Add a Multi-Project Search Rest Test (#128657)

This commit adds a Rest IT specifically for search in MultiProject.
Everything was already working as expected, but we were a bit light on
explicit testing for search, which as _the_ core capability of
Elasticsearch is worth testing thoroughly and clearly.

test/external-modules/multi-project/src/javaRestTest/java/org/elasticsearch/action/admin/indices/SearchMultiProjectIT.java

@@ -0,0 +1,291 @@
+/*
+ * 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", the "GNU Affero General Public License v3.0 only", and the "Server Side
+ * Public License v 1"; you may not use this file except in compliance with, at
+ * your election, the "Elastic License 2.0", the "GNU Affero General Public
+ * License v3.0 only", or the "Server Side Public License, v 1".
+ */
+
+package org.elasticsearch.action.admin.indices;
+
+import org.elasticsearch.client.Request;
+import org.elasticsearch.client.Response;
+import org.elasticsearch.client.ResponseException;
+import org.elasticsearch.cluster.metadata.ProjectId;
+import org.elasticsearch.common.Strings;
+import org.elasticsearch.common.settings.SecureString;
+import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.util.concurrent.ThreadContext;
+import org.elasticsearch.multiproject.MultiProjectRestTestCase;
+import org.elasticsearch.test.cluster.ElasticsearchCluster;
+import org.elasticsearch.test.cluster.local.LocalClusterSpecBuilder;
+import org.elasticsearch.test.cluster.local.distribution.DistributionType;
+import org.elasticsearch.test.rest.ObjectPath;
+import org.junit.ClassRule;
+import org.junit.Rule;
+import org.junit.rules.TestName;
+
+import java.io.IOException;
+import java.util.List;
+import java.util.Locale;
+import java.util.Map;
+
+import static org.hamcrest.Matchers.aMapWithSize;
+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.greaterThan;
+import static org.hamcrest.Matchers.instanceOf;
+import static org.hamcrest.Matchers.notNullValue;
+
+public class SearchMultiProjectIT extends MultiProjectRestTestCase {
+
+    private static final String PASSWORD = "hunter2";
+
+    @ClassRule
+    public static ElasticsearchCluster cluster = createCluster();
+
+    @Rule
+    public final TestName testNameRule = new TestName();
+
+    private static ElasticsearchCluster createCluster() {
+        LocalClusterSpecBuilder<ElasticsearchCluster> clusterBuilder = ElasticsearchCluster.local()
+            .nodes(1)
+            .distribution(DistributionType.INTEG_TEST)
+            .module("test-multi-project")
+            .setting("test.multi_project.enabled", "true")
+            .setting("xpack.security.enabled", "true")
+            .user("admin", PASSWORD);
+        return clusterBuilder.build();
+    }
+
+    @Override
+    protected String getTestRestCluster() {
+        return cluster.getHttpAddresses();
+    }
+
+    @Override
+    protected Settings restClientSettings() {
+        final String token = basicAuthHeaderValue("admin", new SecureString(PASSWORD.toCharArray()));
+        return Settings.builder().put(ThreadContext.PREFIX + ".Authorization", token).build();
+    }
+
+    public void testSearchIndexThatExistsInMultipleProjects() throws Exception {
+        final ProjectId projectId1 = ProjectId.fromId(randomIdentifier());
+        createProject(projectId1.id());
+
+        final ProjectId projectId2 = ProjectId.fromId(randomIdentifier());
+        createProject(projectId2.id());
+
+        final String indexPrefix = getTestName().toLowerCase(Locale.ROOT);
+        final String indexName = indexPrefix + "-" + randomAlphanumericOfLength(6).toLowerCase(Locale.ROOT);
+
+        createIndex(projectId1, indexName);
+        String docId1 = putDocument(projectId1, indexName, "{\"project\": 1 }", true);
+
+        createIndex(projectId2, indexName);
+        String docId2a = putDocument(projectId2, indexName, "{\"project\": 2, \"doc\": \"a\" }", false);
+        String docId2b = putDocument(projectId2, indexName, "{\"project\": 2, \"doc\": \"b\" }", true);
+
+        List<String> results1 = search(projectId1, indexName);
+        assertThat(results1, containsInAnyOrder(docId1));
+
+        List<String> results2 = search(projectId2, indexName);
+        assertThat(results2, containsInAnyOrder(docId2a, docId2b));
+
+        final var query = """
+            {
+             "query": { "term": { "project": 1 } }
+            }
+            """;
+        results1 = getHitIds(search(projectId1, indexPrefix + "-*", query));
+        assertThat(results1, containsInAnyOrder(docId1));
+
+        results2 = getHitIds(search(projectId2, indexPrefix + "-*", query));
+        assertThat(results2, empty());
+
+        final String aliasName = indexPrefix + "-" + randomIntBetween(100, 999);
+        addAlias(projectId1, indexName, aliasName);
+
+        results1 = search(projectId1, aliasName);
+        assertThat(results1, containsInAnyOrder(docId1));
+
+        assertIndexNotFound(projectId2, aliasName);
+
+        addAlias(projectId2, indexName, aliasName);
+        results2 = search(projectId2, indexName);
+        assertThat(results2, containsInAnyOrder(docId2a, docId2b));
+
+        results1 = search(projectId1, indexPrefix + "-*");
+        assertThat(results1, containsInAnyOrder(docId1));
+    }
+
+    public void testIndexNotVisibleAcrossProjects() throws IOException {
+        final ProjectId projectId1 = ProjectId.fromId(randomIdentifier());
+        createProject(projectId1.id());
+
+        final ProjectId projectId2 = ProjectId.fromId(randomIdentifier());
+        createProject(projectId2.id());
+
+        final String indexPrefix = getTestName().toLowerCase(Locale.ROOT);
+        final String indexName = indexPrefix + "-" + randomAlphanumericOfLength(6).toLowerCase(Locale.ROOT);
+
+        createIndex(projectId1, indexName);
+        String docId1 = putDocument(projectId1, indexName, "{\"project\": 1 }", true);
+
+        List<String> results1 = search(projectId1, indexName);
+        assertThat(results1, containsInAnyOrder(docId1));
+
+        assertIndexNotFound(projectId2, indexName);
+
+        results1 = search(projectId1, indexPrefix + "-*");
+        assertThat(results1, containsInAnyOrder(docId1));
+
+        List<String> results2 = search(projectId2, indexPrefix + "-*");
+        assertThat(results2, empty());
+
+        results2 = search(projectId2, "");
+        assertThat(results2, empty());
+    }
+
+    public void testRequestCacheIsNotSharedAcrossProjects() throws IOException {
+        final ProjectId projectId1 = ProjectId.fromId(randomIdentifier());
+        createProject(projectId1.id());
+
+        final ProjectId projectId2 = ProjectId.fromId(randomIdentifier());
+        createProject(projectId2.id());
+
+        final String indexPrefix = getTestName().toLowerCase(Locale.ROOT);
+        final String indexName = indexPrefix + "-" + randomAlphanumericOfLength(6).toLowerCase(Locale.ROOT);
+
+        createIndex(projectId1, indexName);
+        putDocument(projectId1, indexName, "{\"project\": 1 }", true);
+
+        createIndex(projectId2, indexName);
+        putDocument(projectId2, indexName, "{\"project\": 2, \"doc\": \"a\" }", false);
+        putDocument(projectId2, indexName, "{\"project\": 2, \"doc\": \"b\" }", false);
+        putDocument(projectId2, indexName, "{\"project\": 2, \"doc\": \"c\" }", true);
+
+        final long initialCacheSize = getRequestCacheUsage();
+
+        final var query = """
+            {
+              "size": 0,
+              "aggs": {
+                "proj": { "terms": { "field": "project" } }
+              }
+            }
+            """;
+
+        // Perform a search in project 1 that should be cached in shard request cache
+        // That is, an aggregation with size:0
+        ObjectPath response = search(projectId1, indexName, query);
+        String context = "In search response: " + response;
+        assertThat(context, response.evaluateArraySize("aggregations.proj.buckets"), equalTo(1));
+        assertThat(context, response.evaluate("aggregations.proj.buckets.0.key"), equalTo(1));
+        assertThat(context, response.evaluate("aggregations.proj.buckets.0.doc_count"), equalTo(1));
+
+        final long agg1CacheSize = getRequestCacheUsage();
+        assertThat("Expected aggregation result to be stored in shard request cache", agg1CacheSize, greaterThan(initialCacheSize));
+
+        // Perform the identical search on project 2 and make sure it returns the right results for the project
+        response = search(projectId2, indexName, query);
+        context = "In search response: " + response;
+        assertThat(context, response.evaluateArraySize("aggregations.proj.buckets"), equalTo(1));
+        assertThat(context, response.evaluate("aggregations.proj.buckets.0.key"), equalTo(2));
+        assertThat(context, response.evaluate("aggregations.proj.buckets.0.doc_count"), equalTo(3));
+
+        final long agg2CacheSize = getRequestCacheUsage();
+        assertThat("Expected aggregation result to be stored in shard request cache", agg2CacheSize, greaterThan(agg1CacheSize));
+    }
+
+    private void createIndex(ProjectId projectId, String indexName) throws IOException {
+        Request request = new Request("PUT", "/" + indexName);
+        setRequestProjectId(request, projectId.id());
+        Response response = client().performRequest(request);
+        assertOK(response);
+    }
+
+    private void addAlias(ProjectId projectId, String indexName, String alias) throws IOException {
+        Request request = new Request("POST", "/_aliases");
+        request.setJsonEntity(Strings.format("""
+            {
+              "actions": [
+                {
+                  "add": {
+                    "index": "%s",
+                    "alias": "%s"
+                  }
+                }
+              ]
+            }
+            """, indexName, alias));
+        setRequestProjectId(request, projectId.id());
+        Response response = client().performRequest(request);
+        assertOK(response);
+    }
+
+    private String putDocument(ProjectId projectId, String indexName, String body, boolean refresh) throws IOException {
+        Request request = new Request("POST", "/" + indexName + "/_doc?refresh=" + refresh);
+        request.setJsonEntity(body);
+        setRequestProjectId(request, projectId.id());
+        Response response = client().performRequest(request);
+        assertOK(response);
+        return String.valueOf(entityAsMap(response).get("_id"));
+    }
+
+    private List<String> search(ProjectId projectId, String indexExpression) throws IOException {
+        return getHitIds(search(projectId, indexExpression, null));
+    }
+
+    private static ObjectPath search(ProjectId projectId, String indexExpression, String body) throws IOException {
+        Request request = new Request("GET", "/" + indexExpression + "/_search");
+        if (body != null) {
+            request.setJsonEntity(body);
+        }
+        setRequestProjectId(request, projectId.id());
+        Response response = client().performRequest(request);
+        assertOK(response);
+        return new ObjectPath(entityAsMap(response));
+    }
+
+    private void assertIndexNotFound(ProjectId projectId2, String indexName) {
+        ResponseException ex = expectThrows(ResponseException.class, () -> search(projectId2, indexName));
+        assertThat(ex.getMessage(), containsString("index_not_found"));
+        assertThat(ex.getMessage(), containsString(indexName));
+    }
+
+    private static List<String> getHitIds(ObjectPath searchResponse) throws IOException {
+        List<Map<String, ?>> ids = searchResponse.evaluate("hits.hits");
+        return ids.stream().map(o -> String.valueOf(o.get("_id"))).toList();
+    }
+
+    private long getRequestCacheUsage() throws IOException {
+        final ObjectPath nodeStats = getNodeStats("indices/request_cache");
+        return evaluateLong(nodeStats, "indices.request_cache.memory_size_in_bytes");
+    }
+
+    private static ObjectPath getNodeStats(String stat) throws IOException {
+        Request request = new Request("GET", "/_nodes/stats/" + stat);
+        Response response = client().performRequest(request);
+        assertOK(response);
+        final Map<String, ?> responseMap = entityAsMap(response);
+
+        @SuppressWarnings("unchecked")
+        final Map<String, ?> nodes = (Map<String, ?>) responseMap.get("nodes");
+        assertThat(nodes, aMapWithSize(1));
+
+        ObjectPath nodeStats = new ObjectPath(nodes.values().iterator().next());
+        return nodeStats;
+    }
+
+    private static long evaluateLong(ObjectPath nodeStats, String path) throws IOException {
+        Object size = nodeStats.evaluate(path);
+        assertThat("did not find " + path + " in " + nodeStats, size, notNullValue());
+        assertThat("incorrect type for " + path + " in " + nodeStats, size, instanceOf(Number.class));
+        return ((Number) size).longValue();
+    }
+
+}