More flexible settings pattern

libs/entitlement/src/main/java/org/elasticsearch/entitlement/bootstrap/EntitlementBootstrap.java

@@ -35,8 +35,7 @@ public class EntitlementBootstrap {
     public record BootstrapArgs(
         Map<String, Policy> pluginPolicies,
         Function<Class<?>, String> pluginResolver,
-        Function<String, String> settingResolver,
-        Function<String, Stream<String>> settingGlobResolver,
+        Function<String, Stream<String>> settingResolver,
         Path[] dataDirs,
         Path[] sharedRepoDirs,
         Path configDir,
@@ -51,7 +50,6 @@ public record BootstrapArgs(
             requireNonNull(pluginPolicies);
             requireNonNull(pluginResolver);
             requireNonNull(settingResolver);
-            requireNonNull(settingGlobResolver);
             requireNonNull(dataDirs);
             if (dataDirs.length == 0) {
                 throw new IllegalArgumentException("must provide at least one data directory");
@@ -78,8 +76,7 @@ public static BootstrapArgs bootstrapArgs() {
      *
      * @param pluginPolicies a map holding policies for plugins (and modules), by plugin (or module) name.
      * @param pluginResolver a functor to map a Java Class to the plugin it belongs to (the plugin name).
-     * @param settingResolver a functor to resolve the value of an Elasticsearch setting.
-     * @param settingGlobResolver a functor to resolve a glob expression for one or more Elasticsearch settings.
+     * @param settingResolver a functor to resolve a setting name pattern for one or more Elasticsearch settings.
      * @param dataDirs       data directories for Elasticsearch
      * @param sharedRepoDirs       shared repository directories for Elasticsearch
      * @param configDir      the config directory for Elasticsearch
@@ -93,8 +90,7 @@ public static BootstrapArgs bootstrapArgs() {
     public static void bootstrap(
         Map<String, Policy> pluginPolicies,
         Function<Class<?>, String> pluginResolver,
-        Function<String, String> settingResolver,
-        Function<String, Stream<String>> settingGlobResolver,
+        Function<String, Stream<String>> settingResolver,
         Path[] dataDirs,
         Path[] sharedRepoDirs,
         Path configDir,
@@ -113,7 +109,6 @@ public static void bootstrap(
             pluginPolicies,
             pluginResolver,
             settingResolver,
-            settingGlobResolver,
             dataDirs,
             sharedRepoDirs,
             configDir,

libs/entitlement/src/main/java/org/elasticsearch/entitlement/initialization/EntitlementInitialization.java

@@ -144,8 +144,7 @@ private static PolicyManager createPolicyManager() {
             bootstrapArgs.dataDirs(),
             bootstrapArgs.sharedRepoDirs(),
             bootstrapArgs.tempDir(),
-            bootstrapArgs.settingResolver(),
-            bootstrapArgs.settingGlobResolver()
+            bootstrapArgs.settingResolver()
         );
 
         List<Scope> serverScopes = new ArrayList<>();

libs/entitlement/src/main/java/org/elasticsearch/entitlement/runtime/policy/PathLookup.java

@@ -19,6 +19,5 @@ public record PathLookup(
     Path[] dataDirs,
     Path[] sharedRepoDirs,
     Path tempDir,
-    Function<String, String> settingResolver,
-    Function<String, Stream<String>> settingGlobResolver
+    Function<String, Stream<String>> settingResolver
 ) {}

libs/entitlement/src/main/java/org/elasticsearch/entitlement/runtime/policy/entitlements/FilesEntitlement.java

@@ -232,13 +232,7 @@ public PathSettingFileData withExclusive(boolean exclusive) {
 
         @Override
         public Stream<Path> resolveRelativePaths(PathLookup pathLookup) {
-            Stream<String> result;
-            if (setting.contains("*")) {
-                result = pathLookup.settingGlobResolver().apply(setting);
-            } else {
-                String path = pathLookup.settingResolver().apply(setting);
-                result = path == null ? Stream.of() : Stream.of(path);
-            }
+            Stream<String> result = pathLookup.settingResolver().apply(setting);
             if (ignoreUrl) {
                 result = result.filter(s -> s.toLowerCase(Locale.ROOT).startsWith("https://") == false);
             }

libs/entitlement/src/test/java/org/elasticsearch/entitlement/runtime/policy/FileAccessTreeTests.java

@@ -51,7 +51,7 @@ private static Path path(String s) {
         new Path[] { Path.of("/shared1"), Path.of("/shared2") },
         Path.of("/tmp"),
         setting -> settings.get(setting),
-        glob -> settings.getGlobValues(glob)
+        glob -> settings.getValues(glob)
     );
 
     public void testEmpty() {

libs/entitlement/src/test/java/org/elasticsearch/entitlement/runtime/policy/PolicyManagerTests.java

@@ -71,8 +71,7 @@ public static void beforeClass() {
                 new Path[] { TEST_BASE_DIR.resolve("/data1/"), TEST_BASE_DIR.resolve("/data2") },
                 new Path[] { TEST_BASE_DIR.resolve("/shared1"), TEST_BASE_DIR.resolve("/shared2") },
                 TEST_BASE_DIR.resolve("/temp"),
-                Settings.EMPTY::get,
-                Settings.EMPTY::getGlobValues
+                Settings.EMPTY::getValues
             );
         } catch (Exception e) {
             throw new IllegalStateException(e);

libs/entitlement/src/test/java/org/elasticsearch/entitlement/runtime/policy/entitlements/FilesEntitlementTests.java

@@ -48,8 +48,7 @@ public static void setupRoot() {
         new Path[] { Path.of("/data1"), Path.of("/data2") },
         new Path[] { Path.of("/shared1"), Path.of("/shared2") },
         Path.of("/tmp"),
-        setting -> settings.get(setting),
-        glob -> settings.getGlobValues(glob)
+        pattern -> settings.getValues(pattern)
     );
 
     public void testEmptyBuild() {

server/src/main/java/org/elasticsearch/bootstrap/Elasticsearch.java

@@ -248,8 +248,7 @@ private static void initPhase2(Bootstrap bootstrap) throws IOException {
             EntitlementBootstrap.bootstrap(
                 pluginPolicies,
                 pluginsResolver::resolveClassToPluginName,
-                nodeEnv.settings()::get,
-                nodeEnv.settings()::getGlobValues,
+                nodeEnv.settings()::getValues,
                 nodeEnv.dataDirs(),
                 nodeEnv.repoDirs(),
                 nodeEnv.configDir(),

server/src/main/java/org/elasticsearch/common/settings/Settings.java

@@ -291,21 +291,25 @@ public String get(String setting, String defaultValue) {
     }
 
     /**
-     * Returns the values for settings that match the given glob pattern.
-     * A single glob is supported.
+     * Returns the values for the given settings pattern.
      *
-     * @param settingGlob setting name containing a glob
-     * @return zero or more values for any settings in this settings object that match the glob pattern
+     * Either a concrete setting name, or a pattern containing a single glob is supported.
+     *
+     * @param settingPattern name of a setting or a setting name pattern containing a glob
+     * @return zero or more values for any settings in this settings object that match the given pattern
      */
-    public Stream<String> getGlobValues(String settingGlob) {
-        int globIndex = settingGlob.indexOf(".*.");
+    public Stream<String> getValues(String settingPattern) {
+        int globIndex = settingPattern.indexOf(".*.");
+        Stream<String> settingNames;
         if (globIndex == -1) {
-            throw new IllegalArgumentException("Pattern [" + settingGlob + "] does not contain a glob [*]");
+            settingNames = Stream.of(settingPattern);
+        } else {
+            String prefix = settingPattern.substring(0, globIndex + 1);
+            String suffix = settingPattern.substring(globIndex + 2);
+            Settings subSettings = getByPrefix(prefix);
+            settingNames = subSettings.names().stream().map(k -> prefix + k + suffix);
         }
-        String prefix = settingGlob.substring(0, globIndex + 1);
-        String suffix = settingGlob.substring(globIndex + 2);
-        Settings subSettings = getByPrefix(prefix);
-        return subSettings.names().stream().map(k -> k + suffix).map(subSettings::get).filter(Objects::nonNull);
+        return settingNames.map(this::getAsList).flatMap(List::stream).filter(Objects::nonNull);
     }
 
     /**

server/src/test/java/org/elasticsearch/common/settings/SettingsTests.java

@@ -44,6 +44,7 @@
 import static org.hamcrest.Matchers.contains;
 import static org.hamcrest.Matchers.containsInAnyOrder;
 import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.empty;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.hasToString;
 import static org.hamcrest.Matchers.is;
@@ -704,9 +705,21 @@ public void testProcessSetting() throws IOException {
     }
 
     public void testGlobValues() throws IOException {
-        Settings test = Settings.builder().put("foo.x.bar", "1").put("foo.y.bar", "2").build();
-        var values = test.getGlobValues("foo.*.bar").toList();
+        Settings test = Settings.builder().put("foo.x.bar", "1").build();
+
+        // no values
+        assertThat(test.getValues("foo.*.baz").toList(), empty());
+        assertThat(test.getValues("fuz.*.bar").toList(), empty());
+
+        var values = test.getValues("foo.*.bar").toList();
+        assertThat(values, containsInAnyOrder("1"));
+
+        test = Settings.builder().put("foo.x.bar", "1").put("foo.y.bar", "2").build();
+        values = test.getValues("foo.*.bar").toList();
         assertThat(values, containsInAnyOrder("1", "2"));
+
+        values = test.getValues("foo.x.bar").toList();
+        assertThat(values, contains("1"));
     }
 
 }