Prevent snapshots to be mounted as system indices

x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/action/TransportMountSearchableSnapshotAction.java

@@ -24,6 +24,7 @@
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.index.IndexNotFoundException;
+import org.elasticsearch.indices.InvalidIndexNameException;
 import org.elasticsearch.license.XPackLicenseState;
 import org.elasticsearch.repositories.IndexId;
 import org.elasticsearch.repositories.RepositoriesService;
@@ -132,6 +133,11 @@ protected void masterOperation(
     ) {
         SearchableSnapshots.ensureValidLicense(licenseState);
 
+        final String mountedIndexName = request.mountedIndexName();
+        if (mountedIndexName.charAt(0) == '.') {
+            throw new InvalidIndexNameException(mountedIndexName, "system indices cannot be mounted as searchable snapshots");
+        }
+
         final String repoName = request.repositoryName();
         final String snapName = request.snapshotName();
         final String indexName = request.snapshotIndexName();
@@ -168,7 +174,7 @@ protected void masterOperation(
                         .indices(indexName)
                         // Always rename it to the desired mounted index name
                         .renamePattern(".+")
-                        .renameReplacement(request.mountedIndexName())
+                        .renameReplacement(mountedIndexName)
                         // Pass through index settings, adding the index-level settings required to use searchable snapshots
                         .indexSettings(
                             Settings.builder()

x-pack/plugin/searchable-snapshots/src/test/java/org/elasticsearch/xpack/searchablesnapshots/SearchableSnapshotsSystemIndicesIntegTests.java

@@ -0,0 +1,127 @@
+/*
+ * 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.searchablesnapshots;
+
+import org.elasticsearch.action.admin.cluster.snapshots.create.CreateSnapshotResponse;
+import org.elasticsearch.action.bulk.BulkRequest;
+import org.elasticsearch.action.bulk.BulkResponse;
+import org.elasticsearch.action.index.IndexRequest;
+import org.elasticsearch.client.Client;
+import org.elasticsearch.client.OriginSettingClient;
+import org.elasticsearch.cluster.metadata.IndexMetadata;
+import org.elasticsearch.common.Strings;
+import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.indices.InvalidIndexNameException;
+import org.elasticsearch.indices.SystemIndexDescriptor;
+import org.elasticsearch.plugins.Plugin;
+import org.elasticsearch.plugins.SystemIndexPlugin;
+import org.elasticsearch.xpack.core.ClientHelper;
+import org.elasticsearch.xpack.core.searchablesnapshots.MountSearchableSnapshotAction;
+import org.elasticsearch.xpack.core.searchablesnapshots.MountSearchableSnapshotRequest;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+import java.util.Locale;
+
+import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertAcked;
+import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertHitCount;
+import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.is;
+
+public class SearchableSnapshotsSystemIndicesIntegTests extends BaseSearchableSnapshotsIntegTestCase {
+
+    @Override
+    protected Collection<Class<? extends Plugin>> nodePlugins() {
+        final List<Class<? extends Plugin>> plugins = new ArrayList<>(super.nodePlugins());
+        plugins.add(TestSystemIndexPlugin.class);
+        return plugins;
+    }
+
+    public void testCannotMountSystemIndex() {
+        final String systemIndexName = '.' + randomAlphaOfLength(10).toLowerCase(Locale.ROOT);
+        executeTest(systemIndexName, client());
+    }
+
+    public void testCannotMountSystemIndexWithDescriptor() {
+        // TODO replace STACK_ORIGIN with searchable snapshot origin
+        executeTest(TestSystemIndexPlugin.INDEX_NAME, new OriginSettingClient(client(), ClientHelper.STACK_ORIGIN));
+    }
+
+    private void executeTest(final String indexName, final Client client) {
+        final boolean isHidden = randomBoolean();
+        assertAcked(
+            client.admin()
+                .indices()
+                .prepareCreate(indexName)
+                .setSettings(Settings.builder().put(IndexMetadata.SETTING_INDEX_HIDDEN, isHidden).build())
+        );
+
+        final int nbDocs = scaledRandomIntBetween(0, 100);
+        if (nbDocs > 0) {
+            final BulkRequest bulkRequest = new BulkRequest();
+            for (int i = 0; i < nbDocs; i++) {
+                IndexRequest indexRequest = new IndexRequest(indexName);
+                indexRequest.source("value", i);
+                bulkRequest.add(indexRequest);
+            }
+            final BulkResponse bulkResponse = client.bulk(bulkRequest).actionGet();
+            assertThat(bulkResponse.hasFailures(), is(false));
+        }
+        flushAndRefresh(indexName);
+        assertHitCount(client.prepareSearch(indexName).get(), nbDocs);
+
+        final String repositoryName = randomAlphaOfLength(10).toLowerCase(Locale.ROOT);
+        createRepo(repositoryName);
+
+        final String snapshotName = randomAlphaOfLength(10).toLowerCase(Locale.ROOT);
+        final CreateSnapshotResponse snapshotResponse = client.admin()
+            .cluster()
+            .prepareCreateSnapshot(repositoryName, snapshotName)
+            .setIndices(indexName)
+            .setWaitForCompletion(true)
+            .get();
+
+        final int numPrimaries = getNumShards(indexName).numPrimaries;
+        assertThat(snapshotResponse.getSnapshotInfo().successfulShards(), equalTo(numPrimaries));
+        assertThat(snapshotResponse.getSnapshotInfo().failedShards(), equalTo(0));
+
+        if (randomBoolean()) {
+            assertAcked(client.admin().indices().prepareClose(indexName));
+        } else {
+            assertAcked(client.admin().indices().prepareDelete(indexName));
+        }
+
+        final MountSearchableSnapshotRequest mountRequest = new MountSearchableSnapshotRequest(
+            indexName,
+            repositoryName,
+            snapshotName,
+            indexName,
+            Settings.builder().put(IndexMetadata.SETTING_INDEX_HIDDEN, randomBoolean()).build(),
+            Strings.EMPTY_ARRAY,
+            true
+        );
+
+        final InvalidIndexNameException exception = expectThrows(
+            InvalidIndexNameException.class,
+            () -> client.execute(MountSearchableSnapshotAction.INSTANCE, mountRequest).actionGet()
+        );
+        assertThat(exception.getIndex().getName(), equalTo(indexName));
+        assertThat(exception.getMessage(), containsString("system indices cannot be mounted as searchable snapshots"));
+    }
+
+    public static class TestSystemIndexPlugin extends Plugin implements SystemIndexPlugin {
+
+        static final String INDEX_NAME = ".test-system-index";
+
+        @Override
+        public Collection<SystemIndexDescriptor> getSystemIndexDescriptors(Settings settings) {
+            return List.of(new SystemIndexDescriptor(INDEX_NAME, "System index for [" + getTestClass().getName() + ']'));
+        }
+    }
+}