test: Replace OldIndexBackwardsCompatibilityIT#testOldClusterStates with a full cluster restart qa test

OldIndexBackwardsCompatibilityIT#testOldClusterStates tested whether global and index metadata could be read from data directory,
 this can also be tested in full cluster qa test that checks cluster state via api.

 Relates to #24939

2 files changed, 8 insertions, 201 deletions

diff --git a/core/src/test/java/org/elasticsearch/VersionTests.java b/core/src/test/java/org/elasticsearch/VersionTests.java
index d8cd635f33..9591ec210d 100644
--- a/core/src/test/java/org/elasticsearch/VersionTests.java
+++ b/core/src/test/java/org/elasticsearch/VersionTests.java
@@ -352,4 +352,12 @@ public class VersionTests extends ESTestCase {
         return result;
     }
 
+    // This exists because 5.1.0 was never released due to a mistake in the release process.
+    // This verifies that we never declare the version as "released" accidentally.
+    // It would never pass qa tests later on, but those come very far in the build and this is quick to check now.
+    public void testUnreleasedVersion() {
+        Version VERSION_5_1_0_UNRELEASED = Version.fromString("5.1.0");
+        VersionTests.assertUnknownVersion(VERSION_5_1_0_UNRELEASED);
+    }
+
 }
diff --git a/core/src/test/java/org/elasticsearch/bwcompat/OldIndexBackwardsCompatibilityIT.java b/core/src/test/java/org/elasticsearch/bwcompat/OldIndexBackwardsCompatibilityIT.java
deleted file mode 100644
index a0ecbf621b..0000000000
--- a/core/src/test/java/org/elasticsearch/bwcompat/OldIndexBackwardsCompatibilityIT.java
+++ /dev/null
@@ -1,201 +0,0 @@
-/*
- * Licensed to Elasticsearch under one or more contributor
- * license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright
- * ownership. Elasticsearch licenses this file to you under
- * the Apache License, Version 2.0 (the "License"); you may
- * not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *    http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-
-package org.elasticsearch.bwcompat;
-
-import org.apache.lucene.util.LuceneTestCase;
-import org.apache.lucene.util.TestUtil;
-import org.elasticsearch.Version;
-import org.elasticsearch.VersionTests;
-import org.elasticsearch.cluster.metadata.IndexMetaData;
-import org.elasticsearch.cluster.metadata.MetaData;
-import org.elasticsearch.common.io.FileSystemUtils;
-import org.elasticsearch.common.settings.Settings;
-import org.elasticsearch.common.xcontent.XContentBuilder;
-import org.elasticsearch.common.xcontent.XContentParser;
-import org.elasticsearch.common.xcontent.XContentType;
-import org.elasticsearch.gateway.MetaDataStateFormat;
-import org.elasticsearch.plugins.Plugin;
-import org.elasticsearch.test.ESIntegTestCase;
-import org.elasticsearch.test.InternalSettingsPlugin;
-import org.elasticsearch.test.OldIndexUtils;
-import org.elasticsearch.test.VersionUtils;
-import org.junit.AfterClass;
-import org.junit.Before;
-
-import java.io.IOException;
-import java.io.InputStream;
-import java.nio.file.Files;
-import java.nio.file.Path;
-import java.util.Arrays;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.List;
-import java.util.Locale;
-import java.util.SortedSet;
-import java.util.TreeSet;
-
-import static org.elasticsearch.test.OldIndexUtils.getIndexDir;
-
-// needs at least 2 nodes since it bumps replicas to 1
-@ESIntegTestCase.ClusterScope(scope = ESIntegTestCase.Scope.TEST, numDataNodes = 0)
-@LuceneTestCase.SuppressFileSystems("ExtrasFS")
-public class OldIndexBackwardsCompatibilityIT extends ESIntegTestCase {
-    // TODO: test for proper exception on unsupported indexes (maybe via separate test?)
-    // We have a 0.20.6.zip etc for this.
-
-
-    @Override
-    protected Collection<Class<? extends Plugin>> nodePlugins() {
-        return Arrays.asList(InternalSettingsPlugin.class);
-    }
-
-    List<String> indexes;
-    List<String> unsupportedIndexes;
-    static String singleDataPathNodeName;
-    static String multiDataPathNodeName;
-    static Path singleDataPath;
-    static Path[] multiDataPath;
-
-    @Before
-    public void initIndexesList() throws Exception {
-        indexes = OldIndexUtils.loadDataFilesList("index", getBwcIndicesPath());
-        unsupportedIndexes = OldIndexUtils.loadDataFilesList("unsupported", getBwcIndicesPath());
-    }
-
-    @AfterClass
-    public static void tearDownStatics() {
-        singleDataPathNodeName = null;
-        multiDataPathNodeName = null;
-        singleDataPath = null;
-        multiDataPath = null;
-    }
-
-    @Override
-    public Settings nodeSettings(int ord) {
-        return OldIndexUtils.getSettings();
-    }
-
-    public void testAllVersionsTested() throws Exception {
-        SortedSet<String> expectedVersions = new TreeSet<>();
-        for (Version v : VersionUtils.allReleasedVersions()) {
-            // The current version is in the "released" list even though it isn't released for historical reasons
-            if (v == Version.CURRENT) continue;
-            if (v.isRelease() == false) continue; // no guarantees for prereleases
-            if (v.before(Version.CURRENT.minimumIndexCompatibilityVersion())) continue; // we can only support one major version backward
-            if (v.equals(Version.CURRENT)) continue; // the current version is always compatible with itself
-            expectedVersions.add("index-" + v.toString() + ".zip");
-        }
-
-        for (String index : indexes) {
-            if (expectedVersions.remove(index) == false) {
-                logger.warn("Old indexes tests contain extra index: {}", index);
-            }
-        }
-        if (expectedVersions.isEmpty() == false) {
-            StringBuilder msg = new StringBuilder("Old index tests are missing indexes:");
-            for (String expected : expectedVersions) {
-                msg.append("\n" + expected);
-            }
-            fail(msg.toString());
-        }
-    }
-
-    private static final Version VERSION_5_1_0_UNRELEASED = Version.fromString("5.1.0");
-
-    public void testUnreleasedVersion() {
-        VersionTests.assertUnknownVersion(VERSION_5_1_0_UNRELEASED);
-    }
-
-    private Path getNodeDir(String indexFile) throws IOException {
-        Path unzipDir = createTempDir();
-        Path unzipDataDir = unzipDir.resolve("data");
-
-        // decompress the index
-        Path backwardsIndex = getBwcIndicesPath().resolve(indexFile);
-        try (InputStream stream = Files.newInputStream(backwardsIndex)) {
-            TestUtil.unzip(stream, unzipDir);
-        }
-
-        // check it is unique
-        assertTrue(Files.exists(unzipDataDir));
-        Path[] list = FileSystemUtils.files(unzipDataDir);
-        if (list.length != 1) {
-            throw new IllegalStateException("Backwards index must contain exactly one cluster");
-        }
-
-        int zipIndex = indexFile.indexOf(".zip");
-        final Version version = Version.fromString(indexFile.substring("index-".length(), zipIndex));
-        if (version.before(Version.V_5_0_0_alpha1)) {
-            // the bwc scripts packs the indices under this path
-            return list[0].resolve("nodes/0/");
-        } else {
-            // after 5.0.0, data folders do not include the cluster name
-            return list[0].resolve("0");
-        }
-    }
-
-    public void testOldClusterStates() throws Exception {
-        // dangling indices do not load the global state, only the per-index states
-        // so we make sure we can read them separately
-        MetaDataStateFormat<MetaData> globalFormat = new MetaDataStateFormat<MetaData>(XContentType.JSON, "global-") {
-
-            @Override
-            public void toXContent(XContentBuilder builder, MetaData state) throws IOException {
-                throw new UnsupportedOperationException();
-            }
-
-            @Override
-            public MetaData fromXContent(XContentParser parser) throws IOException {
-                return MetaData.Builder.fromXContent(parser);
-            }
-        };
-        MetaDataStateFormat<IndexMetaData> indexFormat = new MetaDataStateFormat<IndexMetaData>(XContentType.JSON, "state-") {
-
-            @Override
-            public void toXContent(XContentBuilder builder, IndexMetaData state) throws IOException {
-                throw new UnsupportedOperationException();
-            }
-
-            @Override
-            public IndexMetaData fromXContent(XContentParser parser) throws IOException {
-                return IndexMetaData.Builder.fromXContent(parser);
-            }
-        };
-        Collections.shuffle(indexes, random());
-        for (String indexFile : indexes) {
-            String indexName = indexFile.replace(".zip", "").toLowerCase(Locale.ROOT).replace("unsupported-", "index-");
-            Path nodeDir = getNodeDir(indexFile);
-            logger.info("Parsing cluster state files from index [{}]", indexName);
-            final MetaData metaData = globalFormat.loadLatestState(logger, xContentRegistry(), nodeDir);
-            assertNotNull(metaData);
-
-            final Version version = Version.fromString(indexName.substring("index-".length()));
-            final Path dataDir;
-            if (version.before(Version.V_5_0_0_alpha1)) {
-                dataDir = nodeDir.getParent().getParent();
-            } else {
-                dataDir = nodeDir.getParent();
-            }
-            final Path indexDir = getIndexDir(logger, indexName, indexFile, dataDir);
-            assertNotNull(indexFormat.loadLatestState(logger, xContentRegistry(), indexDir));
-        }
-    }
-
-}