliTool.ExitStatus.OK;
+            }
+        };
+
+        System.setProperty("es.foo.password", InternalSettingsPreparer.SECRET_PROMPT_VALUE);
+        System.setProperty("es.replace", InternalSettingsPreparer.TEXT_PROMPT_VALUE);
+        try {
+            new SingleCmdTool("tool", terminal, cmd).execute();
+        } finally {
+            System.clearProperty("es.foo.password");
+            System.clearProperty("es.replace");
+        }
+
+        assertThat(counter.intValue(), is(2));
+        assertThat(promptedSecretValue.get(), is("changeit"));
+        assertThat(promptedTextValue.get(), is("replaced"));
+    }
+
     private void assertStatus(int status, CliTool.ExitStatus expectedStatus) {
         assertThat(status, is(expectedStatus.status()));
     }