Restricted trust config delegates files to monitor to wrapped trust configuration (elastic/x-pack-elasticsearch#2017)

This change makes the restricted trust configuration delegate the list of files to monitor to the
trust configuration that it wraps so that all files that should be monitored for changes are
monitored for changes.

Relates elastic/x-pack-elasticsearch#1919

Original commit: elastic/x-pack-elasticsearch@227db92ac0

plugin/src/main/java/org/elasticsearch/xpack/ssl/RestrictedTrustConfig.java

@@ -10,6 +10,7 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
@@ -17,7 +18,6 @@ import java.util.Objects;
 
 import org.elasticsearch.ElasticsearchException;
 import org.elasticsearch.common.Nullable;
-import org.elasticsearch.common.io.PathUtils;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.env.Environment;
 
@@ -28,12 +28,12 @@ import org.elasticsearch.env.Environment;
  */
 public final class RestrictedTrustConfig extends TrustConfig {
 
-    public static final String RESTRICTIONS_KEY_SUBJECT_NAME = "trust.subject_name";
+    private static final String RESTRICTIONS_KEY_SUBJECT_NAME = "trust.subject_name";
     private final Settings settings;
     private final String groupConfigPath;
     private final TrustConfig delegate;
 
-    public RestrictedTrustConfig(Settings settings, String groupConfigPath, TrustConfig delegate) {
+    RestrictedTrustConfig(Settings settings, String groupConfigPath, TrustConfig delegate) {
         this.settings = settings;
         this.groupConfigPath = Objects.requireNonNull(groupConfigPath);
         this.delegate = Objects.requireNonNull(delegate);
@@ -52,7 +52,9 @@ public final class RestrictedTrustConfig extends TrustConfig {
 
     @Override
     List<Path> filesToMonitor(@Nullable Environment environment) {
-        return Collections.singletonList(resolveGroupConfigPath(environment));
+        List<Path> files = new ArrayList<>(delegate.filesToMonitor(environment));
+        files.add(resolveGroupConfigPath(environment));
+        return Collections.unmodifiableList(files);
     }
 
     @Override

plugin/src/main/java/org/elasticsearch/xpack/ssl/SSLConfiguration.java

@@ -5,9 +5,7 @@
  */
 package org.elasticsearch.xpack.ssl;
 
-import org.apache.logging.log4j.Logger;
 import org.elasticsearch.common.Nullable;
-import org.elasticsearch.common.logging.Loggers;
 import org.elasticsearch.common.settings.SecureString;
 import org.elasticsearch.common.settings.Setting;
 import org.elasticsearch.common.settings.Settings;

plugin/src/test/java/org/elasticsearch/xpack/ssl/RestrictedTrustConfigTests.java

@@ -0,0 +1,68 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+package org.elasticsearch.xpack.ssl;
+
+import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.env.Environment;
+import org.elasticsearch.test.ESTestCase;
+import org.hamcrest.Matchers;
+
+import javax.net.ssl.X509ExtendedTrustManager;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.List;
+
+public class RestrictedTrustConfigTests extends ESTestCase {
+
+    public void testDelegationOfFilesToMonitor() throws Exception {
+        Path homeDir = createTempDir();
+        Settings settings = Settings.builder().put("path.home", homeDir).build();
+        Environment environment = new Environment(settings);
+
+        final int numOtherFiles = randomIntBetween(0, 4);
+        List<Path> otherFiles = new ArrayList<>(numOtherFiles);
+        for (int i = 0; i < numOtherFiles; i++) {
+            otherFiles.add(Files.createFile(homeDir.resolve("otherFile" + i)));
+        }
+        Path groupConfigPath = Files.createFile(homeDir.resolve("groupConfig"));
+
+        TrustConfig delegate = new TrustConfig() {
+            @Override
+            X509ExtendedTrustManager createTrustManager(Environment environment) {
+                return null;
+            }
+
+            @Override
+            List<Path> filesToMonitor(Environment environment) {
+                return otherFiles;
+            }
+
+            @Override
+            public String toString() {
+                return null;
+            }
+
+            @Override
+            public boolean equals(Object o) {
+                return false;
+            }
+
+            @Override
+            public int hashCode() {
+                return 0;
+            }
+        };
+
+        final RestrictedTrustConfig restrictedTrustConfig = new RestrictedTrustConfig(settings, groupConfigPath.toString(), delegate);
+        List<Path> filesToMonitor = restrictedTrustConfig.filesToMonitor(environment);
+        List<Path> expectedPathList = new ArrayList<>(otherFiles);
+        expectedPathList.add(groupConfigPath);
+
+        assertEquals(numOtherFiles + 1, filesToMonitor.size());
+        assertThat(filesToMonitor, Matchers.contains(expectedPathList.toArray(new Path[0])));
+    }
+}